diff --git a/marked/Y/T-REC-F.747.8-201511-I_PDF-E/raw.md b/marked/Y/T-REC-F.747.8-201511-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..8720838b710185d9bd39785f7fe8bcef0057f9f4 --- /dev/null +++ b/marked/Y/T-REC-F.747.8-201511-I_PDF-E/raw.md @@ -0,0 +1,620 @@ + + +# ITU-T + +# Y.4412/F.747.8 + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +(11/2015) + +SERIES Y: GLOBAL INFORMATION +INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS +AND NEXT-GENERATION NETWORKS, INTERNET OF +THINGS AND SMART CITIES + +Internet of things and smart cities and communities – +Frameworks, architectures and protocols + +SERIES F: NON-TELEPHONE TELECOMMUNICATION +SERVICES + +# --- **Requirements and reference architecture for audience-selectable media service framework in the IoT environment** + +Recommendation ITU-T Y.4412/F.747.8 + +## ITU-T Y-SERIES RECOMMENDATIONS + +## GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS, INTERNET OF THINGS AND SMART CITIES + +## GLOBAL INFORMATION INFRASTRUCTURE + +| | | +|-------------------------------------------|-------------| +| General | Y.100–Y.199 | +| Services, applications and middleware | Y.200–Y.299 | +| Network aspects | Y.300–Y.399 | +| Interfaces and protocols | Y.400–Y.499 | +| Numbering, addressing and naming | Y.500–Y.599 | +| Operation, administration and maintenance | Y.600–Y.699 | +| Security | Y.700–Y.799 | +| Performances | Y.800–Y.899 | + +## INTERNET PROTOCOL ASPECTS + +| | | +|--------------------------------------------------------------------|---------------| +| General | Y.1000–Y.1099 | +| Services and applications | Y.1100–Y.1199 | +| Architecture, access, network capabilities and resource management | Y.1200–Y.1299 | +| Transport | Y.1300–Y.1399 | +| Interworking | Y.1400–Y.1499 | +| Quality of service and network performance | Y.1500–Y.1599 | +| Signalling | Y.1600–Y.1699 | +| Operation, administration and maintenance | Y.1700–Y.1799 | +| Charging | Y.1800–Y.1899 | +| IPTV over NGN | Y.1900–Y.1999 | + +## NEXT GENERATION NETWORKS + +| | | +|-------------------------------------------------------------------|---------------| +| Frameworks and functional architecture models | Y.2000–Y.2099 | +| Quality of Service and performance | Y.2100–Y.2199 | +| Service aspects: Service capabilities and service architecture | Y.2200–Y.2249 | +| Service aspects: Interoperability of services and networks in NGN | Y.2250–Y.2299 | +| Enhancements to NGN | Y.2300–Y.2399 | +| Network management | Y.2400–Y.2499 | +| Network control architectures and protocols | Y.2500–Y.2599 | +| Packet-based Networks | Y.2600–Y.2699 | +| Security | Y.2700–Y.2799 | +| Generalized mobility | Y.2800–Y.2899 | +| Carrier grade open environment | Y.2900–Y.2999 | + +## FUTURE NETWORKS + +| | | +|-----------------|---------------| +| CLOUD COMPUTING | Y.3000–Y.3499 | +| | Y.3500–Y.3999 | + +## INTERNET OF THINGS AND SMART CITIES AND COMMUNITIES + +| | | +|---------------------------------------------------------|----------------------| +| General | Y.4000–Y.4049 | +| Definitions and terminologies | Y.4050–Y.4099 | +| Requirements and use cases | Y.4100–Y.4249 | +| Infrastructure, connectivity and networks | Y.4250–Y.4399 | +| Frameworks, architectures and protocols | Y.4400–Y.4549 | +| Services, applications, computation and data processing | Y.4550–Y.4699 | +| Management, control and performance | Y.4700–Y.4799 | +| Identification and security | Y.4800–Y.4899 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +## Recommendation ITU-T Y.4412/F.747.8 + +# Requirements and reference architecture for audience-selectable media service framework in the IoT environment + +## Summary + +Recommendation ITU-T Y.4412/F.747.8 describes requirements and reference architecture for the audience-selectable media (ASM) service framework. The ASM service provides audiences with media selection options according to their interests and preferences. Examples of media selection options include the selection of an object of interest, and the selection of an interested camera object among multi-camera objects providing different views. + +## History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|----------------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T Y.4412/F.747.8 | 2015-11-29 | 16 | 11.1002/1000/12620 | + +## Keywords + +ASM, audience-selectable, Internet of things, media. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. For example, . + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2016 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | | Page | +|---|------------------------------------------------------------------------------|------| +| 1 | Scope..... | 1 | +| 2 | References..... | 1 | +| 3 | Definitions ..... | 1 | +| | 3.1 Terms defined elsewhere..... | 1 | +| | 3.2 Terms defined in this Recommendation..... | 2 | +| 4 | Abbreviations and acronyms ..... | 2 | +| 5 | Conventions ..... | 2 | +| 6 | Overview of audience-selectable media (ASM) service ..... | 2 | +| 7 | Requirements of ASM service framework ..... | 4 | +| | 7.1 Service requirements ..... | 4 | +| | 7.2 Functional requirements ..... | 4 | +| 8 | Reference architecture of ASM service framework ..... | 5 | +| | 8.1 Reference architecture ..... | 5 | +| | 8.2 Camera objects function ..... | 7 | +| | 8.3 Camera control server function ..... | 8 | +| | 8.4 Video playback terminal function ..... | 9 | +| | Appendix I – Use cases for ASM service ..... | 10 | +| | I.1 Use case for an ASM broadcasting service using multi-camera objects..... | 10 | +| | I.2 Use case for an open screen service using multi-camera objects ..... | 11 | +| | Bibliography..... | 13 | + +## **Introduction** + +Recently, demands for personalized media and interactivity in the media service are increasing and media service platforms are needed to support the fast development and deployment of new multimedia services/applications by reconfiguration of the existing service components. Due to the expansion of the Internet of things (IoT), objects related to media services can be identified and recognized by people or other objects. Also, the IoT enables person-to-object and object-to-object communications as well as person-to-person communication. + +Audience-selectable media (ASM) service enables viewers to be interactive and select preferred media in the running time by providing media selection options. + +## Recommendation ITU-T Y.4412/F.747.8 + +# Requirements and reference architecture for audience-selectable media service framework in the IoT environment + +## 1 Scope + +This Recommendation defines requirements and reference architecture for audience-selectable media (ASM) service in the Internet of things (IoT). The scope of this Recommendation includes: + +- concept of ASM service framework; +- requirements of ASM service framework; +- reference architecture of ASM service framework; and +- functional entities of ASM service framework. + +## 2 References + +None. + +## 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 device** [b-ITU-T Y.4400]: An apparatus through which a user can perceive and interact with the web. + +**3.1.2 Internet of things** [b-ITU-T Y.4000]: A global infrastructure for the information society, enabling advanced services by interconnecting (physical and virtual) things based on existing and evolving interoperable information and communication technologies. + +NOTE 1 – Through the exploitation of identification, data capture, processing and communication capabilities, the IoT makes full use of things to offer services to all kinds of applications, whilst ensuring that security and privacy requirements are fulfilled. + +NOTE 2 – From a broader perspective, the IoT can be perceived as a vision with technological and societal implications. + +**3.1.3 object** [b-ITU-T Y.2002]: An intrinsic representation of an entity that is described at an appropriate level of abstraction in terms of its attributes and functions. + +**3.1.4 resources** [b-ITU-T Y.4400]: The term "resource" is whatever might be identified by a URI. + +NOTE – Familiar examples include an electronic document, an image, a source of information with a consistent purpose (e.g., "today's weather report for Los Angeles"), a service (e.g., an HTTP-to-SMS gateway), and a collection of other resources. A resource is not necessarily accessible via the Internet; e.g., human beings, corporations, and bound books in a library can also be resources. Likewise, abstract concepts can be resources, such as the operators and operands of a mathematical equation, the types of a relationship (e.g., "parent" or "employee"), or numeric values (e.g., zero, one, and infinity). + +**3.1.5 thing** [b-ITU-T Y.4000]: With regard to the Internet of things, this is an object of the physical world (physical things) or the information world (virtual things), which is capable of being identified and integrated into communication networks. + +### 3.2 Terms defined in this Recommendation + +This Recommendation defines the following terms: + +**3.2.1 camera control server:** A server that selects and updates camera objects, camera object groups, and the main camera object. It also controls camera objects. + +**3.2.2 camera object:** A device that captures and tracks objects of interest. It can also transmit and receive the tracked position of each object of interest to both other camera devices and a camera control server through the Internet. Its pan-tilt-zoom may be controlled by the camera control server for tracking objects of interest. + +**3.2.3 camera object group:** A group of camera objects that capture the same object of interest whose occupied region size in the frame is greater than the pre-defined value. + +**3.2.4 main camera object:** A camera object that captures a main broadcasting video. The initial main camera object is selected by audiences or the broadcaster. The main camera object can be changed to the sub-camera object during the service. + +**3.2.5 object of interest:** A moving person or a moving thing in the video of which the service audience may have interest. + +**3.2.6 sub-camera object:** A camera object that is not selected as a main camera object. An initial sub-camera object is usually selected by the broadcaster. The sub-camera object can be changed to the main camera object by audiences during the service. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|-------|-----------------------------| +| ASM | Audience-Selectable Media | +| FE | Functional Entity | +| ID | Identifier | +| IoT | Internet of Things | +| URI | Uniform Resource Identifier | +| Wi-Fi | Wireless Fidelity | + +## 5 Conventions + +None. + +## 6 Overview of audience-selectable media (ASM) service + +Internet of things (IoT) and web of things (WoT) enable physical devices to be accessed as resources and services/applications of the web. + +As new multimedia services/applications are emerging, media service platforms need to support fast development and deployment of new multimedia services/applications by reconfiguration of the existing service components. Also, media service devices, such as cameras, are beginning to provide wireless fidelity (Wi-Fi) technology. + +IoT-applied media service enables objects in media service to be identified and recognized by people or other objects; IoT also enables person-to-object and object-to-object communications as well as person-to-person. This realizes the smart media service where objects can be automatically reconfigured to create and deliver media content according to the audience's demands and preferences. + +In the current broadcasting service, a suitable camera object is selected among available camera objects, video from the selected camera object is encoded, and the encoded video is broadcasted to viewers. Attributes of the content and service region are considered for broadcasting. + +This traditional broadcasting service does not provide any options to audiences to select various views from different camera objects in the same scene. The lack of this option causes audiences to remain passive. + +The ASM service enables audiences to be interactive and select preferred media in the running time by providing media selection options. Examples of media selection options include the selection of an object of interest and a selection of an interested camera object among multi-camera objects providing different views. Figure 1 illustrates the concept of the ASM service. + +As described in Figure 1, there are three components in the ASM service: Broadcaster, audience, and camera management server. These components generate and update object of interest, camera group for each object of interest, and a camera view-video that the audience is interested in, including the following: + +- (1) **broadcaster**: The broadcaster shows object of interest candidates to the audience. +- (2) **audience**: The audience selects one object from the object of interest candidates, selects one of the camera objects in the camera group for the selected object of interest, and watches the selected camera view-video. +- (3) **camera management server**: The camera management server updates the cameras in each camera group for each object of interest, gets the selection option inputs from the audience, and broadcasts the selected camera-view video to the audience. + +![Figure 1: Concept of ASM service diagram. The diagram shows the interaction between a Camera management server, a Broadcaster, and an Audience. The Camera management server manages camera groups for different players. The Broadcaster shows object of interest candidates to the Audience. The Audience selects a camera group, which is then updated by the Camera management server.](367926125450c2bc3f4bdca9d59a62ba_img.jpg) + +The diagram illustrates the ASM service architecture and its flow. At the top is the **Camera management server**. It manages two main camera groups: **Camera group A for player 1** (containing Camera 1 and Camera 2) and **Camera group B for player 2** (containing Camera 4 and Camera 5). An **Update** arrow points from Camera group B to an updated version of Camera group B (containing Camera 4, Camera 5, and Camera 6). Below the server is the **Broadcaster**, which receives input from the server and provides **Object of interest candidates** (Player 1 and Player 2) to the **Audience**. The Audience selects a camera group (Camera 4 and Camera 5) for player 2. This selection is then **Updated** to a new camera group (Camera 4 and Camera 6) for player 2, which is then broadcasted back to the Audience. The diagram is labeled Y.4412-F.747.8(15)\_F01. + +Figure 1: Concept of ASM service diagram. The diagram shows the interaction between a Camera management server, a Broadcaster, and an Audience. The Camera management server manages camera groups for different players. The Broadcaster shows object of interest candidates to the Audience. The Audience selects a camera group, which is then updated by the Camera management server. + +**Figure 1 – Concept of ASM service** + +The concept of the ASM service described in Figure 1 can be explained as follows: + +- broadcasters first specify the object of interest candidates in the scene (e.g., player 1 and player 2) and then show them to the audience for selection; + +- the camera management server constitutes an initial corresponding camera group for each object of interest candidate using all available cameras based on the positions of each object of interest, and each camera; +- an audience first selects one object from the object of interest candidates (e.g., player 2), and also selects one of the cameras in the selected camera group (e.g., camera 5 in camera group B); +- the camera management server receives the audience's selections for the camera and object of interest, and broadcasts a selected camera-view video (e.g., camera 5 in camera group B); +- as an object of interest (e.g., player 2) moves in the scene during the running time, the camera management server updates each member of each camera group based on the updated position of each object of interest (e.g., In Figure 1, camera 5 in the initial camera group B is deleted from the updated camera group B); +- with updated camera members of each group, the camera management server shows each updated selectable camera list for each object of interest; +- then, an audience may change which camera view to watch (e.g., from camera 5 in initial camera group B to camera 6 in updated camera group B). + +## **7 Requirements of ASM service framework** + +### **7.1 Service requirements** + +#### **7.1.1 Media selection option** + +The ASM service is required to provide audiences with: + +- media selection option to select media according to their interests and preferences; +- video selection option to select one camera object among multi-camera objects; +- switching option to change the current camera object to another camera object among multi-camera objects. + +#### **7.1.2 Object of interest selection option** + +The ASM service is required to: + +- provide audiences with a selection option of object of interest to select an object they wish to watch; +- support audiences with changing option of object of interest to in the running time; +- support identification of each object of interest with an appropriate identifier (ID). + +#### **7.1.3 Main camera object selection option** + +- the ASM service is required to provide audiences with a main camera object selection option among multi-camera objects. + +#### **7.1.4 Camera object group selection option** + +- the ASM service is required to provide audiences with the choice of a camera object group selection that captures each object of interest among multi-camera object groups according to their preferences. + +### **7.2 Functional requirements** + +#### **7.2.1 Functional requirements of a camera object** + +Each camera object is required to: + +- be able to obtain the position or the tracking result of an audience-selected object of interest in each captured frame; +- receive the positions or the tracking results of an audience-selected object of interest in each frame of the main camera object as a sub-camera object; +- convert the tracked position of an audience-selected object of interest in the main camera object to the position of each camera object; +- receive audience's video selection information from the video playback terminal through the camera control server; +- share an ID of each tracked object of interest with other camera objects within the same camera object group. + +Each camera object selected as a main camera object is required to: + +- transmit the positions or the tracking result of an audience-selected object of interest in each frame to the other sub-camera objects and the camera control server. + +#### **7.2.2 Functional requirements of camera control server** + +A camera control server is required to: + +- select camera objects that should be shown to the audience for selection; +- update members of each camera object group based on the tracking results of the audience-selected object of interest within the appropriate time interval; +- update the main camera object candidates in each camera object group based on the tracking results of the audience-selected object of interest within the appropriate time interval; +- recommend the main camera object candidates in each camera object group to the audiences based on the tracking results of the object of interest; +- notify audiences of updates of members in each camera object group; +- receive audience's selection information such as an object of interest selection, camera object group selection, and main camera object selection; +- notify audience's selection information to each audience-selected camera object for video transmission to the audience's video playback terminal; +- receive the positions or the tracking results of the audience-selected object of interest in each frame of all camera objects within the appropriate time interval; +- manage each camera object member within each camera object group according to the movement of each object of interest. + +A camera control server is recommended to: + +- control the pan-tilt-zoom of each sub-camera object according to the tracked position and the size of the object of interest in the frame of the main camera object. + +## **8 Reference architecture of ASM service framework** + +### **8.1 Reference architecture** + +Figure 2 shows a reference architecture of the ASM service framework which consists of ASM service framework functions, functional entities (FEs) of each ASM service framework function, reference points between each ASM service framework function. + +![Figure 2: Reference architecture of ASM service framework. The diagram shows three main functional blocks: Camera objects function, Camera control server function, and Video playback terminal function. The Camera objects function contains three FEs: Object of interest processing FE, Camera-to-camera communication FE, and Video transmission FE. The Camera control server function contains three FEs: Main camera object management FE, Camera object group management FE, and Camera pan-tilt-zoom control FE. The Video playback terminal function contains two FEs: Audience's selection options management FE and Video play FE. An Audience is shown interacting with a computer. Information flows are indicated by arrows: I_CO-CS (bidirectional) between Camera objects and Camera control server; I_CO-VP (bidirectional) between Camera objects and Video playback terminal; I_VP-CS (bidirectional) between Video playback terminal and Camera control server; and I_VP-AU (bidirectional) between Video playback terminal and Audience. A reference point Y.4412-F.747.8(15)_F02 is noted near the Audience.](d4af765160d04ecef538e5066006dc77_img.jpg) + +Figure 2: Reference architecture of ASM service framework. The diagram shows three main functional blocks: Camera objects function, Camera control server function, and Video playback terminal function. The Camera objects function contains three FEs: Object of interest processing FE, Camera-to-camera communication FE, and Video transmission FE. The Camera control server function contains three FEs: Main camera object management FE, Camera object group management FE, and Camera pan-tilt-zoom control FE. The Video playback terminal function contains two FEs: Audience's selection options management FE and Video play FE. An Audience is shown interacting with a computer. Information flows are indicated by arrows: I\_CO-CS (bidirectional) between Camera objects and Camera control server; I\_CO-VP (bidirectional) between Camera objects and Video playback terminal; I\_VP-CS (bidirectional) between Video playback terminal and Camera control server; and I\_VP-AU (bidirectional) between Video playback terminal and Audience. A reference point Y.4412-F.747.8(15)\_F02 is noted near the Audience. + +**Figure 2 – Reference architecture of ASM service framework** + +As shown in Figure 2, there are three ASM service framework functions: camera objects function, camera control server function and video playback terminal function. Each function is described as follows in terms of supported functions, supported information, and supported FEs: + +- **camera objects function:** A camera objects function tracks an object of interest, communicates the updated status of the object of interest to the camera control server function, and transmits the audience-selected video to the video playback terminal function. Based on these functional descriptions, the camera objects function includes three FEs of object of interest processing, communication, and video transmission; +- **camera control server function:** The camera control server function manages the main camera object based on the audience's selection, updates the camera object group based on the tracking result of the object of interest, and controls each camera object using the calculated pan, tilt, and, zoom values. Camera control server function contains three FEs of main camera object management, camera object group management, and camera pan-tilt-zoom control; +- **video playback terminal function:** Video playback terminal function receives the audience's selection options, transmits the audience's selection information to the camera objects function and camera control sever function, and plays the audience-selected video. The video playback terminal function consists of two FEs of the audience's selection management and video play. + +As illustrated in Figure 2, there are four reference points: $I_{CO-CS}$ , $I_{CO-VP}$ , $I_{VP-CS}$ , and $I_{VP-AU}$ as follows: + +- **$I_{CO-CS}$ :** $I_{CO-CS}$ is a reference point between the camera objects function and the camera control server function. The position of the object of interest is transferred from the camera objects function to the camera control server function. On the other hand, updated information, including object of interest selection, main camera object selection, camera object group selection, and camera control (e.g., pan, tilt, and zoom values of each camera object) information is transferred from the camera control server function to camera objects function; +- **$I_{CO-VP}$ :** $I_{CO-VP}$ is a reference point between the camera object function and video playback terminal function. The camera objects function sends the audience-selected video to the video playback terminal function. Also, the playback terminal function sends the audience's selection information and playing options to the camera objects function; + +- **IVP-CS:** IVP-CS is a reference point between the video playback terminal function and camera control server function. Through this reference point, video playback terminal transfers the audience's selection information and playing options to the camera control server function. Also, the video playback terminal function transmits the updated information, including the main camera object selection information (for each camera object group), camera object group selection information (for each object of interest), and camera control information for each camera object to the camera control server function; +- **IVP-AU:** IVP-AU is a reference point between the video playback terminal function and the audience. The video playback terminal function shows a list of the audience's selection options available to the audience. The video playback terminal function then receives the audience's selection information and playing options from the audience. Through this reference point, the video playback terminal function shows the current status of each camera object group, current camera control status of each camera object, currently-selected main camera object, position of each object of interest, multi-camera video thumbnails, and audience-selected video with selected playing options during the service. + +### **8.2 Camera objects function** + +The camera objects function: + +- consists of object of interest processing, communication, and video transmission FEs. + +#### **8.2.1 Object of interest processing FE** + +The object of interest processing FE: + +- obtains the ID and the position or the tracking result of the audience-selected object of interest in each captured frame through object of interest extraction and tracking; +- identifies an object of interest in order to provide positional information of each object of interest that is used for generating and updating its corresponding camera object group in camera control server function; +- converts the tracked position of the audience-selected object of interest in the main camera object to the position in each frame captured by its sub-camera object using the camera position and pose information. + +#### **8.2.2 Communication FE** + +The communications FE: + +- transmits the ID and the positions or the tracking results of an audience-selected object of interest in each captured frame to the other sub-camera objects and the camera control server function when one of the camera object functions is selected as a main camera object; +- receives the positions or the tracking result of the audience-selected object of interest in each frame of the main camera object when one of the camera objects is selected as a sub-camera object; +- receives the audience's selection information such as an object of interest selection, a main camera object selection in a camera object group, a selection of an interested camera object among multi-camera objects, video playback terminal selection, and camera object group selection from the video playback terminal function; +- receives the camera control information such as pan-tilt-zoom values from camera pan-tilt-zoom control FE of the camera control server function. + +#### **8.2.3 Video transmission FE** + +The video transmission FE: + +- transmits a video stream of the main camera object selected by audience to the video playback terminal function. + +### **8.3 Camera control server function** + +The camera control server function: + +- consists of main camera object management, camera object group management, and optional camera pan-tilt-zoom control FEs. + +#### **8.3.1 Main camera object management FE** + +The main camera object management FE: + +- receives the audience's main camera object selection information from the video playback terminal function; +- updates the main camera object candidates in each camera object group for updating based on the tracking results of the audience-selected object of interest transmitted from the object of interest processing FE within appropriate intervals; +- recommends the main camera object candidates in each camera object group to the audiences based on the tracking results of the object of interest when the main camera object needs to be updated; +- notifies the audience's selection to the newly audience-selected main camera object in order to track the selected object of interest and transmit an audience-selected video when the audience's main camera object selection information is updated from the video playback terminal function. + +#### **8.3.2 Camera object group management FE** + +The camera object group management FE: + +- initially generates camera object groups according to each identified object of interest; +- classifies each camera object into its corresponding camera object group according to the existence of identified objects of interest in camera objects; +- receives the position or the tracking result of the audience-selected object of interest in each frame from all the camera objects in the group within appropriate time interval; +- updates the members of each camera object group based on the tracking result of each audience-selected object of interest; +- notifies member updates in each camera object group to the audiences. + +#### **8.3.3 Camera pan-tilt-zoom control FE** + +The camera pan-tilt-zoom control FE: + +- calculates pan, tilt, and zoom values of each sub-camera object according to the position and the size of the object of interest in the frame of the main camera object in order to make camera objects within the same camera object group look at the same object of interest; +- transmits the calculated pan, tilt, and zoom values of sub-camera objects to each corresponding sub-camera object within the same camera object group in order to control the sub-camera objects, respectively. + +### **8.4 Video playback terminal function** + +The video playback terminal function: + +- consists of the audience's selection options management and video play FEs. + +#### **8.4.1 Audience's selection options management FE** + +The audience's selection options management FE: + +- shows a list of available audience selection options to the audience; +- receives audience's selection information from the audience; +- transmits audience's selection information to the camera control server function; +- transmits audience's selection information to each camera object function; +- includes options of an object of interest selection, a main camera object selection, and a selection of interested camera objects among multi-camera objects providing different views; +- includes the audience's choices among available audience selection options. + +#### **8.4.2 Video play FE** + +The video play FE: + +- receives an audience-selected video from the camera object function; +- shows a current status of each camera object group, a current camera control status of each camera object, a currently-selected main camera object, the position of each object of interest, multi-camera video thumbnails, and an audience-selected video with audience-selected playing options; +- plays an audience-selected video; +- controls a playing status of the current audience-selected video with audience-selected playing options. + +# Appendix I + +## Use cases for ASM service + +(This appendix does not form an integral part of this Recommendation.) + +### I.1 Use case for an ASM broadcasting service using multi-camera objects + +Figure I.1 shows a use case for an ASM broadcasting service using multi-camera objects. This use case provides audiences with a selection option of choosing a video media from one camera object amongst multi-camera objects that capture a person (an object of interest) whom an audience is interested in. It also provides a selection option of switching a video media from one camera object to another camera object. + +![Figure I.1 - Use case for ASM broadcasting service using multi-camera objects](fc857414626a8d94d132e12d9afe52a4_img.jpg) + +The diagram illustrates the workflow of an ASM broadcasting service. At the top, a 'Broadcaster' icon is shown. Arrows labeled (2) point to three 'Camera object groups' (COG): 'COG 1 for P1', 'COG 2 for P2', and 'COG for P3'. Each COG contains multiple camera icons (e.g., (10), (11)) connected by double-headed arrows indicating 'Sharing of object of interest position by cam-to-cam communication'. A 'Camera control server object' is connected to these groups via arrow (12). Below the COGs, a sports arena image shows players P1, P2, and P3, with camera labels A-F and X-Z. Arrow (9) connects COGs to this scene. An 'Audience' icon is shown on the left, interacting with a 'Video streaming server object' via arrows (3), (4), (5), (6), (8). Arrow (1) connects the Broadcaster to the Audience. At the bottom, two 'Main Camera' views are shown: one for P1 (yellow) and one for P3 (red), displaying the selected player and thumbnail options for other cameras (Cam A, B, C for P1; Cam V, W, Z for P3). A legend indicates solid arrows for 'Inclusion of camera object' and dashed arrows for 'Exclusion of camera object'. + +Figure I.1 - Use case for ASM broadcasting service using multi-camera objects + +**Figure I.1 – Use case for ASM broadcasting service using multi-camera objects** + +In this use case, there is the assumption that each audience has its own object of interest (e.g., a person such as a sports player or famous actress or actor) in the broadcasted video and each object of interest appears and disappears in some camera objects and frames. + +- (1) broadcasters predefine object of interest candidates (e.g., sports players) that will appear in the scene that they are going to broadcast; +- (2) broadcasters generate camera object groups by combining suitable multi-camera objects that capture candidate objects of interest among available camera objects located at the site where broadcasters want to broadcast; +- (3) broadcasters show videos or thumbnail images captured by each camera object group to the audiences; +- (4) an audience selects one camera object group that captures an object of interest that he or she is interested in among multi-camera object groups; +- (5) the audience also selects a main camera object among multi-camera objects in the selected camera object group; + +10 Rec. ITU-T Y.4412/F.747.8 (11/2015) + +- (6) the audience also selects a region of interest that includes an object of interest in the main camera object image; +- (7) video streaming server object streams and shows a video of the main camera object with sub-images (e.g., thumbnails) of other camera objects to the audience; +- (8) during the streaming, the audiences may switch the main camera object to another camera object if he or she wants to watch the video with a different camera angle; +- (9) after the object of interest selection, a video processing server object that is linked with the main camera object starts the video processing, such as automatic tracking of a selected object of interest in the main camera object frame by frame; +- (10) during the tracking process, the main camera object transmits a tracked position of the selected object of interest to the other camera objects by camera-to-camera transmission; +- (11) the other camera objects receive and calculate the position of the selected object of interest from the received tracked position in the image of the main camera object; +- (12) based on each calculated position of an object of interest in each camera object, the camera object control server object updates the component camera objects in each camera object group; +- (13) the process repeats step 4) to step 13) until the audiences or the broadcasters quit the current media service. + +Finally, each audience can enjoy personalized video media content that includes an object of interest and has a camera view that each audience wants to watch. + +### **I.2 Use case for an open screen service using multi-camera objects** + +Open screen service can be a use case of the ASM service. Open screen service is a service based on open platform to control various types of screens and to show content by sensing states (e.g., age and gender) and movement of a human being. Representative use cases of open screen service include digital signage and emergency service. For example, if a person is near a screen using open platform of open screen service, the screen can show an image or video media advertisement or an evacuation route to the person. + +In order to sense states and movement of human beings, multi-camera objects and camera control servers are mandatory for the open screen service. In the perspective of open screen service, the audience can be an advertiser or emergency service provider, and the object of interest can be a human being who is a customer of an advertiser. + +Figure I.2 explains use case for an open screen service using multi-camera objects: + +- (1) an object of interest (e.g., customer) moves to the vicinity of a screen (e.g., screen 1) equipped with a camera object (e.g., camera object 1). +- (2) The camera object (e.g., camera object 1) captures video data of the object of interest and then sends the captured video data to camera control server. +- (3) The camera control server sends information for tracking the object of interest to the camera object (e.g., camera object 1). +- (4) The camera control server sends the position information and captured video data to media server being owned by the audience (e.g., advertiser) and providing image or video media (e.g., advertisement) that the audience (e.g., advertiser) wants to provide for the object of interest (e.g., customer). + +- (5) The media server determines images or video media (e.g., advertisements) that the audience wants to provide for the object of interest (e.g., customer), and then provides the media to the screen (e.g., screen 1). Interaction between camera objects can include information for supporting the camera's tracking the object of interest. The information for tracking the object of interest can include position information for where the object of interest is located. + +![Diagram illustrating the use case for an open screen service using multi-camera objects, camera control server, and media server.](ff7ce44f3fdd51bae7b231f34df07c6a_img.jpg) + +The diagram illustrates a system architecture for an open screen service. It includes the following components and interactions: + +- Media server:** A server that provides media content to the screens. +- Audience (e.g., advertiser):** Represented by a building icon, it interacts with the Media server. +- Camera control server:** A server that manages the camera objects. +- Camera object 1, 2, 3:** Represented by camera icons, they interact with the Camera control server and the Media server. +- Screen 1, 2, 3:** Represented by TV icons, they display content. Screen 1 is red, Screen 2 and 3 show a soda bottle. +- Object of interest (e.g., customer):** Represented by a person icon, they are tracked by the camera objects. + +Numbered interactions (1-5) are shown: + +- A green arrow (1) points from Screen 2 to Screen 3. +- A black arrow (2) points from Camera object 2 to the Camera control server. +- A black arrow (3) points from the Media server to Camera object 1. +- A blue arrow (4) points from the Camera control server to the Media server. +- A red arrow (5) points from the Media server to Screen 1. + +Additional labels and connections: + +- A dashed purple double-headed arrow connects Camera object 1 and Camera object 2. +- A dashed purple double-headed arrow connects Camera object 2 and Camera object 3. +- A purple arrow points from the Object of interest to Camera object 1. +- A purple arrow points from the Object of interest to Camera object 2. +- A purple arrow points from the Object of interest to Camera object 3. +- A red arrow points from the Media server to Screen 1. +- A red arrow points from the Media server to Screen 2. +- A red arrow points from the Media server to Screen 3. + +Y.4412-F.747.8(15)\_FI.2 + +Diagram illustrating the use case for an open screen service using multi-camera objects, camera control server, and media server. + +**Figure I.2 – Use case for an open screen service using multi-camera objects, camera control server and media server** + +## Bibliography + +- [b-ITU-T Y.2002] Recommendation ITU-T Y.2002 (2009), *Overview of ubiquitous networking and of its support in NGN*. +- [b-ITU-T Y.4000] Recommendation ITU-T Y.4000/Y.2060 (2012), *Overview of the Internet of Things*. +- [b-ITU-T Y.4400] Recommendation ITU-T Y.4400/Y.2063 (2012), *Framework of Web of Things*. + + + +## ITU-T F-SERIES RECOMMENDATIONS NON-TELEPHONE TELECOMMUNICATION SERVICES + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | | +| Operating methods for the international public telegram service | F.1–F.19 | +| The gentex network | F.20–F.29 | +| Message switching | F.30–F.39 | +| The international telemesssage service | F.40–F.58 | +| The international telex service | F.59–F.89 | +| Statistics and publications on international telegraph services | F.90–F.99 | +| Scheduled and leased communication services | F.100–F.104 | +| Phototelegraph service | F.105–F.109 | +| MOBILE SERVICE | | +| Mobile services and multideestination satellite services | F.110–F.159 | +| TELEMATIC SERVICES | | +| Public facsimile service | F.160–F.199 | +| Teletex service | F.200–F.299 | +| Videotex service | F.300–F.349 | +| General provisions for telematic services | F.350–F.399 | +| MESSAGE HANDLING SERVICES | F.400–F.499 | +| DIRECTORY SERVICES | F.500–F.549 | +| DOCUMENT COMMUNICATION | | +| Document communication | F.550–F.579 | +| Programming communication interfaces | F.580–F.599 | +| DATA TRANSMISSION SERVICES | F.600–F.699 | +| AUDIOVISUAL SERVICES | F.700–F.799 | +| ISDN SERVICES | F.800–F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850–F.899 | +| HUMAN FACTORS | F.900–F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Terminals and subjective and objective assessment methods | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/Y/T-REC-H.621-200808-I_PDF-E/042733dc5e8e7f5f30b60adba3266cde_img.jpg b/marked/Y/T-REC-H.621-200808-I_PDF-E/042733dc5e8e7f5f30b60adba3266cde_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..fc196c09695fceafc87691871036ce9443e058e5 --- /dev/null +++ b/marked/Y/T-REC-H.621-200808-I_PDF-E/042733dc5e8e7f5f30b60adba3266cde_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:6d4430d3108328943895a5dfa7e54cd523bb56f1316f5fc7f92bda6f69be72f9 +size 66207 diff --git a/marked/Y/T-REC-H.621-200808-I_PDF-E/124c6108c63173818afb8ed49521e22d_img.jpg b/marked/Y/T-REC-H.621-200808-I_PDF-E/124c6108c63173818afb8ed49521e22d_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..5300aa9bff21175722629daf6f83f5b05a3b4d25 --- /dev/null +++ b/marked/Y/T-REC-H.621-200808-I_PDF-E/124c6108c63173818afb8ed49521e22d_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:f1f095bf23ca636e036d76caa51574de9e43c555943e10005a87b124510691b4 +size 48765 diff --git a/marked/Y/T-REC-H.621-200808-I_PDF-E/12de9b926df0384ec07702671827c9cd_img.jpg b/marked/Y/T-REC-H.621-200808-I_PDF-E/12de9b926df0384ec07702671827c9cd_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..da4a215cdb632eeeeaffa63e5c2525a75172a1ae --- /dev/null +++ b/marked/Y/T-REC-H.621-200808-I_PDF-E/12de9b926df0384ec07702671827c9cd_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:7c67c3a653aeb2ec2d305a0c04574932ac8d76d670216e9b4922eec9dc38a235 +size 49902 diff --git a/marked/Y/T-REC-H.621-200808-I_PDF-E/18442e4e239480f0c3c95b547aa8fde2_img.jpg b/marked/Y/T-REC-H.621-200808-I_PDF-E/18442e4e239480f0c3c95b547aa8fde2_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..c2f5fa522d589927710b26e3a17ebe6a65eefd9e --- /dev/null +++ b/marked/Y/T-REC-H.621-200808-I_PDF-E/18442e4e239480f0c3c95b547aa8fde2_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:d332c23ab065d60fab6d8bc2f5c3deedc9a59f54fc3402dcab8d82d379cda595 +size 88266 diff --git a/marked/Y/T-REC-H.621-200808-I_PDF-E/365b54f616aff249b4e6c0edafdcb9b3_img.jpg b/marked/Y/T-REC-H.621-200808-I_PDF-E/365b54f616aff249b4e6c0edafdcb9b3_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..8bd866a4c96e90825dc36018a212ca8ffb3061a2 --- /dev/null +++ b/marked/Y/T-REC-H.621-200808-I_PDF-E/365b54f616aff249b4e6c0edafdcb9b3_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:5b24e9016e66765bba4b611a4c2ca19ee9669d20d20a93f2ba7cf2e2efa66b0c +size 55320 diff --git a/marked/Y/T-REC-H.621-200808-I_PDF-E/410562339ce067fdc6fa41940c118658_img.jpg b/marked/Y/T-REC-H.621-200808-I_PDF-E/410562339ce067fdc6fa41940c118658_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..5c95bc027b751136d9d7a95ddef93a49741d34ff --- /dev/null +++ b/marked/Y/T-REC-H.621-200808-I_PDF-E/410562339ce067fdc6fa41940c118658_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:b2676bd9988184908576f0e6f3be42ee340d08dae9c18c67ad029682d996f084 +size 96380 diff --git a/marked/Y/T-REC-H.621-200808-I_PDF-E/5b8a756d9a71c35f17db8bcb90b438a3_img.jpg b/marked/Y/T-REC-H.621-200808-I_PDF-E/5b8a756d9a71c35f17db8bcb90b438a3_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..86e1a9dea0fa20500c47e66db635f2cb1222762d --- /dev/null +++ b/marked/Y/T-REC-H.621-200808-I_PDF-E/5b8a756d9a71c35f17db8bcb90b438a3_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:c3d660f005a31c32213d72a50ae565bfead96f1f4ce4ae30840855f2160570d4 +size 48721 diff --git a/marked/Y/T-REC-H.621-200808-I_PDF-E/5cab96b2d23174c25919840ecd50aa48_img.jpg b/marked/Y/T-REC-H.621-200808-I_PDF-E/5cab96b2d23174c25919840ecd50aa48_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..e6771be498824cb7d172e4df171aaddf6b41adbf --- /dev/null +++ b/marked/Y/T-REC-H.621-200808-I_PDF-E/5cab96b2d23174c25919840ecd50aa48_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:21139c1a05f94f9091f72c27af64ee71556273a26936198996841faa69506c28 +size 42605 diff --git a/marked/Y/T-REC-H.621-200808-I_PDF-E/75f0cb39f1cd165dfe4a6aa6c4d9388d_img.jpg b/marked/Y/T-REC-H.621-200808-I_PDF-E/75f0cb39f1cd165dfe4a6aa6c4d9388d_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..86575385c900e99f94197dc3d2c774cff56830d6 --- /dev/null +++ b/marked/Y/T-REC-H.621-200808-I_PDF-E/75f0cb39f1cd165dfe4a6aa6c4d9388d_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:91b85b0ebaba8e85dbb06f84adf38244fdebeb9d1628d5c4a21a1f6f6e20fa0b +size 83439 diff --git a/marked/Y/T-REC-H.621-200808-I_PDF-E/8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg b/marked/Y/T-REC-H.621-200808-I_PDF-E/8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..4273ae4e7225e4b0a649f11fec715e4a9677be3e --- /dev/null +++ b/marked/Y/T-REC-H.621-200808-I_PDF-E/8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:6064c4230f616135e0731564ef03ba962d3cb780abcae32818741f78f353ac0b +size 75733 diff --git a/marked/Y/T-REC-H.621-200808-I_PDF-E/a3dc41dc3df86ea68d266af2bf95cf5b_img.jpg b/marked/Y/T-REC-H.621-200808-I_PDF-E/a3dc41dc3df86ea68d266af2bf95cf5b_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..36cf51f8ba07e44aa7a4b009f3ba08eb2b570b1c --- /dev/null +++ b/marked/Y/T-REC-H.621-200808-I_PDF-E/a3dc41dc3df86ea68d266af2bf95cf5b_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:11780faeee75ba39ab4ed9de67a9e67abec0d9ba3068ebec661dea70c16e29d3 +size 4338 diff --git a/marked/Y/T-REC-H.621-200808-I_PDF-E/b3baf3a29b67c7425d2562ddbc52f0cc_img.jpg b/marked/Y/T-REC-H.621-200808-I_PDF-E/b3baf3a29b67c7425d2562ddbc52f0cc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..dbcc1052933b5c91adf959a91316b6c556166850 --- /dev/null +++ b/marked/Y/T-REC-H.621-200808-I_PDF-E/b3baf3a29b67c7425d2562ddbc52f0cc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:2ce1eb7ccf5d06cdd5d802708580431948b7eea6df031228e6ec8619c5a0bb28 +size 85766 diff --git a/marked/Y/T-REC-H.621-200808-I_PDF-E/e69b9188aa2c14ec6b21c83f711fef65_img.jpg b/marked/Y/T-REC-H.621-200808-I_PDF-E/e69b9188aa2c14ec6b21c83f711fef65_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..967b993cef1b6fd57b875918740c700cbf49b1fe --- /dev/null +++ b/marked/Y/T-REC-H.621-200808-I_PDF-E/e69b9188aa2c14ec6b21c83f711fef65_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:13f349d8bcbc9af8349ed2538b8a83e224bffe849475ae0c01b6e9d5f006f51f +size 48628 diff --git a/marked/Y/T-REC-H.642.1-201206-I_PDF-E/0bf9346902e9a3bdabf05ceacc1947f5_img.jpg b/marked/Y/T-REC-H.642.1-201206-I_PDF-E/0bf9346902e9a3bdabf05ceacc1947f5_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..1a957c182fb070955f935aef7b61cb4854054f1b --- /dev/null +++ b/marked/Y/T-REC-H.642.1-201206-I_PDF-E/0bf9346902e9a3bdabf05ceacc1947f5_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:4492fb63d4d85fff5c099537345ebf89f624eebea50db68bb55d0e5d33114e5d +size 45863 diff --git a/marked/Y/T-REC-H.642.1-201206-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg b/marked/Y/T-REC-H.642.1-201206-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..83de44cfa91ff96cd6d044185230bbdca1aff85e --- /dev/null +++ b/marked/Y/T-REC-H.642.1-201206-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:92c3c68bcdb95caa413d3d9a4747655489556a99ef57b3def4ad289d99ef7337 +size 6615 diff --git a/marked/Y/T-REC-H.642.1-201206-I_PDF-E/raw.md b/marked/Y/T-REC-H.642.1-201206-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..7bd6ad2bc832bf44abe7b99b460fd924a2b7e281 --- /dev/null +++ b/marked/Y/T-REC-H.642.1-201206-I_PDF-E/raw.md @@ -0,0 +1,516 @@ + + +I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +# H.642.1 + +(06/2012) + +SERIES H: AUDIOVISUAL AND MULTIMEDIA SYSTEMS + +Broadband, triple-play and advanced multimedia +services – Ubiquitous sensor network applications and +Internet of Things + +# --- **Multimedia information access triggered by tag-based identification – Identification scheme** + +Recommendation ITU-T H.642.1 + +![ITU logo](84a1d09fb489061482111515543b60dc_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with a red lightning bolt striking it, and the text "ITU" in blue, with "International Telecommunication Union" in smaller blue text below it. + +ITU logo + +## ITU-T H-SERIES RECOMMENDATIONS AUDIOVISUAL AND MULTIMEDIA SYSTEMS + +| | | +|-------------------------------------------------------------------------------|--------------------| +| CHARACTERISTICS OF VISUAL TELEPHONE SYSTEMS | H.100–H.199 | +| INFRASTRUCTURE OF AUDIOVISUAL SERVICES | | +| General | H.200–H.219 | +| Transmission multiplexing and synchronization | H.220–H.229 | +| Systems aspects | H.230–H.239 | +| Communication procedures | H.240–H.259 | +| Coding of moving video | H.260–H.279 | +| Related systems aspects | H.280–H.299 | +| Systems and terminal equipment for audiovisual services | H.300–H.349 | +| Directory services architecture for audiovisual and multimedia services | H.350–H.359 | +| Quality of service architecture for audiovisual and multimedia services | H.360–H.369 | +| Supplementary services for multimedia | H.450–H.499 | +| MOBILITY AND COLLABORATION PROCEDURES | | +| Overview of Mobility and Collaboration, definitions, protocols and procedures | H.500–H.509 | +| Mobility for H-Series multimedia systems and services | H.510–H.519 | +| Mobile multimedia collaboration applications and services | H.520–H.529 | +| Security for mobile multimedia systems and services | H.530–H.539 | +| Security for mobile multimedia collaboration applications and services | H.540–H.549 | +| Mobility interworking procedures | H.550–H.559 | +| Mobile multimedia collaboration inter-working procedures | H.560–H.569 | +| BROADBAND, TRIPLE-PLAY AND ADVANCED MULTIMEDIA SERVICES | | +| Broadband multimedia services over VDSL | H.610–H.619 | +| Advanced multimedia services and applications | H.620–H.629 | +| Ubiquitous sensor network applications and Internet of Things | H.640–H.649 | +| IPTV MULTIMEDIA SERVICES AND APPLICATIONS FOR IPTV | | +| General aspects | H.700–H.719 | +| IPTV terminal devices | H.720–H.729 | +| IPTV middleware | H.730–H.739 | +| IPTV application event handling | H.740–H.749 | +| IPTV metadata | H.750–H.759 | +| IPTV multimedia application frameworks | H.760–H.769 | +| IPTV service discovery up to consumption | H.770–H.779 | +| Digital Signage | H.780–H.789 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# **Recommendation ITU-T H.642.1** + +# **Multimedia information access triggered by tag-based identification – Identification scheme** + +## **Summary** + +Recommendation ITU-T H.642.1 defines an identification scheme for multimedia information access triggered by tag-based identification. Multimedia information associated with such an identifier can be retrieved using a resolution process. + +This Recommendation provides a framework for accommodating the legacy existing identification schemes together with the new identification scheme defined here using a pair of object identifiers for the identification scheme and identifier itself. + +## **History** + +| Edition | Recommendation | Approval | Study Group | +|---------|----------------|------------|-------------| +| 1.0 | ITU-T H.642.1 | 2012-06-29 | 16 | + +## **Keywords** + +Identification scheme, identifier. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2013 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | | Page | +|---|---------------------------------------------------------------------------------------------------------------------------|-------------| +| 1 | Scope ..... | 1 | +| 2 | References..... | 1 | +| 3 | Definitions ..... | 1 | +| | 3.1 Terms defined elsewhere..... | 1 | +| | 3.2 Terms defined in this Recommendation..... | 2 | +| 4 | Abbreviations and acronyms ..... | 2 | +| 5 | Conventions ..... | 3 | +| 6 | Concept of an identification scheme for multimedia information access triggered by tag-based identification..... | 3 | +| | 6.1 Overview ..... | 3 | +| | 6.2 Uniqueness of ID value ..... | 3 | +| 7 | ITU-T H.642 identification scheme for multimedia information access triggered by tag-based identification..... | 4 | +| | 7.1 Structure of an ITU-T H.642 identification scheme..... | 4 | +| | 7.2 First level code ..... | 5 | +| | 7.3 Second level code (2LC) ..... | 5 | +| | 7.4 Class ..... | 5 | +| | 7.5 Third level code (3LC) ..... | 5 | +| | 7.6 Fourth level code (4LC) ..... | 5 | +| | Appendix I – Survey on identification schemes ..... | 6 | +| | I.1 Introduction ..... | 6 | +| | I.2 Need for a generic identification scheme for multimedia information access triggered by tag-based identification..... | 6 | +| | I.3 Requirements on the identifier for multimedia information access triggered by tag-based identification..... | 6 | +| | I.4 Survey on existing identification schemes ..... | 7 | +| | Bibliography..... | 11 | + +## **Introduction** + +The identification scheme defined in this Recommendation provides a new method for accessing multimedia content without typing its address on a keyboard or inputting the name of objects and/or places of relevant information. This is a major communication service that uses an identifier in data carriers such as radio frequency identifications (RFIDs), smart cards and barcodes. + +The purpose of this Recommendation is to specify a new identification scheme to be used in applications and services where the existing identification schemes and their combinations cannot be used (see Appendix I for some examples). + +From the standpoint of compatibility and reusability of existing identifier schemes, this Recommendation provides a framework to support multiple identification schemes. In this framework, it is possible that multiple existing identification schemes together with the proposed new identification scheme can be used for identification where appropriate. Each identification scheme is identified by an object identifier (OID) according to [ITU-T X.660]. + +Clause 6 introduces the concept of multiple identification schemes for multimedia information access triggered by tag-based identification. + +Clause 7 specifies a new generic identification scheme for multimedia information access triggered by tag-based identification. + +Appendix I provides additional information which explains why a new generic identification scheme is needed. + +## Recommendation ITU-T H.642.1 + +# Multimedia information access triggered by tag-based identification – Identification scheme + +# 1 Scope + +This Recommendation defines an identification scheme for multimedia information access triggered by tag-based identification. This identification scheme is mainly used in the multimedia information system architecture defined in [ITU-T H.621]. It also satisfies the requirements defined in [ITU-T F.771]. + +This Recommendation does not define encoding rules to store the identifier value into data carriers such as barcode tags and RFID tags. When stored in a data carrier, the OID and identifier value shall be encoded according to the relevant international standards if such standards exist for the type of data carrier. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- [ITU-T F.771] Recommendation ITU-T F.771 (2008), *Service description and requirements for multimedia information access triggered by tag-based identification*. +- [ITU-T H.621] Recommendation ITU-T H.621 (2008), *Architecture of a system for multimedia information access triggered by tag-based identification*. +- [ITU-T H.642.2] Recommendation ITU-T H.642.2 (2012), *Multimedia information access triggered by tag-based identification – Registration procedures for identifiers*. +- [ITU-T X.660] Recommendation ITU-T X.660 (2011) | ISO/IEC 9834-1:2012, *Information technology – Procedures for the operation of object identifier registration authorities: General procedures and top arcs of the international object identifier tree*. +- [ITU-T X.668] Recommendation ITU-T X.668 (2008) | ISO/IEC 9834-9:2008, *Information technology – Open Systems Interconnection – Procedures for the operation of OSI Registration Authorities: Registration of object identifier arcs for applications and services using tag-based identification*. + +# 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 ID resolution** [ITU-T F.771]: A function to resolve an identifier into associated information. + +**3.1.2 multimedia information** [ITU-T F.771]: Digital information that uses multiple forms of information content and information processing, such as text, pictures, audio, video, three-dimensional panoramic pictures and digital maps, which informs or entertains users. + +**3.1.3 object identifier** [b-ITU-T X.680]: A globally unique value associated with an object to unambiguously identify it. + +### **3.2 Terms defined in this Recommendation** + +This Recommendation defines the following terms: + +**3.2.1 class**: Part of an identifier that defines the layout and interpretation of the following bit string inside the identifier, especially the length of the third level code (3LC) and fourth level code (4LC). + +**3.2.2 first level code (1LC)**: Part of the identifier that represents the identifier sub-blocks. + +**3.2.3 fourth level code (4LC)**: Part of the identifier which serializes individual multimedia information and services. + +**3.2.4 ITU-T H.642 identification scheme**: Name given to the identification scheme defined in this Recommendation. + +**3.2.5 identification scheme**: Definition and description of the structure of identifiers. + +**3.2.6 identifier value**: String of characters that represents the value of the identifier. + +**3.2.7 second level code (2LC)**: Part of the identifier assigned to ITU Member States. + +**3.2.8 third level code (3LC)**: Part of the identifier assigned to an RA that handles the allocation of the subspace to other organizations. + +# **4 Abbreviations and acronyms** + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|-------|--------------------------------------| +| 1LC | First Level Code | +| 2LC | Second Level Code | +| 3LC | Third Level Code | +| 4LC | Fourth Level Code | +| EPC | Electronic Product Code | +| GIAI | Global Individual Asset Identifier | +| GRAI | Global Returnable Asset Identifier | +| ID | Identifier | +| IP | Internet Protocol | +| ISBN | International Standard Book Number | +| ISSN | International Standard Serial Number | +| OID | Object Identifier | +| RA | Registration Authority | +| RFID | Radio Frequency Identification | +| SGLN | Serialized Global Location Number | +| SGTIN | Serialized Global Trade Item Number | + +| | | +|------|--------------------------------| +| SSCC | Serial Shipping Container Code | +| URL | Uniform Resource Locator | +| URN | Uniform Resource Name | +| UUID | Universally Unique Identifier | + +# 5 Conventions + +In this Recommendation, $xx_2$ denotes that number $xx$ is expressed as a binary (base-2) number. + +# 6 Concept of an identification scheme for multimedia information access triggered by tag-based identification + +### 6.1 Overview + +An identification scheme in this Recommendation is designed to discriminate multimedia information and services associated with "objects" or "places" of the real world in the architecture defined by [ITU-T H.621]. + +A data carrier such as an RFID tag which triggers access can be placed anywhere and its whereabouts is out of the scope of this Recommendation. + +### 6.2 Uniqueness of ID value + +Figure 1 gives an overview of the general approach to accommodate multiple identification schemes. Many different identification schemes can be used for multimedia information access triggered by tag-based identification. Each identification scheme should be identified by an object identifier (OID) under the arc $\{\text{joint-iso-itu-t}(2) \text{ tag-based}(27)\}$ as specified in [ITU-T X.668]. For example, in Figure 1, the top row indicates that Identification scheme 1 is identified by OID arch $\{\text{joint-iso-itu-t}(2) \text{ tag-based}(27) i_1\}$ . + +Identifier schemes which are widely used and already have an OID allocated to them (not under arc $\{\text{joint-iso-itu-t}(2) \text{ tag-based}(27)\}$ ) can continue to use that OID. In Figure 1, "Existing identification scheme 1", that has an OID value not under arc $\{\text{joint-iso-itu-t}(2) \text{ tag-based}(27)\}$ is identified by OID $\{x_1 y_1 z_1\}$ . + +For a given identifier scheme (identified by an OID), the uniqueness of identifier values is required to be managed by the organization which is allocating those values. That is, the uniqueness of identifier values should be managed by the registration authority (RA) for that identifier scheme with the cooperation of those who store identifiers into data carriers. + +![Diagram showing multiple identification schemes. It consists of four rows. The first row shows 'OID:2.27.i1' in a box, followed by a plus sign, and then 'Identification scheme 1' in a box. The second row shows a vertical ellipsis in the first column and a vertical ellipsis in the second column. The third row shows 'OID:2.27.im' in a box, followed by a plus sign, and then 'Identification scheme m' in a box. The fourth row shows a vertical ellipsis in the first column and a vertical ellipsis in the second column. The fifth row shows 'OID:x1.y1.z1' in a box, followed by a plus sign, and then 'Existing Identification scheme 1' in a box. The sixth row shows a vertical ellipsis in the first column and a vertical ellipsis in the second column. The seventh row shows 'OID:xN.yN.zN' in a box, followed by a plus sign, and then 'Existing Identification scheme N' in a box.](0bf9346902e9a3bdabf05ceacc1947f5_img.jpg) + +| | | | +|----------------------------------------------------|---|----------------------------------| +| OID:2.27.i 1 | + | Identification scheme 1 | +| ⋮ | | ⋮ | +| OID:2.27.i m | + | Identification scheme m | +| ⋮ | | ⋮ | +| OID:x 1 .y 1 .z 1 | + | Existing Identification scheme 1 | +| ⋮ | | ⋮ | +| OID:x N .y N .z N | + | Existing Identification scheme N | + +Diagram showing multiple identification schemes. It consists of four rows. The first row shows 'OID:2.27.i1' in a box, followed by a plus sign, and then 'Identification scheme 1' in a box. The second row shows a vertical ellipsis in the first column and a vertical ellipsis in the second column. The third row shows 'OID:2.27.im' in a box, followed by a plus sign, and then 'Identification scheme m' in a box. The fourth row shows a vertical ellipsis in the first column and a vertical ellipsis in the second column. The fifth row shows 'OID:x1.y1.z1' in a box, followed by a plus sign, and then 'Existing Identification scheme 1' in a box. The sixth row shows a vertical ellipsis in the first column and a vertical ellipsis in the second column. The seventh row shows 'OID:xN.yN.zN' in a box, followed by a plus sign, and then 'Existing Identification scheme N' in a box. + +Figure 1 – Multiple identification schemes + +# **7 ITU-T H.642 identification scheme for multimedia information access triggered by tag-based identification** + +### **7.1 Structure of an ITU-T H.642 identification scheme** + +The identification scheme defined in this Recommendation is called the ITU-T H.642 identification scheme. The ITU-T H.642 identification scheme consists of the fields: 'First Level Code' (1LC), 'Second Level Code' (2LC) and 'Class', followed by some of the elements ('Third Level Code' (3LC) and 'Fourth Level Code' (4LC)) as shown in Figure 2. + +| 1LC | 2LC | CLASS | 3LC / 4LC | | | | | | | | | | | | | | +|---------------------------------------------|------------------------------------------------------|-------------------|-----------|---------|-----|-----|-----|-----|-----|--|--|--|--|--|--|--| +| 4 bits | 16 bits | 4 bits | 8 bits | 16 bits | 16 | 16 | 16 | 16 | 16 | | | | | | | | +| 0001 2 | 16 bits | 0000 2 | Reserved | | | | | | | | | | | | | | +| | | 0001 2 | Reserved | | | | | | | | | | | | | | +| | | 0010 2 | Reserved | | | | | | | | | | | | | | +| | | 0011 2 | Reserved | | | | | | | | | | | | | | +| | | 0100 2 | Reserved | | | | | | | | | | | | | | +| | | 0101 2 | Reserved | | | | | | | | | | | | | | +| | | 0110 2 | Reserved | | | | | | | | | | | | | | +| | | 0111 2 | Reserved | | | | | | | | | | | | | | +| | | 1000 2 | Reserved | | | | | | | | | | | | | | +| | | 1001 2 | 3LC | 4LC | | | | | | | | | | | | | +| | | 1010 2 | 3LC | | 4LC | | | | | | | | | | | | +| | | 1011 2 | 3LC | | | 4LC | | | | | | | | | | | +| | | 1100 2 | 3LC | | | | 4LC | | | | | | | | | | +| | | 1101 2 | 3LC | | | | | 4LC | | | | | | | | | +| | | 1110 2 | 3LC | | | | | | 4LC | | | | | | | | +| | | 1111 2 | Reserved | | | | | | | | | | | | | | +| 0000 2 | Reserved for backward compatibility (see clause 7.2) | | | | | | | | | | | | | | | | +| 0010 2
~
1111 2 | Reserved for future use | | | | | | | | | | | | | | | | + +**Figure 2 – Structure of an identifier** + +**Table 1 – Field name and length** + +| Field name | Length | | | +|------------|---------------------------------------------------|---------------|---------------| +| 1LC | 4 bits | | | +| 2LC | 16 bits | | | +| CLASS | 4 bits | | | +| 3LC, 4LC | Variable length, but the sum of these is 104 bits | | | +| | Value of class | Length of 3LC | Length of 4LC | +| | 9 | 8 bits | 96 bits | +| | 10 | 24 bits | 80 bits | +| | 11 | 40 bits | 64 bits | +| | 12 | 56 bits | 48 bits | +| | 13 | 72 bits | 32 bits | +| | 14 | 88 bits | 16 bits | + +### **7.2 First level code** + +1LC is 4 bits long and represents the identifier of sub-blocks. It serves as version information. + +1LC from 00102 to 11112 are reserved for future use. + +Part of the identifier sub-block with 1LC of 00002 shall be reserved to avoid conflict with the 'unicode' identification scheme [b-uID]. + +### **7.3 Second level code (2LC)** + +2LC is 16 bits long and is assigned to ITU Member States as specified in [ITU-T H.642.2]. + +### **7.4 Class** + +Class indicates the layout of a particular identifier format. There are different formats that correspond to Class 9, 10..., 14 as shown on Figure 2 (Class 0, 1, 2..., 8, 15 are reserved for future use). + +### **7.5 Third level code (3LC)** + +The 3LC assignment is done by an entity that is assigned the 2LC of that subspace (see clause 7.3). A 3LC is assigned to an RA that handles the allocation of the subspace to other organizations. The subspace controlled by this RA is called the 3LC space. It has six different sizes from 16 bits to 96 bits by steps of 16 bits. + +3LC spaces are assumed to be managed by entities such as companies, associations, universities, schools, local governments, etc. + +### **7.6 Fourth level code (4LC)** + +4LC is a serialization number to identify individual multimedia information and services. + +# Appendix I + +## Survey on identification schemes + +(This appendix does not form an integral part of this Recommendation.) + +## I.1 Introduction + +The purpose of this appendix is to survey whether existing identification schemes (most of them being internationally standardized) satisfy the requirements found in [ITU-T F.771]. + +The currently existing schemes may not satisfy all the needs identified by [ITU-T F.771] that came later than the schemes themselves. The ITU-T H.642 identification scheme in this Recommendation is a complementary scheme to existing identification schemes. It is meant to fill the gaps left by existing schemes and identified by [ITU-T F.771] for particular classes of applications. It is complementary to existing schemes in this sense, and is not a competitor. This Recommendation outlines the framework to make these identification schemes co-exist in future applications to take advantage of all the existing schemes including the ITU-T H.642 identification scheme. + +## I.2 Need for a generic identification scheme for multimedia information access triggered by tag-based identification + +A generic identification scheme in this Recommendation is applicable to multimedia information and services associated with any kind of objects and places. Any systems for multimedia information access triggered by tag-based identification should implement the generic identification scheme defined in this Recommendation. + +## I.3 Requirements on the identifier for multimedia information access triggered by tag-based identification + +[ITU-T F.771] defines in clause 7.3 five requirements for identifiers for multimedia information access triggered by tag-based identification. The following gives clarification of each identifier requirement to stress that the identification scheme defined in this Recommendation satisfies these identifier requirements. + +- **ID-001: identifier is recommended to be used by different applications.** +Multimedia information access triggered by tag-based identification specifies a mechanism of information processing and communication, but no applications. The mechanism is proposed and recommended to be used by any application. In other words, it is for "general purpose" use. Also, the identifiers should be for general purposes too. This means, it is recommended to be used by different applications. Most identification schemes can be used for many applications, so almost every identification scheme satisfies this requirement. +- **ID-002: identifier is required to be assigned for real-world entities such as physical/logical objects, persons and places.** +"Tag-based identification" deals with every type of real-world entity e.g. tangible objects (items), persons and places because all of these can be targets of tag-based identification. (Although "people" is mentioned here, this Recommendation does not attempt to define an identifier for persons). In some applications, the information service is triggered by some tangible objects (items), persons or places. Thus, identifiers must be assignable to tangible objects, logical objects, people and places. It is important to note that many application target areas do not have an applicable international standard identification scheme. For example, locations with meanings, vegetables, fish, meat, houses, roads, buildings, bridges, boats, art items, posters and so on, do not have proper identification schemes based on an + +international standard. This Recommendation is meant for such wider areas which lack any previous standard ID scheme. + +- **ID-003: identifier is required to be issuable by any organization such as companies, non-profit organizations, governments and individual users.** + +- ID-003 is a requirement for the governance of identification schemes. To satisfy this requirement, for example, even an individual without any corporate affiliation should be able to obtain identifiers, and identifiers must be allocated at a low enough cost. For example, if an identification scheme has a short company code bit field, and it is too short to be used by all the companies in the country or in the world, it does not satisfy this requirement. If the company code cannot be assigned to non-company organizations such as governments, NPOs, small businesses, schools and individuals, it does not satisfy this requirement. The governance of this Recommendation should satisfy this requirement. + +- **ID-004: identifier is required to be globally unique so that the multimedia information access triggered by the identifier is globally available.** + +Essentially, the identification scheme proposed must be a globally unique numbering system. When the same identifier is assigned to two different entities, confusion arises. However, some identification schemes do not follow this principle entirely. For example, an IP address system has a private address subspace in its numbering space, such as "192.168.1.1". Everyone can assign the private address to the network interfaces of his/her own networked machines. Some supply chain management (SCM) identification schemes have an "in-house ID code area", which can be used by shops or factories freely, thus the code area is not globally unique. In [b-ITU-T X.667], identifiers are generated automatically by a standard algorithm and procedure, so each identifier is assured to be almost globally unique. However, in theory, there is a small possibility of collisions when random number generators are used. Additionally, there may be bugs in the identifier generating software, and some unauthorised people may intentionally issue duplicate identifiers. Therefore, [b-ITU-T X.667] does not fully satisfy this requirement. The governance of this Recommendation is meant to satisfy this requirement. + +- **ID-005: multiple identifier schemes are required to be supported.** + +This is an important requirement to accommodate both the existing and the yet-to-appear future identification schemes. + +Among the requirements outlined above, ID-005 is not a requirement for the identification scheme itself, but for the system that utilizes identifiers. Therefore, this requirement is excluded from the use case analysis. ID-001 is also excluded from the use case analysis because all the target identification schemes listed below satisfy this requirement. + +## **I.4 Survey on existing identification schemes** + +#### **I.4.1 Existing identification schemes** + +To make this use case analysis comprehensive, widely-used existing identification schemes from a wide range of application areas were studied. + +##### **I.4.1.1 EPC** + +The electronic product code (EPC) is a family of identification schemes proposed by EPCglobal. It is currently one of the most widely used identification schemes in the field of supply chain management, even though it is not a *de jure* international standard. It is designed to be used in a low-cost way for tracking goods using RFID technology, to meet the needs of various industries, to identify each item manufactured (unlike barcode systems), and to guarantee uniqueness for all EPC-compliant tags. This implies that the initial intention of EPC is to identify products manufactured by using RFID-based tags. + +It contains a serialized global trade item number (SGTIN), a serial shipping container code (SSCC), a serialized global location number (SGLN), a global returnable asset identifier (GRAI) and a global individual asset identifier (GIAI). + +##### **I.4.1.2 ISO/IEC 15459-x** + +[b-ISO/IEC 15459-x] is an identification scheme designed for supply chain management because the original intended application of this identification scheme is for a supply chain management system. + +##### **I.4.1.3 ISO/IEC 6709** + +[b-ISO/IEC 6709] is an international standard representation of latitude, longitude and altitude for (fixed) geographic point locations. It is used by many GIS applications. But other kinds of ID-based applications such as a supply chain management system, which is intended for the identification of moving objects, cannot use this identification scheme. (It is impractical to replace identifiers whenever objects change their locations. We need a separation of the identifier value and the location information. The multiple identification schemes in [ITU-T H.621] would be effective here). + +##### **I.4.1.4 ISO 2108 International standard book number** + +The international standard book number (ISBN) is a numbering scheme for the identification of books. + +##### **I.4.1.5 ISO 3297 International standard serial number** + +The international standard serial number (ISSN) is a numbering scheme for the identification of serial publications such as newspapers, magazines, journals and annually published books globally. + +##### **I.4.1.6 Universally unique identifier** + +The universally unique identifier (UUID) in [b-ITU-T X.667] is an identification scheme designed for identifying information or components in the distributed systems without the assumption of any management systems of identifiers. One of the most famous implementation of UUID is Microsoft's GUID. + +##### **I.4.1.7 ISO/IEC 15963** + +[b-ISO/IEC 15963] is an identification scheme designed for RFID tags and mainly used for supply chain management. Since this identification scheme is designed only for RFID tags, it cannot be used for applications that require other kinds of ID tags such as a printing code. + +##### **I.4.1.8 ISO/IEC 11784** + +[b-ISO/IEC 11784] is an identification scheme designed for identifying animals. + +NOTE – All of the above identification schemes other than EPC are *de jure* international standards, and also note that EPC is widely used. + +#### **I.4.2 Analysis** + +Surveys on existing identification schemes are in Table I.1. For comparison, the ITU-T H.642 identification scheme is also included in this analysis. + +**Table I.1 – Analysis of existing identification schemes** + +| ID schemes | ID-002 | ID-003 | ID-004 | +|-------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------| +| EPC | Most identifiers are mainly assigned to objects, but not to logical objects. SSCC can be assigned for shipping containers and SGLN can be assigned only for locations. | Registered issuing agencies may issue identifiers and a hierarchical structure of issuing agencies is provided. | Each identifier is assured to be globally unique. | +| ISO/IEC 15459-x | Identifiers are mainly assigned for objects, but not places. Since this identification scheme is designed for ID tags, it is impossible to assign the identifier to any logical object. | Registered issuing agencies may issue identifiers and a hierarchical structure of issuing agencies is provided. | Each identifier is assured to be globally unique. | +| ISO 6709 | Identifiers are assigned for geographic point locations. This identifier cannot be assigned to any objects that move around. | It is a representation for identifying geographic point locations, thus no one can issue the identifiers. | Each identifier is assured to be globally unique. | +| ISBN | ISBN numbers are assigned only for books and physical publications. ISBN numbers are not assignable for any logical objects and other physical objects. | Only affiliated organizations (sometimes national organizations) that manage books in the region or country may issue the ISBN numbers. | Identifiers are assured to be globally unique. | +| ISSN | ISSN numbers are assigned only for serial publications. ISSN numbers are not assignable for any other logical or physical objects. | Only affiliated organizations (sometimes national organizations) that manage serial publications in the region or country may issue the ISSN numbers. | Identifiers are assured to be globally unique. | +| UUID | Identifiers can be assigned for everything that can be identified. | Individual users or programs may issue identifiers. Since central coordination is difficult in this identification scheme, it is not suitable for organizations that want to control issuance of identifiers from the fixed numbering space that can freely be managed by the organization to hierarchically manage products. | Each identifier is almost assured to be globally unique, but there is small possibility of collisions (except if the UUID is registered as an OID). | + +**Table I.1 – Analysis of existing identification schemes** + +| ID schemes | ID-002 | ID-003 | ID-004 | +|-----------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------| +| ISO/IEC 15963 | Identifiers are mainly assigned for objects, but not places. Since this identification scheme is designed for RFID tags, it is impossible to assign the identifier to any logical objects. | This identifier is always written into RFID tags when a tag chip manufacturer produces an RFID tag. Only tag chip manufacturers can issues this identifier. | Each identifier is assured to be globally unique. | +| ISO/IEC 11784 | Identifiers are assigned only for animals. | Registered issuing agencies may issue identifiers and a hierarchical structure of issuing agencies is provided. | Each identifier is assured to be globally unique. | +| ITU-T H.642 identification scheme | An ITU-T H.642 identifier can be assigned for multimedia information and services associated with any object or place. | Registered issuing agencies may issue identifiers and a hierarchical structure of issuing agencies is provided. | Each identifier is assured to be globally unique. | + +#### I.4.3 Summarized analysis + +Table I.2 summarizes the information given in the preceding clauses. According to this investigation, it is considered that no existing identification scheme other than the ITU-T H.642 identification scheme satisfies all the requirements described in [ITU-T F.771]. + +**Table I.2 – Summary of analysis** + +| | ID-002 | ID-003 | ID-004 | +|---------------------------------------------------------|--------|--------|--------| +| EPC | U | S | S | +| ISO/IEC 15459-x | U | S | S | +| ISO 6709 | U | U | S | +| ISBN | U | S | S | +| ISSN | U | S | S | +| UUID | S | U | P | +| ISO/IEC 15963 | U | P | S | +| ISO/IEC 11784 | U | S | S | +| ITU-T H.642 identification scheme | S | S | S | +| S: satisfied, U: unsatisfied, P: Not strictly satisfied | | | | + +## Bibliography + +- [b-ITU-T X.667] Recommendation ITU-T X.667 (2008) | ISO/IEC 9834-8:2008, *Information technology – Open Systems Interconnection – Procedures for the operation of OSI Registration Authorities: Generation and registration of Universally Unique Identifiers (UUIDs) and their use as ASN.1 object identifier components*. +- [b-ITU-T X.680] Recommendation ITU-T X.680 (2002) | ISO/IEC 8824-1:2002, *Information technology – Abstract Syntax Notation One (ASN.1): Specification of basic notation*. +- [b-ISO 2108] ISO 2108 (2005), *Information and documentation – International standard book number (ISBN)*. +- [b-ISO 3297] ISO 3297 (2007), *Information and documentation – International standard serial number (ISSN)*. +- [b-ISO 6709] ISO 6709 (2008), *Standard representation of geographic point location by coordinates*. +- [b-ISO 11784] ISO/IEC 11784 (1996), *Radio frequency identification of animals – Code structure*. +- [b-ISO/IEC 15459-x] ISO/IEC 15459-x, *Information technology – Unique identifiers*. +- [b-ISO/IEC 15963] ISO/IEC 15963 (2009), *Information technology – Radio frequency identification for item management – Unique identification for RF tags*. +- [b-uID] uID (2009), *Ubiquitous Code: ucode*, uID center, Version 1.A0.10. + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|---------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Terminals and subjective and objective assessment methods | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/Y/T-REC-Y.1001-200011-I_PDF-E/042733dc5e8e7f5f30b60adba3266cde_img.jpg b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/042733dc5e8e7f5f30b60adba3266cde_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..bb99702855791430b131f8a382bf4c81d33d0e28 --- /dev/null +++ b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/042733dc5e8e7f5f30b60adba3266cde_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:80fb3dd8f50140b399fdcaeee440f86c47cd0ed3299dd40f12b71f6ef4fd1443 +size 85675 diff --git a/marked/Y/T-REC-Y.1001-200011-I_PDF-E/0f985b39edc1d52ba3600c438bc8f0a5_img.jpg b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/0f985b39edc1d52ba3600c438bc8f0a5_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..47ffeeda7d75d2c154b7568d6c8087da2ad5c4b4 --- /dev/null +++ b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/0f985b39edc1d52ba3600c438bc8f0a5_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:bff5f93dabf60ea791a70e89a4d86f23d80363035812843e716c05650f086e9b +size 84227 diff --git a/marked/Y/T-REC-Y.1001-200011-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..104a57fbd03964ffd2520508b2be42e03343d20f --- /dev/null +++ b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:f2468dfa77e8d32611a5fe8a2ebb904676994eeb54463226fd865698560c960c +size 8232 diff --git a/marked/Y/T-REC-Y.1001-200011-I_PDF-E/3ae74a33759ae31781f484406db4feed_img.jpg b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/3ae74a33759ae31781f484406db4feed_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..2fff57d6ed91f2785bde076d28ea577f56a74f56 --- /dev/null +++ b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/3ae74a33759ae31781f484406db4feed_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:c8e9c43940f06bbcc0018bed943121f74dbb06ee3268d7392501bd1753df6f6d +size 71830 diff --git a/marked/Y/T-REC-Y.1001-200011-I_PDF-E/474a819357587e34949a3e110ff19b30_img.jpg b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/474a819357587e34949a3e110ff19b30_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..139da2d10dc90267af237ec74eaca84f286027e5 --- /dev/null +++ b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/474a819357587e34949a3e110ff19b30_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:068eebaab17f7c620a9372a8456bb04576c9ed15cdf1ae631f55f6f1ffecaf35 +size 59082 diff --git a/marked/Y/T-REC-Y.1001-200011-I_PDF-E/5132b3a97ac70fe4765c1e07e66b72b3_img.jpg b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/5132b3a97ac70fe4765c1e07e66b72b3_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..3d9097491f4d8bf31f10e139cf6f623fefd44fc6 --- /dev/null +++ b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/5132b3a97ac70fe4765c1e07e66b72b3_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:cf0a1fd759bfead289615c718cd26d2b0e001152a94bb5a68227538bc89c15c8 +size 39142 diff --git a/marked/Y/T-REC-Y.1001-200011-I_PDF-E/5b8a756d9a71c35f17db8bcb90b438a3_img.jpg b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/5b8a756d9a71c35f17db8bcb90b438a3_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..fb6e14aa044d90ff4d2c1221d43bb73e67cf34ac --- /dev/null +++ b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/5b8a756d9a71c35f17db8bcb90b438a3_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:10d4f3e4b62d85f57d390f19acf368261916d1a2854a2a14c26e612ea7a6e6d4 +size 73109 diff --git a/marked/Y/T-REC-Y.1001-200011-I_PDF-E/69b7bd65e85cdef6fdd7fb0a8194257c_img.jpg b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/69b7bd65e85cdef6fdd7fb0a8194257c_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..08ebfc6e98d378f10bdb02f79ced28516b0fdc62 --- /dev/null +++ b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/69b7bd65e85cdef6fdd7fb0a8194257c_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:86af83847461b8dc1e33a2b6640b78495972454f05ce8b82a4d307cd4a865759 +size 59717 diff --git a/marked/Y/T-REC-Y.1001-200011-I_PDF-E/7133ccf78043568ca62ecbcd43628a4a_img.jpg b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/7133ccf78043568ca62ecbcd43628a4a_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..1507ff3c007febb49e8a1d6e533ef7ff683eca51 --- /dev/null +++ b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/7133ccf78043568ca62ecbcd43628a4a_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:4f350af6cecb4dea546ae8292ea302b6b994aeb5ce1415e67a3f19377c1ad080 +size 54551 diff --git a/marked/Y/T-REC-Y.1001-200011-I_PDF-E/83852ec55d4802521a727926336bedab_img.jpg b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/83852ec55d4802521a727926336bedab_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..c644716f419a1846a1cd9aee79b7ef14cdbe4b77 --- /dev/null +++ b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/83852ec55d4802521a727926336bedab_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:80c5bd931f223e9084f603de2e1447fd7e7ee72984e91c7bd33de8e38485fa89 +size 51208 diff --git a/marked/Y/T-REC-Y.1001-200011-I_PDF-E/8c348bf9c2c81b018017ae1d19506a9a_img.jpg b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/8c348bf9c2c81b018017ae1d19506a9a_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..6ea957945d3397c5186d31451556ab3e48bead51 --- /dev/null +++ b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/8c348bf9c2c81b018017ae1d19506a9a_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:bf2e04dcbaddfabf557039b61f650f87dfe3f6a302580dff7cb7919fbb86f2df +size 77143 diff --git a/marked/Y/T-REC-Y.1001-200011-I_PDF-E/8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..5522f7312409fde9f4ed1751210f0326705ff97b --- /dev/null +++ b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:c2d4c0c3bc531217e6008ae435956f699de12b143e7c9ecc0e720404328e04b0 +size 48149 diff --git a/marked/Y/T-REC-Y.1001-200011-I_PDF-E/a0739aaf13fa5a632d4faa830f6b2708_img.jpg b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/a0739aaf13fa5a632d4faa830f6b2708_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..1eff83b356ebe59d7b765ecb1c7e90aac85c7f8c --- /dev/null +++ b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/a0739aaf13fa5a632d4faa830f6b2708_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:9ce4a9b5145972bfe9919f729e23519093c3cc265c1717952a2d58ac279c1d28 +size 54805 diff --git a/marked/Y/T-REC-Y.1001-200011-I_PDF-E/b8661c6c54f72ecc7ff6cb05e47b2891_img.jpg b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/b8661c6c54f72ecc7ff6cb05e47b2891_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..49fb2cd20cd056d79cd71a5da8373dd1355fe5dc --- /dev/null +++ b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/b8661c6c54f72ecc7ff6cb05e47b2891_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:ee2512e6912b283176432b3767ab9ffb4f891febc7e076fb17f4ef9352e41b8d +size 48779 diff --git a/marked/Y/T-REC-Y.1001-200011-I_PDF-E/dfe556fea00682b09a59427aaf72051c_img.jpg b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/dfe556fea00682b09a59427aaf72051c_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..981799ec5f25a33bd8b12de72300a28df92a8d42 --- /dev/null +++ b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/dfe556fea00682b09a59427aaf72051c_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:bec79111eeac310f6ed592e7e6e0d24253073b991bb8c264be456c30a88e8550 +size 39709 diff --git a/marked/Y/T-REC-Y.1001-200011-I_PDF-E/e9314c83043183351ed74908e9bf2f90_img.jpg b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/e9314c83043183351ed74908e9bf2f90_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..f1963f52002ab14b08bac1cddd59f307645d36eb --- /dev/null +++ b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/e9314c83043183351ed74908e9bf2f90_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:f3cf06bb1992b3488dc106f3ef40fc0873a75cad682763e114f795b242c8e5e5 +size 73908 diff --git a/marked/Y/T-REC-Y.1001-200011-I_PDF-E/eefe19c5e14dc4d6c316b7f7fbb7d7d7_img.jpg b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/eefe19c5e14dc4d6c316b7f7fbb7d7d7_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..120334f6a66a29651a46f9de8bb0599638e99ca4 --- /dev/null +++ b/marked/Y/T-REC-Y.1001-200011-I_PDF-E/eefe19c5e14dc4d6c316b7f7fbb7d7d7_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:56e99b5530ff82b7f4d49b186f2a4e5b8f2902bb3ff1be665ae6b08d59c6f44a +size 101249 diff --git a/marked/Y/T-REC-Y.1251-200208-I_PDF-E/053f1077d592e6622cd21dc4bb4cb366_img.jpg b/marked/Y/T-REC-Y.1251-200208-I_PDF-E/053f1077d592e6622cd21dc4bb4cb366_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..98cc93adaeead4f0a1c4d2200996c610d146d3f6 --- /dev/null +++ b/marked/Y/T-REC-Y.1251-200208-I_PDF-E/053f1077d592e6622cd21dc4bb4cb366_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:3ce77294be03ac2a0046b32b44a5e528b5bd99a21382abfbd6729171b16b9cb1 +size 55633 diff --git a/marked/Y/T-REC-Y.1251-200208-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/Y/T-REC-Y.1251-200208-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..939eb6a57fac47a375526475ba6c31bf67e08b30 --- /dev/null +++ b/marked/Y/T-REC-Y.1251-200208-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:52a289bbb49d106b16f646b5050f62e5c7cbe1bb201f8c767547c3039abbf359 +size 8245 diff --git a/marked/Y/T-REC-Y.1251-200208-I_PDF-E/367926125450c2bc3f4bdca9d59a62ba_img.jpg b/marked/Y/T-REC-Y.1251-200208-I_PDF-E/367926125450c2bc3f4bdca9d59a62ba_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..bb54249e296b4d30086c26080d215cc68a9a2c18 --- /dev/null +++ b/marked/Y/T-REC-Y.1251-200208-I_PDF-E/367926125450c2bc3f4bdca9d59a62ba_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:cb8ca4757ca78ba880924c790df9fcb22d087ab158b7592b465c35b67c2b322b +size 13273 diff --git a/marked/Y/T-REC-Y.1251-200208-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg b/marked/Y/T-REC-Y.1251-200208-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..334e07b58598c439dc55821b3a610bba3826c916 --- /dev/null +++ b/marked/Y/T-REC-Y.1251-200208-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:fabb00ff4d79cbb4b6134fe923b1142cb954eca6fbd5e2ee3d4a324bf432b0c7 +size 55511 diff --git a/marked/Y/T-REC-Y.1251-200208-I_PDF-E/5e92d9e8e9ce204e405bff2367f88176_img.jpg b/marked/Y/T-REC-Y.1251-200208-I_PDF-E/5e92d9e8e9ce204e405bff2367f88176_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..c5dbeb26e7b76a851b5891fbfa5c2c8511efcda9 --- /dev/null +++ b/marked/Y/T-REC-Y.1251-200208-I_PDF-E/5e92d9e8e9ce204e405bff2367f88176_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:fc7423abd7bc572d9ed1c9e993ecf6686d90231cd6af3a676910eb27f88b3f97 +size 49424 diff --git a/marked/Y/T-REC-Y.1251-200208-I_PDF-E/731f533b0599c8e42a063f06e4332045_img.jpg b/marked/Y/T-REC-Y.1251-200208-I_PDF-E/731f533b0599c8e42a063f06e4332045_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..64d20de52726aaf72ab94b545bb03496bff032af --- /dev/null +++ b/marked/Y/T-REC-Y.1251-200208-I_PDF-E/731f533b0599c8e42a063f06e4332045_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:5850c9037044941f570c017fca0f6258b85dd71cea61dda30855026c092a4660 +size 17475 diff --git a/marked/Y/T-REC-Y.1251-200208-I_PDF-E/97fe9069356cc2a84e8e70673e405958_img.jpg b/marked/Y/T-REC-Y.1251-200208-I_PDF-E/97fe9069356cc2a84e8e70673e405958_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..e888fe46f3a9d00954426df87ac82ffdaab58675 --- /dev/null +++ b/marked/Y/T-REC-Y.1251-200208-I_PDF-E/97fe9069356cc2a84e8e70673e405958_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:d851d5a276336c2cfa57348a057942f61350a45e91eb71cb4246253afaca63ee +size 8836 diff --git a/marked/Y/T-REC-Y.1251-200208-I_PDF-E/a33da0f14e456f92539ce3e9b7d81f9a_img.jpg b/marked/Y/T-REC-Y.1251-200208-I_PDF-E/a33da0f14e456f92539ce3e9b7d81f9a_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..812a842c943ac678772130620eaf5f5dd7ba5346 --- /dev/null +++ b/marked/Y/T-REC-Y.1251-200208-I_PDF-E/a33da0f14e456f92539ce3e9b7d81f9a_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:b28f036ab9b6236f7fcb252541c0d395547ee248afc521505f0cd9bb018b5e1a +size 66408 diff --git a/marked/Y/T-REC-Y.1251-200208-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg b/marked/Y/T-REC-Y.1251-200208-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..e52597eb0a74d3803a0474959f6d466409314705 --- /dev/null +++ b/marked/Y/T-REC-Y.1251-200208-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:2a6b1318b8daedd287cca96dcfb0f3c6e7d661bb9b16ee64475302882814668a +size 51092 diff --git a/marked/Y/T-REC-Y.1251-200208-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg b/marked/Y/T-REC-Y.1251-200208-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..08efce85c7ef43d9c4baa7d21a9bba42b72a0d12 --- /dev/null +++ b/marked/Y/T-REC-Y.1251-200208-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:9ff73609f7b1f0ebaffb557927b0bf81760d4cdc2ef8ab4b8589b483182acd0b +size 52698 diff --git a/marked/Y/T-REC-Y.1251-200208-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg b/marked/Y/T-REC-Y.1251-200208-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..f2cd48e257bafddc6baca263765140030a1bf5bf --- /dev/null +++ b/marked/Y/T-REC-Y.1251-200208-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:1476ea3ee056622c8a6e721bbb1345f4c3db90f20dcbd0ccce2a23a7cb9b8da5 +size 15892 diff --git a/marked/Y/T-REC-Y.1251-200208-I_PDF-E/raw.md b/marked/Y/T-REC-Y.1251-200208-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..a393c117db0f5415f18e68d4feec4881eb10aa5d --- /dev/null +++ b/marked/Y/T-REC-Y.1251-200208-I_PDF-E/raw.md @@ -0,0 +1,381 @@ + + +![ITU logo: a globe with the letters ITU inside, and a lightning bolt striking the globe.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU inside, and a lightning bolt striking the globe. + +INTERNATIONAL TELECOMMUNICATION UNION + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**Y.1251** + +(08/2002) + +SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE +AND INTERNET PROTOCOL ASPECTS + +Internet protocol aspects – Architecture, access, network +capabilities and resource management + +# --- **General architectural model for interworking** + +ITU-T Recommendation Y.1251 + +--- + +## ITU-T Y-SERIES RECOMMENDATIONS GLOBAL INFORMATION INFRASTRUCTURE AND INTERNET PROTOCOL ASPECTS + +| | | +|---------------------------------------------------------------------------|----------------------| +| GLOBAL INFORMATION INFRASTRUCTURE | | +| General | Y.100–Y.199 | +| Services, applications and middleware | Y.200–Y.299 | +| Network aspects | Y.300–Y.399 | +| Interfaces and protocols | Y.400–Y.499 | +| Numbering, addressing and naming | Y.500–Y.599 | +| Operation, administration and maintenance | Y.600–Y.699 | +| Security | Y.700–Y.799 | +| Performances | Y.800–Y.899 | +| INTERNET PROTOCOL ASPECTS | | +| General | Y.1000–Y.1099 | +| Services and applications | Y.1100–Y.1199 | +| Architecture, access, network capabilities and resource management | Y.1200–Y.1299 | +| Transport | Y.1300–Y.1399 | +| Interworking | Y.1400–Y.1499 | +| Quality of service and network performance | Y.1500–Y.1599 | +| Signalling | Y.1600–Y.1699 | +| Operation, administration and maintenance | Y.1700–Y.1799 | +| Charging | Y.1800–Y.1899 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# **ITU-T Recommendation Y.1251** + +# **General architectural model for interworking** + +## **Summary** + +This Recommendation specifies a general architectural model for interworking that can be used to analyze, categorize and describe cases of interworking between networks. + +Two interworking methods are identified, namely **Service Interworking** and **Network Interworking**. + +## **Source** + +ITU-T Recommendation Y.1251 was prepared by ITU-T Study Group 13 (2001-2004) and approved under the WTSA Resolution 1 procedure on 13 August 2002. + +## **Keywords** + +Interworking, Network Interworking, Service Interworking. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database. + +© ITU 2002 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## CONTENTS + +| | Page | +|----------------------------------------------------------------------------------|-------------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 4 Abbreviations..... | 2 | +| 5 Interworking – General considerations..... | 2 | +| 5.1 The problem space..... | 2 | +| 5.2 Possible solutions ..... | 2 | +| 6 Protocol adjacency relationships ..... | 4 | +| 6.1 Layering principle ..... | 4 | +| 6.2 Peering principle..... | 5 | +| 7 Generic interworking model..... | 5 | +| 8 Application of the model to service interworking and network interworking..... | 6 | +| 8.1 Service interworking ..... | 6 | +| 8.2 Network interworking ..... | 7 | +| 9 Related principles ..... | 9 | + + + +# ITU-T Recommendation Y.1251 + +# General architectural model for interworking + +# 1 Scope + +This Recommendation specifies a generic interworking model that can be used to analyze, categorize and describe cases of interworking between networks. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- [1] ITU-T Recommendation I.510 (1993), *Definitions and general principles for ISDN interworking*. +- [2] ITU-T Recommendation G.805 (2000), *Generic functional architecture of transport networks*. +- [3] ITU-T Recommendation Y.1001 (2000), *IP framework – A framework for convergence of telecommunications network and IP network technologies*. +- [4] ITU-T Recommendation Y.1401 (2000), *General requirements for interworking with Internet Protocol (IP)-based networks*. + +## 3 Definitions + +For the purposes of this Recommendation the following definitions are employed. Consistency with definitions in other Recommendations has been taken into account and is noted where appropriate. + +**3.1 interworking:** The term interworking is used to express interactions between networks, between end systems, or between parts thereof, with the aim of providing a functional entity capable of supporting an end-to-end communication. The interactions required to provide a functional entity rely on functions and on the means to select these functions. + +NOTE – This definition is identical to that given in ITU-T Rec. I.510, see [1]. + +**3.2 service interworking:** In service interworking, the Interworking Function (IWF) of Figure 4 terminates the protocol used in network 1 and translates (i.e., mapping) the Protocol Control Information (PCI) to the PCI of the protocol used in network 2 for User, Control and Management Plane functions to the extent possible. In general, since not all functions may be supported in one or other of the networks, the translation of PCI may be partial or non-existent. However, this should not result in any loss of user data since the payload is not affected by PCI conversion at the service interworking IWF. + +NOTE – This definition is identical to that given in ITU-T Rec. Y.1401, see [4]. + +**3.3 network interworking:** In network interworking, the PCI of the protocol used in network 1 and network 2 and the payload information are transferred transparently by an IWF of Figure 4. Typically the IWF encapsulates (known as tunnelling in some specifications) the information which is transmitted by means of an adaptation function and transfers it transparently to the other network. + +NOTE – This definition is identical to that given in ITU-T Rec. Y.1401, see [4]. + +**3.4 adaptation function:** A processing function which adapts the client layer network characteristic information into a form suitable for transport over a trail1 in the server layer network. + +NOTE – This definition is taken from ITU-T Rec. G.805, see [2]. + +## 4 Abbreviations + +This Recommendation uses the following abbreviations: + +IP      Internet Protocol +IWF    Interworking Function +IWU    Interworking Unit +PCI    Protocol Control Information + +## 5 Interworking – General considerations + +### 5.1 The problem space + +The objective of interworking is to provide end-to-end connectivity across two separate networks, N1 and N2, which cannot be directly interconnected due to the deployment of different protocols in each of these networks. + +Simply, the problem to be solved is illustrated in Figure 1. + +![Diagram illustrating the interworking problem between Network 1 and Network 2.](731f533b0599c8e42a063f06e4332045_img.jpg) + +The diagram shows two ovals representing 'Network 1' and 'Network 2'. Above them is a double-headed horizontal arrow with a question mark '?' in the center. Below the ovals, the text 'N1 stack not equal N2 stack' is written. The identifier 'Y.1251\_F01' is located at the bottom right of the diagram. + +Diagram illustrating the interworking problem between Network 1 and Network 2. + +**Figure 1/Y.1251 – The interworking problem** + +The lack of direct interconnectivity will arise when the protocol stacks in Network 1 (N1) are different from those in Network 2 (N2), and thus where one, or more protocol discontinuity will occur in an interworking path created to span both N1 and N2. This discontinuity may occur within a single given layer, some set of given layers, or within all layers between the respective networks. + +### 5.2 Possible solutions + +Two solutions are possible to achieve end-to-end connectivity. + +One is to effect a semantically equivalent translation between Network 1 (N1) and Network 2 (N2). The semantic equivalence can be achieved by mapping equivalent service characteristics from N1 to N2. The basic concept is shown in Figure 2, below. + +--- + +1 See ITU-T Rec. G.805, for further definitions of trail, etc. In this Recommendation, the use of the term "layer" or "protocol layer" is synonymous with the use of the term "layer network" in ITU-T Rec. G.805. + +![Diagram showing two separate ovals labeled 'Network 1' and 'Network 2' connected by a double-headed arrow. Below the arrow is the text 'Mapping of service characteristics'. The label 'Y.1251_F02' is at the bottom right.](ebff22fb5dd6f50a90e44dca0f82f285_img.jpg) + +Mapping of +service characteristics + +Y.1251\_F02 + +Diagram showing two separate ovals labeled 'Network 1' and 'Network 2' connected by a double-headed arrow. Below the arrow is the text 'Mapping of service characteristics'. The label 'Y.1251\_F02' is at the bottom right. + +**Figure 2/Y.1251 – Interworking by service mapping/translation between N1 and N2** + +This solution is only possible if there is sufficient similarity in service characteristics between N1 and N2. In this solution, there is a distinct discontinuity between the protocol layer(s) of N1 and N2. Thus, there is a protocol discontinuity between the user of network N1 and users of network N2. Some services of N1 may not be available to users of N2 and vice versa, due to lack of exact equivalence between all the services of N1 and all the services of N2. + +This solution is known as **Service Interworking**. + +The other way to achieve end-to-end connectivity is to superimpose one network on top of the other. This can be achieved by encapsulating, via an adaptation function, the relevant protocol(s), one or more, of one network on top of the protocols of the other. This is shown simplistically in Figure 3 for providing the users of N2 with access to N1. In this solution the users of N2 have to deal with the protocol layer(s) of both N2 and N1 (to some or all extent depending on the exact interworking arrangements), when intercommunication between users of N2 and N1 is required. + +![Diagram showing two overlapping ovals. The larger oval on the left is labeled 'Network 1'. The smaller oval on the right is labeled 'Network 2' and overlaps with the right side of 'Network 1'. The label 'Y.1251_F03' is at the bottom right.](367926125450c2bc3f4bdca9d59a62ba_img.jpg) + +Y.1251\_F03 + +Diagram showing two overlapping ovals. The larger oval on the left is labeled 'Network 1'. The smaller oval on the right is labeled 'Network 2' and overlaps with the right side of 'Network 1'. The label 'Y.1251\_F03' is at the bottom right. + +**Figure 3/Y.1251 – Interworking by superimposition (Encapsulation)** + +This second method encapsulates the protocol(s) of N1 within the uppermost protocol of N2. Users of N2, wishing to communicate with users of N1 must use the new stack comprising the N2 stack plus the additional elements of the N1 stack used for the interworking. Theoretically, this new stack may be regarded as a new logical network N3, since users of N2 still communicate amongst themselves using the original N2 stack. + +This solution is known as **Network Interworking**. It may also sometimes be called interworking by encapsulation. + +In this case there is no protocol discontinuity between users of N1 and users of N2 at the superimposed interworking layer(s). + +Equally possible, but not shown in the figure, protocols of N2 could be superimposed over N1. + +The functions for interworking between N1 and N2, for either **service interworking** or **network interworking**, are provided by an interworking function (IWF) considered to notionally exist between the N1 and N2, as shown in Figure 4. The exact physical location of the interworking unit (IWU) containing the IWF is an implementation issue, but could be contained within N1, N2, or as an independent unit. + +![Figure 4/Y.1251 – Interworking function. This diagram illustrates the interworking function between two networks, Network 1 and Network 2. Network 1 contains Protocol stack 1, which is divided into three horizontal layers: Management plane, Control plane, and User plane. Network 2 contains Protocol stack 2, also divided into Management plane, Control plane, and User plane. Between the two networks is an Interworking Function (IWF). Double-headed arrows indicate bidirectional communication between the Management planes, Control planes, and User planes of the two stacks, as well as between each stack and the IWF. The label 'Y.1251_F04' is located in the bottom right corner.](a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg) + +Figure 4/Y.1251 – Interworking function. This diagram illustrates the interworking function between two networks, Network 1 and Network 2. Network 1 contains Protocol stack 1, which is divided into three horizontal layers: Management plane, Control plane, and User plane. Network 2 contains Protocol stack 2, also divided into Management plane, Control plane, and User plane. Between the two networks is an Interworking Function (IWF). Double-headed arrows indicate bidirectional communication between the Management planes, Control planes, and User planes of the two stacks, as well as between each stack and the IWF. The label 'Y.1251\_F04' is located in the bottom right corner. + +**Figure 4/Y.1251 – Interworking function** + +## 6 Protocol adjacency relationships + +The two methods of interworking described in clause 5 result in the need to position protocols in two different ways. The service interworking method results in the establishment of a horizontal positioning relationship between the protocols of N1 and N2. The network interworking method results in a vertical positioning relationship between the protocols of N1 and N2. + +These basic positioning relationships are shown in Figure 5. + +Two basic principles are involved, namely a vertical layering principle and a horizontal peering principle. Note, these principles are identical to those described in ITU-T Rec. Y.1001, see [3]. + +![Figure 5/Y.1251 – Protocol adjacency relationships. This diagram shows the relationships between three protocols: Protocol A, Protocol B, and Protocol X. Protocol A and Protocol B are enclosed in a dashed box, indicating a layering relationship where Protocol A is encapsulated within Protocol B. A thick double-headed vertical arrow between them is labeled 'Layering relationship'. Protocol A and Protocol X are shown outside this box, with a thick double-headed horizontal arrow between them labeled 'Peering relationship'. Arrows labeled 'Service mapping & adaptation' point from Protocol A to Protocol B and from Protocol X to Protocol A. An arrow labeled 'Service mapping & protocol translation' points from Protocol X to Protocol A. The label 'Y.1251_F05' is in the bottom right corner.](053f1077d592e6622cd21dc4bb4cb366_img.jpg) + +Figure 5/Y.1251 – Protocol adjacency relationships. This diagram shows the relationships between three protocols: Protocol A, Protocol B, and Protocol X. Protocol A and Protocol B are enclosed in a dashed box, indicating a layering relationship where Protocol A is encapsulated within Protocol B. A thick double-headed vertical arrow between them is labeled 'Layering relationship'. Protocol A and Protocol X are shown outside this box, with a thick double-headed horizontal arrow between them labeled 'Peering relationship'. Arrows labeled 'Service mapping & adaptation' point from Protocol A to Protocol B and from Protocol X to Protocol A. An arrow labeled 'Service mapping & protocol translation' points from Protocol X to Protocol A. The label 'Y.1251\_F05' is in the bottom right corner. + +**Figure 5/Y.1251 – Protocol adjacency relationships** + +### 6.1 Layering principle + +In this case, there is a vertical relationship between Protocol A and Protocol B. This is a layering relationship. + +Protocol A is encapsulated within Protocol B, and uses the layer service offered by Protocol B. In general, no fixed relationship between the actual protocols playing in the role of Protocol A or Protocol B can be assumed. In general, protocols can be combined in arbitrary ways. For, example, + +Frame Relay can be operated over IP, or IP may be operated over Frame Relay according to the circumstances pertaining. + +As far as the adaptation is concerned, an adaptation protocol may or may not involve additional protocol control information (PCI) of a shim layer format, depending on the type of mapping required. In some cases, the adaptation may simply be a question of a mapping procedure with no additional PCI being required. In other cases, additional PCI may be required to effect the encapsulation process. + +### 6.2 Peering principle + +In this case, an end-to-end service is being provided by performing a translation and conversion function between Protocol A and Protocol X, via some form of IWF interposed between Protocol A and Protocol X. The IWF terminates each protocol (Protocol A and Protocol X) and performs a mapping between the services offered by Protocol A and Protocol X. + +## 7 Generic interworking model + +The cases described above apply in general to a variety of complex protocol arrangements. Generally, all these cases can be specified in terms of horizontal and/or vertical relationships between adjacent protocols. In this regard, for modelling purposes, it is only necessary to consider two adjacent horizontal protocols and two vertical protocols as shown in Figure 6. All cases, can be fully described by such a model either by degeneration for the case of single layer, or recursive application of the model to the other adjacencies that would exist in a multi-layer situation. This principle applies to the user, control and management planes. + +![Figure 6/Y.1251 – Generic interworking model diagram](5e92d9e8e9ce204e405bff2367f88176_img.jpg) + +The diagram illustrates the Generic interworking model. It consists of four rectangular boxes arranged in a 2x2 grid. The top-left box is labeled 'Protocol A', the top-right box is labeled 'Protocol X', the bottom-left box is labeled 'Protocol B', and the bottom-right box is labeled 'Protocol Y'. Between the top row and bottom row, there are two vertical double-headed arrows. The left arrow is labeled 'A/B Adaptation functions' and the right arrow is labeled 'X/Y Adaptation functions'. Between the left column and right column, there are two horizontal double-headed arrows, both labeled 'Translation functions'. The diagram shows the relationships between protocols in both horizontal and vertical dimensions. + +Y.1251\_F06 + +Figure 6/Y.1251 – Generic interworking model diagram + +**Figure 6/Y.1251 – Generic interworking model** + +Every interworking arrangement can now be described by comparing the horizontal protocol adjacencies, A-X and B-Y, and vertical adjacencies A-B and X-Y. The model can be re-applied to all pairwise adjacencies, to analyze the entire relationship and possible solutions for between any two disparate protocol stacks belonging to different networks. + +For example, if protocol A is not equal to protocol X, but sufficient semantic equivalence exists, protocol A could be translated to X by a semantic functional mapping elements of the interworking functions contained in an interworking unit. This case also embraces the concept service interworking case, where end-to-end semantics across the IWF are preserved by service mapping. + +Alternatively, if this is not possible or desirable, then a common protocol, say protocol A, must be used on both sides (i.e., protocol X becomes the same as protocol A) and is encapsulated within protocol Y by some interworking adaptation function. This is the case of superimposing N1 over N2, interworking by encapsulation. An adaptation protocol may or may not involve additional protocol control information (PCI) of a shim layer format, depending on the type of mapping required. This embraces the concept of network interworking. + +It should be noted that in this Recommendation the use of the term peer-to-peer will not be associated with any given protocol, for the following reasons: + +- a) All protocols that generate formats (i.e., specific and explicit syntax) are peer-to-peer, in that there is always source for generating the protocol format and sink for receiving the protocol in a given stratum of operation (in the same layer or sub-layer). This fact says nothing about the specific role of any specific protocol itself, i.e., what it is being used for, or anything about its type. +- b) Some interworking adaptation protocols do not generate any format (syntax) as such. This is true of many interworking protocols which provide mapping functions from one layer to a lower layer. These are still be peer-to-peer, i.e., implicitly operating between corresponding remote peer entities. For example, Fragmentation and Reassembly procedures fall into this category, in that they have defined procedures but generate no format for transmission and/or reception. +- c) It is not possible to label a protocol as being of a particular absolute kind. Any given protocol can play many different roles in different contexts. There are numerous examples, where protocols may play different roles in different contexts. + +## **8 Application of the model to service interworking and network interworking** + +The following two clauses show application of the generic model to the Service Interworking and Network Interworking cases. + +### **8.1 Service interworking** + +Figure 7 shows an example of service interworking by service mapping. In this example, there is a protocol discontinuity at the interworking layer, since protocol A and protocol X are not identical. Mapping and translation functions are used to convert the services provided by protocol A into formats and services provided by protocol X. + +![Diagram illustrating the application of a model to service interworking between four protocols: Protocol A, Protocol X, Protocol B, and Protocol Y.](af7916c89a458fdab6c3f443217388ae_img.jpg) + +The diagram illustrates the application of a model to service interworking between four protocols: Protocol A, Protocol X, Protocol B, and Protocol Y. The protocols are arranged in a 2x2 grid. Protocol A is at the top-left, Protocol X at the top-right, Protocol B at the bottom-left, and Protocol Y at the bottom-right. The connections between the protocols are as follows: + +- Protocol A and Protocol X:** Connected by a horizontal double-headed arrow labeled "Interworking translation functions". Below this arrow, the text "A not equal X" is present. +- Protocol A and Protocol B:** Connected by a vertical double-headed arrow labeled "A/B Adaptation functions". +- Protocol X and Protocol Y:** Connected by a vertical double-headed arrow labeled "X/Y Adaptation functions". +- Protocol B and Protocol Y:** Connected by a horizontal double-headed arrow labeled "Interworking translation functions". Above this arrow, the text "B equal Y, or B not equal Y" is present. + +The diagram is labeled "Y.1251\_F07" in the bottom right corner. + +Diagram illustrating the application of a model to service interworking between four protocols: Protocol A, Protocol X, Protocol B, and Protocol Y. + +**Figure 7/Y.1251 – Application of model to service interworking** + +### 8.2 Network interworking + +Figure 8 shows the case where the protocol of N1 is superimposed over the protocol of N2 to effect interworking. In this case, protocol A is transferred across the IWF to become protocol X. Thus it is, in fact, protocol A, which now has to be encapsulated over protocol Y, via some suitable adaptation function and may be an additional adaptation shim layer protocol. In this case, there are protocol discontinuities at layers B and Y, but no protocol discontinuity at the upper layer since protocol X is identical to protocol A, i.e., there is a single common protocol across N1 and N2 (for interworking purposes). + +![Figure 8/Y.1251: Application of model to Network Interworking. This diagram illustrates a network interworking model. At the top, 'Protocol A' and 'Protocol X' are connected by a bidirectional arrow, with a box labeled 'A equal X' between them. Below this, 'Protocol B' and 'Protocol Y' are connected by a bidirectional arrow, with a box labeled 'B not equal Y' between them. In the center, 'Interworking translation functions' are shown. On the left, 'A/B Adaptation functions' connect 'Protocol A' and 'Protocol B'. On the right, 'X/Y Adaptation functions' connect 'Protocol X' and 'Protocol Y'. The diagram is labeled 'Y.1251_F08' at the bottom right.](4801720824e4b5e2361a5564f91cfb70_img.jpg) + +Figure 8/Y.1251: Application of model to Network Interworking. This diagram illustrates a network interworking model. At the top, 'Protocol A' and 'Protocol X' are connected by a bidirectional arrow, with a box labeled 'A equal X' between them. Below this, 'Protocol B' and 'Protocol Y' are connected by a bidirectional arrow, with a box labeled 'B not equal Y' between them. In the center, 'Interworking translation functions' are shown. On the left, 'A/B Adaptation functions' connect 'Protocol A' and 'Protocol B'. On the right, 'X/Y Adaptation functions' connect 'Protocol X' and 'Protocol Y'. The diagram is labeled 'Y.1251\_F08' at the bottom right. + +**Figure 8/Y.1251 –Application of model to Network Interworking** + +A common usage/application of this method involves three physically separate networks, where two similar networks N1 and N3 are interconnected via a third dissimilar network N2, as shown in Figure 9. + +![Figure 9/Y.1251: Example of Network Interworking. This diagram shows three networks: N1, N2, and N3. N1 and N3 are connected to N2 via two 'IWU' (Interworking Units). N1 contains 'Protocol A' and 'Protocol B'. N2 contains 'Protocol X (X := A)' and 'Protocol Y'. N3 contains 'Protocol A' and 'Protocol B'. Bidirectional arrows connect 'Protocol A' in N1 to 'Protocol X' in N2, and 'Protocol A' in N3 to 'Protocol X' in N2. Bidirectional arrows connect 'Protocol B' in N1 to 'Protocol Y' in N2, and 'Protocol B' in N3 to 'Protocol Y' in N2. The diagram is labeled 'Y.1251_F09' at the bottom right.](a33da0f14e456f92539ce3e9b7d81f9a_img.jpg) + +Figure 9/Y.1251: Example of Network Interworking. This diagram shows three networks: N1, N2, and N3. N1 and N3 are connected to N2 via two 'IWU' (Interworking Units). N1 contains 'Protocol A' and 'Protocol B'. N2 contains 'Protocol X (X := A)' and 'Protocol Y'. N3 contains 'Protocol A' and 'Protocol B'. Bidirectional arrows connect 'Protocol A' in N1 to 'Protocol X' in N2, and 'Protocol A' in N3 to 'Protocol X' in N2. Bidirectional arrows connect 'Protocol B' in N1 to 'Protocol Y' in N2, and 'Protocol B' in N3 to 'Protocol Y' in N2. The diagram is labeled 'Y.1251\_F09' at the bottom right. + +**Figure 9/Y.1251 – Example of Network Interworking** + +In such a case we have application of two IWUs. Both the IWFs apply adaptation functions, i.e., encapsulation and decapsulation at the border between N1 and N2 and at the border between N2 and N3 for the bidirectional carriage of the common N1/N3 protocol over N2. In this case, the protocol of N1/N3 is carried transparently over N2. When only two dissimilar networks are involved one of the end systems could be regarded as constituting a third network handling the common protocol. + +## 9 Related principles + +In general, it can be stated that whenever any protocol stack difference exists between two networks, interworking is required to interconnect the two networks. This general principle is independent of the method used to achieve such interworking, i.e., irrespective of whether the service interworking method of 8.1 or the network interworking of 8.2 is used to effect such interworking. + +Any protocol discontinuity between N1 and N2, at any layer of their respective stacks, constitutes interworking. For example, if N1 were IP over a Local Area Network and N2 was IP over Frame Relay, interworking is taking place between the Local area Network and the Frame Relay network because of the layer 2 discontinuity, even though there is no discontinuity at layer 3 (the IP layer). Adaptation functions are required for IP over the LAN layer 2 protocol and for IP over the Frame Relay protocol. + +If layer N is the uppermost layer from the interworking standpoint, there must be at least one layer protocol discontinuity between the protocol stacks of networks N1 and N2 for their interconnection to be considered as an interworking case. This discontinuity may occur at layer N itself, or at any other layer N-j (for j less than N; j greater equal 1), or at several layers simultaneously including or excluding the layer N itself. It should also be noted that the number of layer protocols in each stack may be different. + +In general, mappings between features may span several layers. It cannot be assumed that mappings performed purely at a peer level are sufficient, or that each peer layer is independent of the underlying layer(s). For example, a particular feature at layer N in N1 may be required to be mapped to non-peer layer in N2. These considerations may apply particularly to QoS related features and/or aspects. + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|--------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series B | Means of expression: definitions, symbols, classification | +| Series C | General telecommunication statistics | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | TMN and network maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks and open system communications | +| Series Y | Global information infrastructure and Internet protocol aspects | +| Series Z | Languages and general software aspects for telecommunication systems | + +![Barcode graphic with the number * 2 2 8 0 6 * printed below it.](97fe9069356cc2a84e8e70673e405958_img.jpg) + +A standard 1D barcode is located in the bottom right corner of the page. Below the vertical bars of the barcode, the alphanumeric string '\* 2 2 8 0 6 \*' is printed. + +Barcode graphic with the number \* 2 2 8 0 6 \* printed below it. \ No newline at end of file diff --git a/marked/Y/T-REC-Y.1271-201407-I_PDF-E/14a22f23ced8ba1d63ece69861dbaacc_img.jpg b/marked/Y/T-REC-Y.1271-201407-I_PDF-E/14a22f23ced8ba1d63ece69861dbaacc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..072f073b6d42cbfa77c827c76c611f286177034a --- /dev/null +++ b/marked/Y/T-REC-Y.1271-201407-I_PDF-E/14a22f23ced8ba1d63ece69861dbaacc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:ee72ddf991b7b1d543b2694b1687804845ecb97da77cc35e98e4c7dbf5ac163d +size 4142 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/05eb72d372e4bf78e3d6a64949d77bcc_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/05eb72d372e4bf78e3d6a64949d77bcc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..b44492d09a5c81655fa9004f342b89f8c5333647 --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/05eb72d372e4bf78e3d6a64949d77bcc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:fa3dfabca5b4dd6bd10a74623dd3d67d3182601d2b9b682172f577f37aa12064 +size 24921 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/0c08e48c08f96934cd6bc6911f3069dc_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/0c08e48c08f96934cd6bc6911f3069dc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..b902e1b8cd74b897136e2c4156e2696c7e522b3c --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/0c08e48c08f96934cd6bc6911f3069dc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:a2054e780100b97fc36a019f3126940520b71426f44819ee1471c6fa5fd6fd89 +size 33817 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/1893e9dc091ea311057341f98b65310b_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/1893e9dc091ea311057341f98b65310b_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..7237417d651604a656b2f51e344883814daf8e5b --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/1893e9dc091ea311057341f98b65310b_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:06da909971e854324b1d3267a86baf7c3e43bc70b2bf65142fd8bab16962dae8 +size 102523 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/1acc7c1338d89d86a162eb4ebedae856_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/1acc7c1338d89d86a162eb4ebedae856_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..811f313b87204303a613b3c430ee10fc63c6c040 --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/1acc7c1338d89d86a162eb4ebedae856_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:9185e3ee4aa3b9abf86dd6608ad73a6bef0ba720581f439e90c1c6c14ae6d67f +size 37036 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/1d3994bfe548ae7545d57df703e32a02_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/1d3994bfe548ae7545d57df703e32a02_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..4a4e4e05fa6edfc4c8192084802555bbc656ff8b --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/1d3994bfe548ae7545d57df703e32a02_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:8cff8bee7add92231910ffb7bbdfe45fdad6a996398ef6388571fe16f46750ab +size 78978 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/21327313f7b18a481da0c87a6472a80d_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/21327313f7b18a481da0c87a6472a80d_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..337c0541d54a424cda363abf9960e1937baf5fc8 --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/21327313f7b18a481da0c87a6472a80d_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:d3d339fc0b56a014426f803f3b671a8ce9076e72b0b913a2ad8aeb342e867105 +size 73653 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/237b76118be454462fc9b4e96adaa6c7_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/237b76118be454462fc9b4e96adaa6c7_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..67ebde31d4b449773cbd46d5862cb98c184ad9e0 --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/237b76118be454462fc9b4e96adaa6c7_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:ca15d390f75cfb3838299949bd647efa46357a12d24aa2a357b22b69313e8873 +size 102898 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/2cf3896394a2342a2b46c504ab9a8830_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/2cf3896394a2342a2b46c504ab9a8830_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..e6401d26aa0f0905e096526ea7ffa9cd67fdfb58 --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/2cf3896394a2342a2b46c504ab9a8830_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:23ab43858e3026cc2cf7c27b800a531f30234174d372a963bbd9999af449416b +size 53249 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/318886a86a1dcc59e1fc83db6f157c60_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/318886a86a1dcc59e1fc83db6f157c60_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..ce95e80a5281c0888358b94b65d37040a3d0bea5 --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/318886a86a1dcc59e1fc83db6f157c60_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:02db9cd6f0172d030dd15abc91af429e9ef2be576b0f0b11ceef63ab1477a5e8 +size 34337 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/3337af75dfee8af7687b4f49914d6c93_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/3337af75dfee8af7687b4f49914d6c93_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..cd19fb85974ff359359ada7c99fc984da538d012 --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/3337af75dfee8af7687b4f49914d6c93_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:7fe22c9b005508bec2f7c757309fa3ac84f2529e43f0b5f01e0e82dae2f14374 +size 36937 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/366a77fdefb0097b3289b4a011911390_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/366a77fdefb0097b3289b4a011911390_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..9e6b5bae0deef4921c1a53390d77a871e81a96b4 --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/366a77fdefb0097b3289b4a011911390_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:ec491bd9a3af71756ab63aeddc62df701644913744bc9d6534f37ec332de672a +size 80480 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/474a819357587e34949a3e110ff19b30_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/474a819357587e34949a3e110ff19b30_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..81eaec057e46605437e30bac67ff0ff247b9193c --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/474a819357587e34949a3e110ff19b30_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:14dc42ffa82461de4bc434965c4e2d48578a97f49edc88010f96aa579b373e86 +size 78487 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/47a7beddcb8a1b7abdca746967e32bb4_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/47a7beddcb8a1b7abdca746967e32bb4_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..550d19d085591ede59579a76bda4a46424f8f446 --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/47a7beddcb8a1b7abdca746967e32bb4_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:e9c1e95026534bbbfecbb3aeb911248b9f0aa075b17943aea73e9dd89fc7760b +size 38405 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/5414f65867392f05ba0063b208eeb5e1_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/5414f65867392f05ba0063b208eeb5e1_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..e683141d984e8f9c44049fbb477f5fe4345d87a7 --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/5414f65867392f05ba0063b208eeb5e1_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:d7f6f9b3c476fd7ad57ab1c0fbb460ed0b971c8e358115f0785eb92184e28833 +size 53025 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/5445597cceefaca1ac89e710fe339325_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/5445597cceefaca1ac89e710fe339325_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..95f10c6e8d32ecd5427cfd8c4e170e3d1332a4de --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/5445597cceefaca1ac89e710fe339325_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:54bc5d2a48772975c10cb9bd8ba55a4c3acfe22dac73f6be9cbd856c7e02195f +size 37174 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/58f4167687de8d7339594e5f6fbe0bc6_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/58f4167687de8d7339594e5f6fbe0bc6_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..eb7d25ceb67dca72a8c11de01bf6a644d0615112 --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/58f4167687de8d7339594e5f6fbe0bc6_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:b02cfd5bf648a03b0b45e9aa83fa2f242c9951fa6eda720d2de67efa326360c6 +size 100992 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/6470d350326789d5306eabcb76533951_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/6470d350326789d5306eabcb76533951_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..7ef09e07a0df0cf7df2c1c25f268444e501ffe10 --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/6470d350326789d5306eabcb76533951_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:4fd7ee45ba096ab67b7aa55b4b9bc578776bcbb4b5f0772bc7b1c031a4e3407f +size 27939 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/67114ecf6da13c97a89aeff0d86885d5_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/67114ecf6da13c97a89aeff0d86885d5_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..c2a171f776cc3e90bc7b5501d222c00e56a63332 --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/67114ecf6da13c97a89aeff0d86885d5_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:000fb19ab4536edd98f55a7f37a35b20639eafb427db726d907884deaa539847 +size 48183 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/812e188283162af0b54fb3e30ffee51b_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/812e188283162af0b54fb3e30ffee51b_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..07ab69c09db70de87ed03cb0acfacb1338f4fa41 --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/812e188283162af0b54fb3e30ffee51b_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:1cd8f3dee9985d5cf9b672454e57f28fa45e9c8d9a8f3dbbda7cac8396c4c0ac +size 89067 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/8c348bf9c2c81b018017ae1d19506a9a_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/8c348bf9c2c81b018017ae1d19506a9a_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..f530adacab65478c58bb21c70650e7c7217feb0c --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/8c348bf9c2c81b018017ae1d19506a9a_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:8b1fd2c4c0e6516f4526b9cc28182e9f2938dc37de35851fb96b9d41486fc6e3 +size 38521 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/8fa679f79a1bb1f527cba9f29e784e89_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/8fa679f79a1bb1f527cba9f29e784e89_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..e709943b10488f870ecba17b9ff16e7015537e1c --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/8fa679f79a1bb1f527cba9f29e784e89_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:c3d18e4c1f5807ce968ef908d8cdf5a0d9fa9977634c8c85711e9839808d26f7 +size 36729 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/9b1ec0090070bdf52ea28763b8d52477_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/9b1ec0090070bdf52ea28763b8d52477_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..c2c6fd8ad9d50434e3b14818cae9cafb375c9329 --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/9b1ec0090070bdf52ea28763b8d52477_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:bb6a96ec84341eaa394057757f9202b3c5ce141134f0869bf9a149600fa4d387 +size 100126 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/9e8ebf03cae78f4f81b697548c2d7250_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/9e8ebf03cae78f4f81b697548c2d7250_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..1861be1fe7ec50b239fb2c84ea165ea70e8dbeef --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/9e8ebf03cae78f4f81b697548c2d7250_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:92b1d8c013a553c5c48aa4df29f85cc65994849890ee0ca73faee5ef4d16951d +size 37111 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/a149b400127a3e3e50b3c98d27c5935c_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/a149b400127a3e3e50b3c98d27c5935c_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..d40e055e0d9e62866e378dc25dd1d92e27e4e075 --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/a149b400127a3e3e50b3c98d27c5935c_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:c8cfb237637cb4fc081a1dcb3d36549a39705f67a9dd262d8310c171d0460057 +size 99500 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/a3dc41dc3df86ea68d266af2bf95cf5b_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/a3dc41dc3df86ea68d266af2bf95cf5b_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..36cf51f8ba07e44aa7a4b009f3ba08eb2b570b1c --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/a3dc41dc3df86ea68d266af2bf95cf5b_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:11780faeee75ba39ab4ed9de67a9e67abec0d9ba3068ebec661dea70c16e29d3 +size 4338 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/b6ad8b32179842fca5ad086cf22b03eb_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/b6ad8b32179842fca5ad086cf22b03eb_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..fe905a4323d32a0e9fcf20b84410b7d650cd8d48 --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/b6ad8b32179842fca5ad086cf22b03eb_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:e8f3be93b1bb6e5a72f259a9bd26d2187d00ab7320ead114e7071d35c47e29fd +size 95655 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/b904ac2472cab80892d1e783e6230d6e_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/b904ac2472cab80892d1e783e6230d6e_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..afb9dfac273ac1115cf417b33d40c971f963c56f --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/b904ac2472cab80892d1e783e6230d6e_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:94f3137a7d3135538b0e8886d67dcbcaa1a42f7f1299540a4a3d396a0b443949 +size 28214 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/cbab05075b3d7dc0d27c4cbb0c914a94_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/cbab05075b3d7dc0d27c4cbb0c914a94_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..c56f251bb50c6ca159df3a99e6e6d2ad4d3cd254 --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/cbab05075b3d7dc0d27c4cbb0c914a94_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:4b4df21346a0f73e4d1a07a7c9aa820258eae4d4b7e78a28f66965d2e0397de0 +size 87469 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/cc98b584f9b31fe69948e3fa65a3ba69_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/cc98b584f9b31fe69948e3fa65a3ba69_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..d616d80d9e564674601a6e408e7dd97579a2a41a --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/cc98b584f9b31fe69948e3fa65a3ba69_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:f337c9309477cdf2d8ca0c251f9db25c2184dde063dacb3bab5295b1493c1efb +size 132451 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/d53cd0fd1cf896a9353fd63de1505ba2_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/d53cd0fd1cf896a9353fd63de1505ba2_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..9ed4bc9cb063f734a22d456d4647f8b6eeb62106 --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/d53cd0fd1cf896a9353fd63de1505ba2_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:9fd12dbd53812e3df0bffec151d70a562ad27b48db0fe2e1b15584f161c1b50b +size 81812 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/d734a6ea1b381280f043fcf70391b6db_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/d734a6ea1b381280f043fcf70391b6db_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..28a651bc3464a93ab904ef4748b7790d0cec7ecf --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/d734a6ea1b381280f043fcf70391b6db_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:13d442eba0220fac43e2475c1f2aedda91491dcef9cf1a26253a55ab46f1f982 +size 84007 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/d9843ac5dfc4bbe9e4d21b8898723b5e_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/d9843ac5dfc4bbe9e4d21b8898723b5e_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..c6132aeee7449743ea003eb2bfc3ccb94f78c620 --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/d9843ac5dfc4bbe9e4d21b8898723b5e_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:ab1d92eff2b4f596f1bf80f9d940e28a8ebfc65d8368e1f7d192d7685d2752b8 +size 47512 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/dfe556fea00682b09a59427aaf72051c_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/dfe556fea00682b09a59427aaf72051c_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..a94696fbf51a10e306d61976d5e93691d1534b26 --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/dfe556fea00682b09a59427aaf72051c_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:29eb1de2e4e7854220e6f5b6e62f574210a331d2bab8e3b3d0b5d44123fa7d99 +size 47805 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/eb5677b570ab2a3e9d8f5d35ca5b8a4d_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/eb5677b570ab2a3e9d8f5d35ca5b8a4d_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..ff24c99731663e2d5141c3d916c0a7fc563319c3 --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/eb5677b570ab2a3e9d8f5d35ca5b8a4d_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:519a14a2efa5615796ecf6cf0bf3c4ebdabd052d76452ddf8fde5ac30448ca7c +size 124715 diff --git a/marked/Y/T-REC-Y.1314-200510-I_PDF-E/f5deee2f3301ee351c4008283ffafbb3_img.jpg b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/f5deee2f3301ee351c4008283ffafbb3_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..72325cf486db2949f34ed30e0c69e47a9d3105f5 --- /dev/null +++ b/marked/Y/T-REC-Y.1314-200510-I_PDF-E/f5deee2f3301ee351c4008283ffafbb3_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:34f8cb89739e04d2d1265dfc1297e8096fae6e4576b677af98c5127d215460bb +size 108946 diff --git a/marked/Y/T-REC-Y.1315-200609-I_PDF-E/raw.md b/marked/Y/T-REC-Y.1315-200609-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..c7f391d8c433a165a6e2684fbc5c32e1c712e8ca --- /dev/null +++ b/marked/Y/T-REC-Y.1315-200609-I_PDF-E/raw.md @@ -0,0 +1,743 @@ + + +I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +# Y.1315 + +(09/2006) + +SERIES Y: GLOBAL INFORMATION +INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS +AND NEXT-GENERATION NETWORKS + +Internet protocol aspects – Transport + +# --- **QoS support for VPN services – Framework and characteristics** + +ITU-T Recommendation Y.1315 + +## ITU-T Y-SERIES RECOMMENDATIONS GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT- GENERATION NETWORKS + +## GLOBAL INFORMATION INFRASTRUCTURE + +| | | +|-------------------------------------------|-------------| +| General | Y.100–Y.199 | +| Services, applications and middleware | Y.200–Y.299 | +| Network aspects | Y.300–Y.399 | +| Interfaces and protocols | Y.400–Y.499 | +| Numbering, addressing and naming | Y.500–Y.599 | +| Operation, administration and maintenance | Y.600–Y.699 | +| Security | Y.700–Y.799 | +| Performances | Y.800–Y.899 | + +## INTERNET PROTOCOL ASPECTS + +| | | +|--------------------------------------------------------------------|---------------| +| General | Y.1000–Y.1099 | +| Services and applications | Y.1100–Y.1199 | +| Architecture, access, network capabilities and resource management | Y.1200–Y.1299 | + +### **Transport** **Y.1300–Y.1399** + +| | | +|--------------------------------------------|---------------| +| Interworking | Y.1400–Y.1499 | +| Quality of service and network performance | Y.1500–Y.1599 | +| Signalling | Y.1600–Y.1699 | +| Operation, administration and maintenance | Y.1700–Y.1799 | +| Charging | Y.1800–Y.1899 | + +## NEXT GENERATION NETWORKS + +| | | +|-------------------------------------------------------------------|---------------| +| Frameworks and functional architecture models | Y.2000–Y.2099 | +| Quality of Service and performance | Y.2100–Y.2199 | +| Service aspects: Service capabilities and service architecture | Y.2200–Y.2249 | +| Service aspects: Interoperability of services and networks in NGN | Y.2250–Y.2299 | +| Numbering, naming and addressing | Y.2300–Y.2399 | +| Network management | Y.2400–Y.2499 | +| Network control architectures and protocols | Y.2500–Y.2599 | +| Security | Y.2700–Y.2799 | +| Generalized mobility | Y.2800–Y.2899 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# **ITU-T Recommendation Y.1315** + +# **QoS support for VPN services – Framework and characteristics** + +## **Summary** + +ITU-T Recommendation Y.1315 describes the characteristics and applicability of various QoS (quality of service) service scenarios in the VPN (virtual private network) environment. The QoS service scenarios cover various QoS models in single or multiple service provider configurations. The QoS models described in this Recommendation encompass the pipe model, the hose model, and a combination and/or concatenation of both. + +###### **Source** + +ITU-T Recommendation Y.1315 was approved on 13 September 2006 by ITU-T Study Group 13 (2005-2008) under the ITU-T Recommendation A.8 procedure. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g. interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2007 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## CONTENTS + +| | | Page | +|----|--------------------------------------------------------------------------------------------------|-------------| +| 1 | Scope ..... | 1 | +| 2 | References..... | 1 | +| 3 | Definitions ..... | 1 | +| 4 | Abbreviations and acronyms ..... | 2 | +| 5 | QoS definitions ..... | 2 | +| | 5.1 Packet-network-related QoS parameters ..... | 3 | +| | 5.2 Basic QoS mechanisms ..... | 4 | +| 6 | Network input and service specification..... | 4 | +| | 6.1 Input traffic characteristics ..... | 4 | +| | 6.2 Service specification..... | 5 | +| 7 | QoS architectural components..... | 6 | +| | 7.1 Data plane architectural components..... | 6 | +| | 7.2 Control plane architectural components..... | 7 | +| | 7.3 Management plane architectural components ..... | 8 | +| | 7.4 Enhancements for Y.1291 ..... | 8 | +| 8 | VPN service based on the pipe model ..... | 8 | +| | 8.1 Definition of pipe model ..... | 8 | +| | 8.2 Customer edge characteristics ..... | 9 | +| | 8.3 Provider equipment characteristics..... | 9 | +| | 8.4 Applicability, complexity, and scalability..... | 10 | +| | 8.5 Constructing the VPN based on the pipe model..... | 11 | +| 9 | VPN service based on the hose model..... | 11 | +| | 9.1 Definition of hose model ..... | 11 | +| | 9.2 Customer edge characteristics ..... | 12 | +| | 9.3 Provider equipment characteristics..... | 12 | +| | 9.4 Applicability, complexity, and scalability..... | 13 | +| 10 | VPN service based on both pipe and hose model..... | 14 | +| 11 | Multiple service provider scenario ..... | 14 | +| | Appendix I – Pipe model-based implementation example of VPN with specific QoS requirements ..... | 16 | +| | I.1 Service requirements ..... | 16 | +| | I.2 Unified QoS-VPN architecture..... | 16 | +| | I.3 Considerations ..... | 17 | +| | Appendix II – Service curve ..... | 19 | +| | Bibliography..... | 20 | + +# **Introduction** + +There are several QoS models available for VPN services. In this Recommendation, the pipe model and the hose model are studied. The objectives of such studies are to provide precise definitions for these QoS models, to construct the VPN using the toolset provided in [ITU-T Y.1291], and to outline applicability of these QoS models in the VPN environment. + +The architectural components needed to build these QoS models are defined in [ITU-T Y.1291] while the mechanisms to coordinate the resources to ensure QoS between sites are defined in the related IETF and ITU-T documents. + +In order to provide VPN services with QoS, the first step is to define the QoS in parametric terms. This is construed as objectives of the services to be provided. The next step is to use the architecture building blocks provided in [ITU-T Y.1291] to construct the VPN with QoS, and the final step is to evaluate the service performance provided by the network. This Recommendation refers to [ITU-T Y.1291] on the functions and features of the QoS architectural components. + +This Recommendation takes input from the various VPN related ITU-T deliverables, including approved Recommendations (e.g., [ITU-T Y.1311], [ITU-T Y.1311.1], [ITU-T Y.1312], and [ITU-T Y.1314]). + +# ITU-T Recommendation Y.1315 + +## QoS support for VPN services – Framework and characteristics + +# 1 Scope + +The scope of this Recommendation is to provide guidelines on how the QoS architecture tools, mostly provided in [ITU-T Y.1291], can be used to support VPN services with QoS characteristics between the network ingress points to the network egress points. In this Recommendation, different QoS service models, including the pipe model and the hose model, are studied. The characteristics and applicability of VPN services using those QoS models and concatenation of multiple QoS models in a single or multiple provider scenarios are also studied, including some application examples. + +While this Recommendation discusses the QoS issues related to VPN applications, the mechanisms to ensure QoS assurance are out of the scope of this Recommendation. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- [ITU-T E.800] ITU-T Recommendation E.800 (1994), *Terms and definitions related to quality of service and network performance including dependability.* +- [ITU-T G.1000] ITU-T Recommendation G.1000 (2001), *Communications Quality of Service: A framework and definitions.* +- [ITU-T H.360] ITU-T Recommendation H.360 (2004), *An architecture for end-to-end QoS control and signalling.* +- [ITU-T Y.1291] ITU-T Recommendation Y.1291 (2004), *An architectural framework for support of Quality of Service in packet networks.* +- [ITU-T Y.1311] ITU-T Recommendation Y.1311 (2002), *Network-based VPNs – Generic architecture and service requirements.* +- [ITU-T Y.1311.1] ITU-T Recommendation Y.1311.1 (2001), *Network-based IP VPN over MPLS architecture.* +- [ITU-T Y.1312] ITU-T Recommendation Y.1312 (2003), *Layer 1 Virtual Private Network generic requirements and architecture elements.* +- [ITU-T Y.1314] ITU-T Recommendation Y.1314 (2005), *Virtual private network functional decomposition.* + +# 3 Definitions + +This Recommendation defines the following terms: + +**3.1 arrival curve:** A mechanism to serve as a measure of traffic arriving at provider's ingress network interface. + +**3.2 service curve:** A mechanism to serve as a measure of the packet forwarding services provided by the service provider. + +## **4 Abbreviations and acronyms** + +This Recommendation uses the following abbreviations and acronyms. + +| | | +|----------|--------------------------------------------------------| +| BE | Best Effort | +| CE | Customer Edge | +| CoS | Class of Service | +| CR-LDP | Constraint-based Routing – Label Distribution Protocol | +| Diffserv | Differentiated Services | +| DSCP | DiffServ Code Point | +| EF PHB | Expedited Forwarding Per Hop Behaviour | +| FIFO | First In, First Out | +| FILO | First In, Last Out | +| Intserv | Integrated Services | +| LAPS | Link Access Procedure – SDH | +| LIFO | Last In, First Out | +| LILO | Last In, Last Out | +| LSP | Label Switched Path | +| MPLS | Multi-Protocol Label Switching | +| P | Provider (node) | +| PE | Provider Edge | +| QoS | Quality of Service | +| RSVP | Resource reSerVation Protocol | +| SLA | Service Level Agreement | +| TE | Traffic Engineering | +| UNI | User Network Interface | +| VF | Virtual Forwarder | +| VPN | Virtual Private Network | + +# **5 QoS definitions** + +The concept of quality of service is a multi-dimensional measure of user satisfaction of the network. The various definitions of QoS have been discussed in different ITU-T Recommendations (e.g., [ITU-T E.800] and [ITU-T G.1000]). Under those Recommendations, the network performance characteristics, network operability, network support, network serviceability, and network security are all part of the quality of service. + +In this Recommendation, only the parametric aspects of QoS under the VPN environment for packet-based networks are discussed. The following subclauses provide details about the QoS metrics. + +### 5.1 Packet-network-related QoS parameters + +Among various aspects of quality of service definitions, this Recommendation focuses on the performance aspects of the service provider's network in the VPN environment for the packet-based networks. The measure of the QoS for a particular service provider's packet network providing VPN services should encompass the following aspects: + +- **Delay:** There are various means to measure the time delay experienced by the user traffic. It should be noted that those definitions are not equivalent (e.g., consider if the packet is fragmented inside the network or LAPS-based framing). It should be noted that the service providers are free to use any of those definitions but a consistent definition needs to be provided to the clients if multiple service providers are involved. + - [FIFO delay] First-in, first-out: The time difference between the first bit accepted by the network and the first bit delivered to the user across the network. + - [LILO delay] Last-in, last-out: The time difference between the last bit accepted by the network and the last bit delivered to the user across the network. + - [FILO delay] First-in, last-out: The time difference between the first bit accepted by the network and the last bit delivered to the user across the network. It is possible to define the FILO delay but should not be used because it is packet size sensitive. + - [LIFO delay] Last-in, first-out: The time difference between the last bit accepted by the network and the first bit delivered to the user across the network. It is possible to define the LIFO delay but should not be used because it is packet size sensitive. +- **Delay variation (jitter):** Once a specific type of delay is defined by the network, the delay variation may be further divided into the following sub-categories: + - Maximum delay variation: The difference between the maximum delay and minimum delay experienced by the user traffic within a specific time window. + - Mean delay variation: Within a specific time window $[0, T]$ , if each individual packet delay can be denoted as $d(k)$ for the $k$ th packet in the time window, the mean delay variation can then be denoted as $D_{[0, T]} = \sum_{i=0}^N |d(i) - \bar{D}|$ where $N$ denotes that there are $N$ packets arriving in the time interval $[0, T]$ and $\bar{D}$ is the average delay endured by each packet arriving in the time window $[0, T]$ (i.e., $\bar{D} = \sum_{k=0}^N d(k)$ where $N$ is the total number of packets arrived in the time interval $[0, T]$ ). + - Medium delay variations: $(\bar{M})$ : Within a specific time window $[0, T]$ , 50% of the packet have delay more than $\bar{M}$ and 50% packet will have delay less than $\bar{M}$ . +- **Packet loss probability:** The definition of packet loss probability (as opposed to the pure packet loss counts as some service providers are considering) is also subject to the time window constraint. In this Recommendation, the "packet delivery probability" is defined as the total number of packets successfully delivered divided by the total number of the eligible packets received by the network for a given and well-defined time interval. The eligible packets are then subject to the input constraint. Hence the "packet loss probability" is one minus the "packet delivery probability". + +The particular value of delay, delay variation, and packet loss probability are not specified and are also application specific. + +For delay measurement, the FIFO delay may be ensured analytically for arbitrary packets. Even the LILO delay measurement may be useful for applications; such a delay will be packet content sensitive and difficult to be ensured analytically. + +The mean delay variation and medium delay variation depend on the statistics of the packet being forwarded. Given such statistics are unknown, and media characteristic sensitive, those two types of delay variations are not further pursued in this Recommendation. The focus of this Recommendation is on the maximum delay variation, which can serve as guidance for buffer design in media replay type applications. + +### 5.2 Basic QoS mechanisms + +There are essentially two mechanisms to satisfy SLA regarding QoS in the VPN environment, which can be used to construct pipes and hoses. One is based on the IntServ model and the other is based on the Diffserv model. + +The IntServ mechanism, based on [b-RFC 2205] and its subsequent improvements, can be used to perform bandwidth reservation for a single packet flow or multiple packet flows. It uses the *path* message to advertise the reservation requirements and the *resv* message to actually make the reservation. Once the connection admission control allows the flow, the bandwidth will be dedicated to the flow and parametric QoS assurance is possible under the IntServ environment. + +For packet-based networks, the use of Diffserv mechanisms is being deployed. When Diffserv mechanisms are used, the level of QoS a packet should receive from the network is indicated by the use of DSCP. The DSCP is being used to indicate the service class to which each packet belongs and the QoS treatment provided by the Diffserv capable packet network will be as indicated by the DSCP. + +Differentiated service classes encourage the usage of the service class end-to-end, with the end-user application determining the correct service class to be used by specific application traffic flows. + +For example, a traffic flow belonging to the "telephony" service class will be treated with minimum loss, jitter, and delay in the Diffserv EF PHB. + +The usage of Diffserv service classes allows the communication of QoS requirements between the end user application and the packet network with minimum overhead. + +# 6 Network input and service specification + +In order to properly ensure the parametric QoS boundaries (with parameters given in clause 5.1) for the provider's network, the input traffic of the network and services performed by the service providers need to be characterized. Those characterizations are discussed in clauses 6.1 and 6.2. + +### 6.1 Input traffic characteristics + +In order to discuss the QoS in the VPN environment, the fluid model of the network will be used. In this set-up, the user input traffic will be considered as a continuous bit stream which will be received by the network. The cumulative number of bits received at the time instance $t$ will be denoted as $R(t)$ . + +For a wide-sense increasing function $\alpha$ defined for $t \geq 0$ , the function $R(t)$ is said to be constrained by $\alpha$ if and only if: + +$$R(t) - R(s) \leq \alpha(t - s)$$ + +The function $\alpha$ is also said to be the arrival curve of the $R(t)$ or the $R(t)$ is $\alpha$ -smooth. + +The popular token bucket $(p, M, r, b)$ as defined in [b-RFC 2215], is essentially to limit the input function $R(t)$ by the arrival curve $\alpha$ with: + +$$\alpha(t) = \min(M + pt, rt + b)$$ + +This arrival curve can be shown graphically as in Figure 6-1. + +![Figure 6-1: Arrival curve for traffic limited by token bucket. The graph shows two lines on a coordinate system where the vertical axis is labeled alpha (α) and the horizontal axis is labeled Time t. One line, labeled 'Rate r', starts at a positive value on the alpha axis and has a shallow positive slope. The other line, labeled 'Rate p', starts at the origin (0,0) and has a steeper positive slope. The two lines intersect at a point. Below the graph is the label Y.1315(06)_F6-1.](32cbf74724dd69f0603b24cf051810a9_img.jpg) + +Figure 6-1: Arrival curve for traffic limited by token bucket. The graph shows two lines on a coordinate system where the vertical axis is labeled alpha (α) and the horizontal axis is labeled Time t. One line, labeled 'Rate r', starts at a positive value on the alpha axis and has a shallow positive slope. The other line, labeled 'Rate p', starts at the origin (0,0) and has a steeper positive slope. The two lines intersect at a point. Below the graph is the label Y.1315(06)\_F6-1. + +**Figure 6-1 – Arrival curve for traffic limited by token bucket** + +### 6.2 Service specification + +The service provided by the service provider can also be modelled via a "service curve". + +For almost all the nodes, the service curve will be of the "rate-latency" in nature, which can be illustrated in Figure 6-2. + +![Figure 6-2: Rate-latency service curve with service rate r and latency T. The graph shows a red line on a coordinate system where the vertical axis is labeled 'Accumulated bits' and the horizontal axis is labeled 'Time t'. The red line is horizontal at zero for a duration labeled 'Latency T' on the time axis. After this latency, the line rises with a positive slope labeled 'Rate r'. Below the graph is the label Y.1315(06)_F6-2.](b712e7522f1bb7135730c7d1abb46d43_img.jpg) + +Figure 6-2: Rate-latency service curve with service rate r and latency T. The graph shows a red line on a coordinate system where the vertical axis is labeled 'Accumulated bits' and the horizontal axis is labeled 'Time t'. The red line is horizontal at zero for a duration labeled 'Latency T' on the time axis. After this latency, the line rises with a positive slope labeled 'Rate r'. Below the graph is the label Y.1315(06)\_F6-2. + +**Figure 6-2 – Rate-latency service curve with service rate $r$ and latency $T$** + +For $N$ nodes with service rate $r_i$ and latency with $T_i$ , the resulting service curve will also be of the rate-latency type with rate $r = \min(r_1, \dots, r_N)$ and delay $T = T_1 + \dots + T_N$ . + +In other words, as far as the service rate of the network is concerned, the service rate will be the minimum rate among all the nodes along the path while the delays are additive. It should be noted that the delay bounds obtained in considering the overall service curve are better than considering each node individually (known as "*Pay burst only once*" phenomenon). + +The significance of the service curve is its ability to specify the service to be performed for a network element or a whole network, regardless of the type of buffer managements and scheduling mechanisms, and its ability to specify the concatenated behavior of a series of network elements or networks the user packet is to encounter. + +The detailed definition of the service curve is introduced in Appendix II. + +# **7 QoS architectural components** + +This Recommendation is based on the architectural components in [ITU-T Y.1291]. These architectural components are overviewed in this clause, the details being articulated in [ITU-T Y.1291]. + +This clause includes required enhancements for VPN applications to the architectural components presented in [ITU-T Y.1291]. + +### **7.1 Data plane architectural components** + +In this subclause, the architectural components for the data plane are considered. + +#### **7.1.1 Queue (or buffer) management** + +Queue or buffer management has been discussed in [ITU-T Y.1291], emphasizing various discard mechanisms when the queue is close to its capacity. + +[ITU-T Y.1291] provides details for queue or buffer management. No special need has been recognized in the VPN environment regarding those components. + +#### **7.1.2 Congestion avoidance** + +Congestion can occur either inside the VPN, when network resources are partitioned and dedicated to the VPN, or inside the network when the resources are not partitioned. When congestion is detected, the congestion avoidance function may need to be triggered. + +[ITU-T Y.1291] provides details for congestion avoidance. + +#### **7.1.3 Queuing and scheduling** + +Various queuing and scheduling mechanisms have been discussed in [ITU-T Y.1291], such as weighted fair queuing, priority queuing, and class-based queuing. Given the details that have been presented in [ITU-T Y.1291], no special requirements have been identified in the VPN environment. + +#### **7.1.4 Packet marking** + +Packet marking indicates the discard priority of the packet. It may be performed by the host, CEs, and PEs. The marking may be propagated inside the customer's network or the provider's network. + +[ITU-T Y.1291] provides details for packet marking. + +#### **7.1.5 Traffic classification** + +Traffic classification classifies the traffic into different queuing priorities. + +[ITU-T Y.1291] provides details for traffic classification. + +Packets of different VPNs or even in the same VPN may have different forwarding rules. The service provider selects forwarding rules via the traffic classification functions. Forwarding rules can be controlled and negotiated by the control plane. + +#### **7.1.6 Traffic policing** + +Traffic policing deals with the determination of whether the traffic being presented is compliant with the pre-negotiated policies or contracts. Typically non-conformant packets are dropped. The senders may be notified of the dropped packets and cause. + +The traffic is policed at the ingress of the network in accordance with the input characteristics outlined in clause 6.1. Even though a wide variety of the arrival curves may be used, only the token bucket arrival curve, shown in Figure 6-1, can be easily implemented at this time. + +[ITU-T Y.1291] provides details for the traffic policing function. + +#### **7.1.7 Traffic shaping** + +Traffic shaping deals with controlling the VPN traffic profile. The traffic shaper at the ingress point of the network is responsible for traffic shaping, and buffers the non-compliant packets until they are in compliance with the required traffic ingress characteristics. + +Traffic shaping often needs to be performed between ingress PEs and egress PEs. The traffic shapers may also need to be installed in the inter-provider boundaries. The location of the traffic shaper is at the discretion of service providers. + +### **7.2 Control plane architectural components** + +In this clause, the architectural components for the control plane are considered. The control plane architectural components of [ITU-T Y.1291] are not VPN aware. In order to control the VPN properly, some enhancements to [ITU-T Y.1291] control plane components are proposed in this subclause. + +#### **7.2.1 Resource manager** + +The resource manager includes the "resource reservation" architectural component of [ITU-T Y.1291]. + +The resource manager manages the resources for a set of node(s). The set can range from a single node to the whole network. + +The resource manager component may interact with many network elements involved in VPN so as to collect comprehensive network resource information. + +Users inside a network may be partitioned into different resource acquisition priorities, with high priority users to acquire the potentially contentious resources at the cost of low priority users. It is the resource manager's responsibility to properly coordinate the resources and its users. + +The customer network and provider network may both have their resource managers. Those resource managers control and manage the resources in customer networks and provider networks respectively, and they can communicate with each other to exchange customer network and provider network resource information, which is in order to guarantee CE-to-CE (customer edge-to-customer edge) QoS. + +The resource manager is an extension of the "resource reservation" architectural component of [ITU-T Y.1291] for the VPN environment. + +#### **7.2.2 Admission control** + +In the established network with a fixed quantity of resources, it is impossible to admit infinite VPN service instances with strict QoS requirements, so only a limited number of these VPN service instances with QoS requirements can be admitted into the network. This function is achieved by an admission control building block. The admission control will use the resource information provided by the resource manager. + +#### **7.2.3 VPN QoS routing** + +QoS routing mechanisms, introduced in [ITU-T Y.1291], need to support the VPN environment, and VPN topology. QoS routing may also be resource aware and use the resource information to increase the probability of successful resource reservation. + +This architectural component interacts with the resource manager to distribute the resource utilization information and to perform the path computation, with consideration of routing policies. + +Inter-layering QoS routing is not a VPN specific topic. While it is still in its infancy, the inter-layering QoS routing is out of the scope of this Recommendation. + +### **7.3 Management plane architectural components** + +The architectural components for the management plane are discussed in this clause. + +#### **7.3.1 Service level agreement management** + +A service level agreement (SLA) typically represents the agreement between a VPN customer and VPN provider that specifies the level of availability, serviceability, performance, operation or other attributes of that VPN service. It may include aspects such as pricing that are business in nature. In [b-RFC 3198] the technical part of the agreement is called the service level specification (SLS), which specifically includes a set of parameters and their values that together define the service offered to the VPN customer's traffic by the VPN provider's network. + +Both QoS service models (pipe and hose) can be expressed in the SLS. SLAs should cover the single provider case and multiple provider case. In the latter scenarios, the QoS parameters may be partitioned among the service providers. + +#### **7.3.2 Traffic measurement** + +Traffic metering in VPN concerns monitoring of the temporal properties (e.g., rate) of VPN traffic stream against the agreed traffic profile. It involves observing traffic characteristics at a given network point and collecting and storing the traffic information for analysis and further action, such as the validation and verification of the QoS guarantee level. + +It has to be noted that, in the various VPN service environments, traffic metering is not always possible. For VPNs using the hose model, the measurement on the CE-PE link can be performed. For point-to-point VPN traffic, measurement may be feasible at certain locations along the path of the flow. + +### **7.4 Enhancements for Y.1291** + +There are two architecture components which require enhancements in order to provide QoS properly under the VPN environment: + +- 1) Resource manager discussed in clause 7.2.1: the resource manager needs to be VPN aware so the collected data can be processed accordingly. +- 2) Traffic manager discussed in clause 7.3.2: the traffic manager needs to be VPN aware so the collected data can be processed accordingly. + +## **8 VPN service based on the pipe model** + +In this clause, the pipe model used in VPN will be investigated. The pipe model is to ensure QoS on a point-to-point connectivity basis. + +### **8.1 Definition of pipe model** + +The VPN customer specifies QoS requirements and/or assurances on each path between the VPN endpoints. At any given ingress point, if the customer needs to reach $n$ locations, the QoS requirement for each of those $n$ paths needs to be specified. + +For each pair of VPN endpoints, the network provider needs to provide adequate service bandwidth (i.e., adequate service curve) along the path of each pipe to ensure that the QoS is satisfied. Resources made available to the pipe cannot be allocated to other traffic. + +The customer should shape the traffic on CE delivered to the service provider on a per destination basis to avoid violation of the QoS agreement (e.g., see Figure 8-2 for details). A graphical illustration of the pipe model is shown in Figure 8-1. + +![Figure 8-1: Illustration of pipe model. The diagram shows a network topology where traffic flows from left to right. On the left, a Customer Edge (CE) node connects to a Virtual Forwarder (VF) node. This VF node connects to three intermediate nodes: a top VF, a central P node, and a bottom VF. Each of these three intermediate nodes connects to a VF node on the right, which then connects to a CE node. The connections between the left VF and the three intermediate nodes, and between the three intermediate nodes and the right VF, are labeled 'Pipe'. The central P node is connected to the top and bottom VF nodes. The top and bottom VF nodes are also connected to the right VF node. The CE nodes are connected to their respective VF nodes.](33ed1f9b27c7c21c797aa928b0f06851_img.jpg) + +Figure 8-1: Illustration of pipe model. The diagram shows a network topology where traffic flows from left to right. On the left, a Customer Edge (CE) node connects to a Virtual Forwarder (VF) node. This VF node connects to three intermediate nodes: a top VF, a central P node, and a bottom VF. Each of these three intermediate nodes connects to a VF node on the right, which then connects to a CE node. The connections between the left VF and the three intermediate nodes, and between the three intermediate nodes and the right VF, are labeled 'Pipe'. The central P node is connected to the top and bottom VF nodes. The top and bottom VF nodes are also connected to the right VF node. The CE nodes are connected to their respective VF nodes. + +Y1315(06)\_F8-1 + +**Figure 8-1 – Illustration of pipe model** + +In the above diagram, VF stands for virtual forwarder (VF), which contains the VPN-specific forwarding information, such as the VPN-based routing tables for IP VPNs. + +A pipe may be constructed via RSVP signalling if QoS assurance is to be ensured or via relative priority if over-provisioning is practiced. There are two means to pin down the routes of the packets: one is via the connection-oriented mechanisms such as MPLS, while the other is to use source routes in the connectionless realm. The details of pipe construction, maintenance, and deletion are out of the scope of this Recommendation. + +### 8.2 Customer edge characteristics + +In order to support the pipe model, and in order to ensure QoS, for each destination, the CE may need to shape the traffic in accordance with the SLA (or input characteristics). Failing to perform such per-destination shaping may result in the violation of the agreed upon QoS assurance. + +It should also be noted that, due to the dynamic nature of the packet routing, such per-destination-based shaping may not always be feasible. For example, a certain VPN user's address may change egress location on the provider's network due to routing table or routing policy modifications. + +### 8.3 Provider equipment characteristics + +In the PE, for each far-end destination, a policer (Figure 8-2) is required to ensure input traffic conformance. For the conforming traffic, with proper provisioning of the network resources, the QoS specified in the SLA can be ensured. + +Based on the SLA, the non-conforming traffic may be tagged with higher discard probability or be discarded. + +If the network provider has to provide the pipe model for VPN, there will be one policer per far-end destination on the ingress node to enforce the arrival curve. The network ingress point can be illustrated as in Figure 8-2. + +![Diagram of the Pipe model and traffic ingress policing. A central 'Provider's network' contains four 'PE' (Provider Edge) nodes and three 'P node' (Policer) nodes. Each PE node is connected to a 'CE' (Customer Edge) node. The CE nodes contain 'Shaper dest' blocks (e.g., Shaper dest 1, 2, 3, 4). The PE nodes contain 'Policer dest' blocks (e.g., Policer dest 1, 2, 3, 4). The P nodes are connected to the PE nodes, indicating traffic ingress policing at the edge of the provider's network. The diagram is labeled Y.1315(06)_F8-2.](fa859e4e468bfb2710a94527f2c504af_img.jpg) + +Diagram of the Pipe model and traffic ingress policing. A central 'Provider's network' contains four 'PE' (Provider Edge) nodes and three 'P node' (Policer) nodes. Each PE node is connected to a 'CE' (Customer Edge) node. The CE nodes contain 'Shaper dest' blocks (e.g., Shaper dest 1, 2, 3, 4). The PE nodes contain 'Policer dest' blocks (e.g., Policer dest 1, 2, 3, 4). The P nodes are connected to the PE nodes, indicating traffic ingress policing at the edge of the provider's network. The diagram is labeled Y.1315(06)\_F8-2. + +**Figure 8-2 – Pipe model and traffic ingress policing** + +Because there is no further traffic aggregation inside the network for the conforming customer traffic, it is relatively simple to deliver the required QoS, characterized by packet delay, delay variation, and packet loss. + +### 8.4 Applicability, complexity, and scalability + +In this clause, the applicability, complexity, and scalability of the pipe VPN are addressed. + +Applicability of the pipe VPN outlines the strength and limitations of this type of VPN. From the PE's perspective, each VPN's far endpoint requires a policer on the UNI (user to network interface) for non-BE traffic for traffic conformance purposes (known as arrival curve conformance). Furthermore, the policers are normally shared among a number of VPNs and the number of those policers is limited. In this case, the construction or augmentation (i.e., adding more endpoints) for a pipe VPN can only be carried out if and only if there are enough policers to enforce the traffic conformance. + +Because the VPN traffic policing is performed at the edge, packet discard due to policer action only relates to the underlying UNI, and not relate to the activities on other UNIs, as compared to the hose model discussed in clause 9.4. It is sometimes possible to have the CE shape the traffic so that packet loss due to policer action can be avoided. + +Network complexity discusses the issues related to VPN construction, deletion, and maintenance. For the VPNs based on the pipe model, the construction of the VPN involves construction of new pipes, resize or reuse of the existing pipes, along with the required resource reservation, so the VPN endpoints are fully connected with the desired QoS parameters. VPN deletion triggers the release of the resources and the pipe usage, with the possibility of pipe removal. The maintenance of the pipe VPN is to manage the pipes inside the network properly so that the VPN endpoints are fully connected with the desirable QoS parameters. + +The scalability of the pipe VPN is limited by the availability of policers and network processing power in managing the VPN. Because a large number of pipes are expected to exist inside the network, the size of the VPN is also limited by the resources at the physical interface and the underlying technology used to construct the VPN. It should be noted that the above statement is + +universally true but, due to the special nature of the VPN based on the pipe model ( $n$ square connectivity), the network resource usage at the physical interfaces will be taxed to the maximum. + +Due to the above-mentioned rationale, the pipe VPN will be applicable if the number of endpoints is small to moderate, and there is QoS assurance beyond BE traffic. + +### **8.5 Constructing the VPN based on the pipe model** + +The pipe model can be constructed via Diffserv or Intserv technology. There are two means to initiate a pipe request: via the CE action, or via the network management action. + +The construction procedure can be described by the following three procedures: request for creating a pipe, re-sizing a pipe, and request for destroying a pipe. + +The construction of a pipe can be summarized as follows: + +- 1) The CE or the network management system sends a request for creating a pipe service via the management plane or the control plane to the ingress PE, including QoS parameters such as bandwidth, delay, packet loss probability, etc. +- 2) If it is CE-initiated operation, authentication and verification procedures need to be performed but are out of the scope of this Recommendation. +- 3) The management plane or the control plane of the ingress PE receives the request and performs the following tasks: + - a) Ensures that the end-to-end reservations can be made, via control plane or management plane operations. The creation of the pipe will result in failure if end-to-end reservations cannot be ensured. + - b) Performs various edge functions, including but not limited to, traffic classification, marking, and policer programming. + +Similar to that of the pipe construction, the pipe deletion procedure can be described as follows: + +- 1) The CE or the network management system sends a request for destroying a pipe to the management or the control plane of the ingress PE. +- 2) The ingress PE ensures that the end-to-end reservation for this particular pipe is not in effect for the given VPN. +- 3) The ingress PE removes the required configuration, such as traffic classification, marking, and policer programming. + +The resize operation for an existing pipe is similar to that of the pipe creation (with minor modifications) and is not repeated in this Recommendation. If the resize operation results in a failure, the existing VPN pipe configuration should not be impacted. + +## **9 VPN service based on the hose model** + +In this clause, the hose model used in VPN is investigated. The hose model is to ensure QoS on a point-to-cloud connectivity. + +### **9.1 Definition of hose model** + +The VPN customer specifies QoS requirements per VPN endpoint and not per every pair of endpoints. Specifically, associated with each endpoint, there is a pair of bandwidth values – an ingress bandwidth and an egress bandwidth. The ingress bandwidth for an endpoint specifies the incoming traffic from all the other VPN endpoints into the endpoint, while the egress bandwidth is the amount of traffic the endpoint can send to the other VPN endpoints. + +The hose model (see Figure 9-1) is easy to provision for the customer and no destination sensitive customer traffic shaping is required. The challenge for the service provider is to provision adequate resources at the traffic aggregation points inside the network. + +![Figure 9-1: Illustration of hose model. The diagram shows a network topology with Customer Edges (CE), Provider Edges (PE), Virtual Forwarders (VF), and Merge Points (M). Traffic flows from CE to PE, then through VF to a P node, which then flows to another P node and finally to a PE with a Merge Point (M) before reaching the destination CE. The diagram illustrates how traffic from multiple VPNs is aggregated at a merge point within the network.](ff7ce44f3fdd51bae7b231f34df07c6a_img.jpg) + +Y1315(06)\_F9-1 + +Figure 9-1: Illustration of hose model. The diagram shows a network topology with Customer Edges (CE), Provider Edges (PE), Virtual Forwarders (VF), and Merge Points (M). Traffic flows from CE to PE, then through VF to a P node, which then flows to another P node and finally to a PE with a Merge Point (M) before reaching the destination CE. The diagram illustrates how traffic from multiple VPNs is aggregated at a merge point within the network. + +**Figure 9-1 – Illustration of hose model** + +As in the pipe model, VF stands for virtual forwarder which contains VPN-specific forwarding information. Inside the network, on some P nodes or PEs, there can be a merge point for that VPN (denoted by M in the above illustration). The SLA enforcement and scheduling of the aggregated packet flows for that VPN need to be supported at the merging point. + +The major difference between the pipe and hose model is that, in the hose model, traffic aggregation happens inside the network. In the pipe model, there is no traffic aggregation inside the network. Hence, in the pipe model, it is not possible to share the resources inside the network among different VPN endpoints. + +A hose may be constructed via signalling if QoS assurance is to be ensured or via relative priority if over-provisioning is practiced. In order to construct the hose with QoS assurance, the merge point, which can be at a P node, is required to have policers so the traffic from one VPN does not have a negative impact on the network. The details of hose construction, maintenance, and deletion are out of the scope of this Recommendation. + +### 9.2 Customer edge characteristics + +In order to limit the traffic into the network within the bounds established via SLA, the CE needs to shape the traffic on the CE-to-PE link. Compared to that of the pipe model, the shaping for the hose model is not destination sensitive. The CE is then simpler as far as the traffic shaping is concerned. + +### 9.3 Provider equipment characteristics + +At the CE-to-PE link, the traffic policer on the PE is not per-destination based. Only the aggregated traffic needs to be policed based on the SLA. + +If there are aggregation points inside the network, in order to ensure QoS and SLA conformance, proper resources need to be allocated. + +There are a few issues related to the hose model: + +- If a packet is discarded at the aggregation point inside the network based on the SLA (e.g., total VPN bandwidth is limited to a certain amount, regardless of the source of such traffic), such discards will be random and the application performance may be at risk of being poor (e.g., some applications may be more sensitive to packet loss). + +- Due to the lack of per-flow reservation, and if there is no policer/shaper on the PE-to-CE link, the PE-to-CE link may be congested and hence result in packet loss. This case may be more pronounced if multiple CEs are sending traffic to a single CE. While each CE is sending traffic within its agreed-upon limit, the egress of the network, on the PE-to-CE link, will be overwhelmed. + +If the network provider has to provide the hose model, the provider requires only one policer at the ingress of the network, as shown in Figure 9-2. + +![Figure 9-2: Hose model ingress policing and network implications. The diagram shows three Customer Edge (CE) nodes on the left, each containing a 'Shaper' box. These are connected via 'Customer access (VPN-A)' links to three Provider Edge (PE) nodes on the right. Each PE node contains a 'Policer user traffic' box. The PE nodes are part of a larger 'Provider's network' oval. Traffic from the PE nodes is aggregated at 'P node' boxes, labeled 'Traffic aggregate for the same VPN user'. Arrows indicate traffic flow from CEs to PEs and then to P nodes. A reference code 'Y.1315(06)_9-2' is in the bottom right corner.](2b3a967f6ce4f23649be995a353e39f8_img.jpg) + +Figure 9-2: Hose model ingress policing and network implications. The diagram shows three Customer Edge (CE) nodes on the left, each containing a 'Shaper' box. These are connected via 'Customer access (VPN-A)' links to three Provider Edge (PE) nodes on the right. Each PE node contains a 'Policer user traffic' box. The PE nodes are part of a larger 'Provider's network' oval. Traffic from the PE nodes is aggregated at 'P node' boxes, labeled 'Traffic aggregate for the same VPN user'. Arrows indicate traffic flow from CEs to PEs and then to P nodes. A reference code 'Y.1315(06)\_9-2' is in the bottom right corner. + +**Figure 9-2 – Hose model ingress policing and network implications** + +The hose model is simple for the customer to configure the traffic, and simple for the network provider at the ingress node. But, in order to provide the required QoS, the provider needs to ensure that, at the traffic aggregation points, the customer traffic is properly handled. + +### 9.4 Applicability, complexity, and scalability + +From the PE's perspective, each VPN only requires one policer at the UNI. Hence the hose models are normally not limited by the number of policers at the UNI, as with the pipe model discussed in clause 8.4. + +If the VPN bandwidth is to be monitored to ensure QoS and fairness, the aggregation (or merge) points inside the network (P nodes) for the hose model also require a policer. This dictates that the policer be installed not at the UNI. The policer on the P node also requires that packets carry VPN information, either implicitly or explicitly. + +Due to its location not at the UNI, the policer may discard packets at that location as a result of packets received at different UNIs. Such inter-UNI interference is very undesirable since each UNI is acting independently and there is no CE action which can prevent such packet loss. + +In terms of total policer usage, the hose model is less than or equal (when two flows from UNI are merged only once) to the pipe model. + +In terms of network complexity, adding or deleting a VPN endpoint does not trigger network reconfiguration at the UNI, but may trigger the network-wide reconfiguration due to a possible merge-point change. The scope of network nodes affected for bandwidth reservation purposes is less than or equal to that of the pipe model, with the worst case being equal. + +The scalability of the hose model is limited by the policers at the merge points (not at the UNI as that of the pipe model). The hose model may require less computing power when the bandwidth reservation needs to be changed (i.e., adding or removing an endpoint). + +Due to the above rationale, the hose VPN is applicable if the number of VPN endpoints is large, and there is QoS assurance. Besides, packet loss does not result in a critical error because it is impossible for CEs to coordinate so traffic can be shaped properly at the merge points. + +Even though it is possible for the hose model to support a very large number of VPN endpoints, the management of the merging points is difficult. In this sense, the hose model is best used when there is no QoS assurance in the SLA (CoS differentiation is acceptable). + +# 10 VPN service based on both pipe and hose model + +For any given provider's network, both pipe and hose model can be used to construct VPNs. A pipe model-only VPN may be constructed provided the conditions to construct the pipe model are satisfied (clause 8.4). The same statement can also apply to the hose model (with the hose model pre-requisites discussed in clause 9.4). + +When both the hose and pipe models are offered, the service provider's equipment and management system needs to endure the complexity of both models. + +If some segments of the VPN are constructed via the pipe model while other segments are constructed via the hose model, as shown in Figure 10-1, the general characteristics of the VPN is that of the hose model, excepted for the flows not going through the hose section of the VPN. + +![Diagram illustrating a VPN structure combining both pipe and hose models. Four nodes (A, B, C, D) are arranged in a circle. A central oval labeled 'Hose' is connected to all four nodes. The connections from A and B to the 'Hose' oval are shown as straight lines, representing the pipe model. The connections from C and D to the 'Hose' oval are shown as curved lines, representing the hose model. The entire structure is enclosed in a light blue oval. The label 'Y.1315(06)_F10-1' is located at the bottom right of the diagram.](e636d7ccca0ad14c6b95201404324823_img.jpg) + +Y.1315(06)\_F10-1 + +Diagram illustrating a VPN structure combining both pipe and hose models. Four nodes (A, B, C, D) are arranged in a circle. A central oval labeled 'Hose' is connected to all four nodes. The connections from A and B to the 'Hose' oval are shown as straight lines, representing the pipe model. The connections from C and D to the 'Hose' oval are shown as curved lines, representing the hose model. The entire structure is enclosed in a light blue oval. The label 'Y.1315(06)\_F10-1' is located at the bottom right of the diagram. + +**Figure 10-1 – Combining both pipe and hose model in the same VPN** + +The base VPN model can be a hose model, which reduces the complexity of the VPN management, especially if no QoS assurance is involved. For flows dictating QoS treatment, a pipe can be used between the flow endpoints. + +In the case shown in Figure 10-1, a VPN will use the combination of both QoS models. For basic connectivity with CoS (class of service), the hose model can be deployed for simplicity (there will be no policing at the traffic merging points). For flows dictating QoS assurance, a pipe can be used. Hence the benefits of both the pipe model and the hose model can be materialized. + +In particular, there is no need to have a large number of policers at the UNI points (not proportional to the number of endpoints of a given VPN), and there is no need to have policers at merge points. Of course, this is under the assumption that only a fraction of flows dictates QoS assurance. + +# 11 Multiple service provider scenario + +If a VPN service is provided via multiple VPN service providers, the overall service characteristics (i.e., service curve) can be obtained via the service curve of each provider (i.e., concatenation of service curves for each service provider). + +One of the advantages of using the service curve to specify the service is its ability to work in the multiple service provider case. If each service provider's network is abstracted as an abstract node, offering service curve $\beta_i(t)$ and if the customer's packet is traversing $N$ service providers, the effective service curve from the customer's point of view will be: + +$$\beta(t) = \beta_1(t) \otimes \beta_2(t) \otimes \dots \otimes \beta_N(t) \quad (1)$$ + +If a policer is employed between two service providers, the arrival curve for traffic delivered from service provider $i$ to service provider $i+1$ will be: + +$$\alpha^*_i(t) = \alpha(t) \otimes (\beta_1(t) \otimes \dots \otimes \beta_i(t)) \quad (2)$$ + +There are many types of multiple service provider scenarios. In this clause, only the basic scenario with two service providers is illustrated. More complex configurations can be brought back to the basic configuration. It should be noted that there are multiple forms of inter-provider QoS arrangements and what is outlined in this clause is not meant to be exclusive. + +The basic configuration of a multiple service provider scenario is the cascade of two service providers, as shown below in Figure 11-1. + +![Figure 11-1: Multiple service provider scenario. The top part shows a diagram of two service providers, A and B, connected in series. The bottom part shows three graphs illustrating the convolution of service curves. The first graph, 'Service curve A', shows a linear curve with slope alpha and a delay tau. The second graph, 'Service curve B', shows a linear curve with slope beta and a delay sigma. The third graph, 'Convolved service curve', shows the resulting linear curve with slope beta and a total delay of tau + sigma. The graphs are connected by a convolution symbol (⊗) and an equals sign (=).](bd4617f25d15430eb78c2d6d75a99dde_img.jpg) + +Y.1315(06)\_F11-1 + +Figure 11-1: Multiple service provider scenario. The top part shows a diagram of two service providers, A and B, connected in series. The bottom part shows three graphs illustrating the convolution of service curves. The first graph, 'Service curve A', shows a linear curve with slope alpha and a delay tau. The second graph, 'Service curve B', shows a linear curve with slope beta and a delay sigma. The third graph, 'Convolved service curve', shows the resulting linear curve with slope beta and a total delay of tau + sigma. The graphs are connected by a convolution symbol (⊗) and an equals sign (=). + +**Figure 11-1 – Multiple service provider scenario** + +In this case, the slope introduced in the service curve will be the minimum slope of the two providers' service curves while the delay will be additive. + +If a VPN service is provided by multiple service providers with a linear service curve (characterized by a delay and a slope), the overall service curve perceived by the VPN user will also be linear, with the slope to be the minimum of all these service curves, and the delay to be the sum of all delays introduced by these service curves. + +# Appendix I + +## Pipe model-based implementation example of VPN with specific QoS requirements + +(This appendix does not form an integral part of this Recommendation) + +### I.1 Service requirements + +Service providers have established their L3 VPNs based on [b-RFC 2547] and have started to provide L2 VPNs to their customers based on IETF L2 VPN WG drafts. Based on the operators' experience, a customer purchases L2 or L3 VPN services to connect his multiple sites at the corresponding layer. The service provider will ensure that traffic proper to a specific VPN does not trespass on other VPNs. Some VPNs may have topology constraints (e.g., hub-spoke). + +Service providers have a practical need to build a unified network which is capable of providing L2 and L3 VPNs simultaneously. Some basic requirements of such a unified VPN network are as follows: + +- 1) Support controllable route distribution – From the point of view of providers, VPN membership information (the sites belonging to the same VPN) and VPN reachability among sites should be controllable in flexible way and manageable in effective way. +- 2) Support multiple address types and overlapping address spaces (for different VPNs) – The "unified VPN" network should support both L2 and L3 VPNs, including L2 address types (e.g., FrameRelay (DLCI), ATM (VPI/VCI), and Ethernet (IEEE 802 MAC address and VLAN) address types) and L3 address types (IPv4 and IPv6). +- 3) Support end-to-end QoS – The MPLS technology has been widely accepted in the providers' backbone infrastructure, hence a practical strategy is to combine the MPLS QoS tools (e.g., TE, Diffserv) with the unified VPN architecture. + +### I.2 Unified QoS-VPN architecture + +"QoS-VPN" implies a VPN with QoS requirements, including bandwidth, delay, jitter, packet loss rate among sites belonging to the VPN. The centralized QoS architecture listed in Appendix I of [ITU-T Y.1291] can be used to construct a unified QoS-VPN network. The QoS-VPN architecture can be divided into three layers: VPN service control layer, VPN transport layer, VPN transport control layer. In this architecture, MPLS is used in the transport network. + +VPN transport control layer consists of VPN-CRCs, one for each VPN domain. The VPN-CRC (central router controller) corresponds to the BRM (bearer resource manager) layer depicted in [ITU-T Y.1291]. The typical VPN domain is an autonomous system in the current IP network. A VPN-CRC performs the following functions: + +- Manages the network resources (including bandwidth, processor, and buffer) of a VPN-LBN (VPN-logical transport network); +- Maintains the VPN-LBN network topology; +- Performs path selection and then path information instruction to the ingress PE; +- Performs resource allocation and admission control within a VPN-LBN; +- Maintains membership and reachability information at a per QoS-VPN level; +- Performs related signalling to achieve membership auto-discovery and single-sided provisioning. + +Diffserv-aware MPLS technology is used to process the different VPN flows belonging to the same PE-to-PE pipe. + +The generic LSP label stack with three layers is used: TE tunnel outer label, VPN label, and flow label. The top label is the MPLS TE tunnel label with all the micro-flows inside which have the same QoS requirement. The VPN label, together with the flow label, identifies the source and the destination of the packet. + +Figure I.1 shows an implementation example of the unified QoS-VPN architecture in one single AS (autonomous system). + +![Figure I.1: Implementation example of the unified QoS-VPN in one single AS. The diagram illustrates a network architecture within a single Autonomous System. At the top, a triangle labeled 'VPN-SCS' is connected to a cylinder labeled 'VPN-CRC'. An arrow points to the VPN-CRC with the text 'VPN request from VPN site or from public Internet'. Below this control layer is a large oval representing the AS network. Inside the oval, there are two smaller dashed ovals: 'L3 VPN TR cluster' (top) and 'L2 VPN TR cluster' (bottom). Various nodes (circles) are positioned around the perimeter and inside the clusters. L3 VPN sites and L2 VPN sites are connected to these nodes. Dotted and dashed arrows represent TE tunnels: 'L3 VPN TE tunnel ER to TR direction', 'L3 VPN TE tunnel TR to ER direction', 'L2 VPN TE tunnel ER to TR direction', and 'L2 VPN TE tunnel from TR to ER direction'. A large grey arrow at the bottom indicates 'VPN flow example from VPN site left side to right side'. The diagram is indexed as Y.1315(06)_FI.1.](d734a6ea1b381280f043fcf70391b6db_img.jpg) + +Figure I.1: Implementation example of the unified QoS-VPN in one single AS. The diagram illustrates a network architecture within a single Autonomous System. At the top, a triangle labeled 'VPN-SCS' is connected to a cylinder labeled 'VPN-CRC'. An arrow points to the VPN-CRC with the text 'VPN request from VPN site or from public Internet'. Below this control layer is a large oval representing the AS network. Inside the oval, there are two smaller dashed ovals: 'L3 VPN TR cluster' (top) and 'L2 VPN TR cluster' (bottom). Various nodes (circles) are positioned around the perimeter and inside the clusters. L3 VPN sites and L2 VPN sites are connected to these nodes. Dotted and dashed arrows represent TE tunnels: 'L3 VPN TE tunnel ER to TR direction', 'L3 VPN TE tunnel TR to ER direction', 'L2 VPN TE tunnel ER to TR direction', and 'L2 VPN TE tunnel from TR to ER direction'. A large grey arrow at the bottom indicates 'VPN flow example from VPN site left side to right side'. The diagram is indexed as Y.1315(06)\_FI.1. + +**Figure I.1 – Implementation example of the unified QoS-VPN in one single AS** + +In order to improve the scalability of practical deployments, the concept of VPN central control cluster (CCC) system may be introduced (not indicated in Figure I.1). The main function of VPN central control cluster (CCC) is to achieve VPN resource isolation with the use of trunk TE tunnels between ingress trunk routers and egress trunk routers. These trunk ingress and egress routers form the trunk router cluster for a particular VPN service. + +In the inter-AS scenario, VPN-LBN resources can be planned and managed according to the different AS. In this case, TE tunnels are initiated and terminated within the AS. In order to ensure the end-to-end QoS of a VPN service flow, there should be a mechanism to link the different TE tunnel segments. + +### I.3 Considerations + +In this architecture, the PE supports upstream and downstream TE tunnel set-up through RSVP-TE/CR-LDP and traffic classification. The number of upstream and downstream TE tunnels is not of the order of $n^2$ where $n$ is the number of PEs inside the network due to the traffic tunnel construction. + +The key objective of this implementation example is to reduce the features required to be supported inside the PE and to improve the scalability and upgrade ability of the PE. + +With this architecture, the PE can be manually configured and performs the functions of VPN flow identification, label binding, and VPN admission control. The network resource allocation and reservation is carried out by the logical central trunk clusters. This implementation example can provide both L3 VPN and L2 VPN services and with stringent QoS requirements. Further details on the protocols between PE to CRC, TR to CRC, and CRC to CRC are out of the scope of this Recommendation. + +# Appendix II + +## Service curve + +(This appendix does not form an integral part of this Recommendation) + +Consider the input function $R(t)$ (cumulative bits input into the network) and the output function $R^*(t)$ (cumulative bits output from the network), the "service curve" $\beta(t)$ offered by the service provider will be defined as: + +$$R^*(t) \geq R(t) \otimes \beta(t) \quad (\text{II-1})$$ + +where the symbol $\otimes$ denotes the min-plus convolution and can be defined as: + +$$R(t) \otimes \beta(t) = \inf_{s \leq t} \{R(s) + \beta(t-s)\} \quad (\text{II-2})$$ + +For a constant bit rate service, the service curve will then be defined as $\beta(t) = rt + t_0$ where $t_0$ denotes the initial delay in serving the packets. + +For a flow, constrained by arrival curve $\alpha(t)$ , traversing a system that offers a service curve of $\beta(t)$ , the output flow will be constrained by the arrival curve $\alpha^*(t)$ , with $\alpha^*(t)$ expressed as (min-plus deconvolution): + +$$\alpha^*(t) = \alpha(t) \otimes \beta(t) = \sup_{u \geq 0} (\alpha(t+u) - \beta(u)) \quad (\text{II-3})$$ + +For a flow traversing $N$ nodes (networks), while each node (network) offering a service curve $\beta_{n_i}(t)$ , the service curve, after the nodal concatenation, will be: + +$$\beta_{C_N}(t) = \beta_{n_1}(t) \otimes \beta_{n_2}(t) \otimes \dots \otimes \beta_{n_N}(t) \quad (\text{II-4})$$ + +The arrival curve after traversing those $N$ nodes will be: + +$$\alpha^*(t) = \alpha(t) \otimes \beta_{C_N}(t) \quad (\text{II-5})$$ + +# Bibliography + +- LE BOUDEC (J.Y.), THIRAN Patrick, *"Network Calculus"*, Springer, 2001. +- CHUANG (J.-F.), CHANG (C.-M.), *"Deterministic loss ratio quality of service guarantees for high speed networks"*, IEEE Communications Letters 4, pp. 236-238, 2000. +- CRUZ (R.), CHANG (C.S.), LE BOUDEC (J.-Y.), and THIRAN (P.), *"A min-plus system theory for constrained traffic regulation and dynamic service guarantees"*, Technical Report SSC/1999/024, EPFL, 1999. +- CRUZ (R.), and TANEJA (M.), *"An analysis of traffic clipping"*, In Proc. 1998 Conf. on Information Science & Systems, Princeton University, 1998. +- CRUZ (R.L.), *"A calculus for network delay, Part i: Network elements in isolation"*, IEEE Trans. Inform. Theory, Vol. 27-I pp. 114-131, 1991. +- CRUZ (R.L.), *"A calculus for network delay, part ii: Network analysis"*, IEEE Trans. Inform. Theory, Vol. 37-I, pp. 132-141, 1991. +- [b-ITU-T X.85] ITU-T Recommendation X.85/Y.1321 (2001), *IP over SDH using LAPS*. +- [b-IETF RFC 1661] IETF RFC 1661 (1994), *"The Point-to-Point Protocol (PPP)"*. +- [b-IETF RFC 2205] IETF RFC 2205 (1997), *"Resource Reservation Protocol (RSVP)"*. +- [b-IETF RFC 2215] IETF RFC 2215 (1997), *"General Characterization Parameters for Integrated Service Network Elements"*. +- [b-IETF RFC 2547] IETF RFC 2547 (1999), *"BGP/MPLS VPN"*. +- [b-IETF RFC 3198] IETF RFC 3198 (2001), *"Terminology for Policy-Based Management"*. + + + +# SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|--------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/Y/T-REC-Y.140-200011-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/Y/T-REC-Y.140-200011-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..8ef94232ad379b90f399cee36311d5cb51372601 --- /dev/null +++ b/marked/Y/T-REC-Y.140-200011-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:78f0625ff957c350eb0d5998c514cb05d4ee3d0c586c9a31ca291699e805dfe2 +size 8289 diff --git a/marked/Y/T-REC-Y.140-200011-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg b/marked/Y/T-REC-Y.140-200011-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..9d8522a8b43ea59f87a031ad4aa46746e2f6b9fd --- /dev/null +++ b/marked/Y/T-REC-Y.140-200011-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:c0cdc82fa2704a95f0486a0add1c081f885bba84602935c03779f659b848862d +size 65613 diff --git a/marked/Y/T-REC-Y.140-200011-I_PDF-E/41a438d7e4adc17c3a4005e7c9500091_img.jpg b/marked/Y/T-REC-Y.140-200011-I_PDF-E/41a438d7e4adc17c3a4005e7c9500091_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..ba97a63b0e147c46aed3f8b00ad94bf433ea9bdc --- /dev/null +++ b/marked/Y/T-REC-Y.140-200011-I_PDF-E/41a438d7e4adc17c3a4005e7c9500091_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:1dadb9da54151ec435aaacae99afeb75bb34b75eb0a91aeffa09e9166cc5e5f5 +size 61773 diff --git a/marked/Y/T-REC-Y.140-200011-I_PDF-E/4f148853ae68fdcf5e43f7604cab457d_img.jpg b/marked/Y/T-REC-Y.140-200011-I_PDF-E/4f148853ae68fdcf5e43f7604cab457d_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..300816007ff65ce738a3f8d452fd4883a8dcf512 --- /dev/null +++ b/marked/Y/T-REC-Y.140-200011-I_PDF-E/4f148853ae68fdcf5e43f7604cab457d_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:cd8af32322d18dd1cd971654765eb9279e971742a5d3d82fcdc710ee1ff98e6f +size 62548 diff --git a/marked/Y/T-REC-Y.140-200011-I_PDF-E/69b7bd65e85cdef6fdd7fb0a8194257c_img.jpg b/marked/Y/T-REC-Y.140-200011-I_PDF-E/69b7bd65e85cdef6fdd7fb0a8194257c_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..65ad8297efa5f7046f1570e87b688b2428d5c198 --- /dev/null +++ b/marked/Y/T-REC-Y.140-200011-I_PDF-E/69b7bd65e85cdef6fdd7fb0a8194257c_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:da1bb1de3132f8f42ad969826791869ddecf705dc78fca6b9ada66ce6d1e0282 +size 68826 diff --git a/marked/Y/T-REC-Y.140-200011-I_PDF-E/6f31cdb576d2f15c35c3f266e5f59211_img.jpg b/marked/Y/T-REC-Y.140-200011-I_PDF-E/6f31cdb576d2f15c35c3f266e5f59211_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..1ebf503bc7d6c97ca1760e65abeb4eb52c674261 --- /dev/null +++ b/marked/Y/T-REC-Y.140-200011-I_PDF-E/6f31cdb576d2f15c35c3f266e5f59211_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:8bbfed4b60a6202b670b1e8469c8192ecf17a867c6e61fe4a1fc05668027c731 +size 32471 diff --git a/marked/Y/T-REC-Y.140-200011-I_PDF-E/7133ccf78043568ca62ecbcd43628a4a_img.jpg b/marked/Y/T-REC-Y.140-200011-I_PDF-E/7133ccf78043568ca62ecbcd43628a4a_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..180f836519ee719df6ad68a4856efe31d08412b6 --- /dev/null +++ b/marked/Y/T-REC-Y.140-200011-I_PDF-E/7133ccf78043568ca62ecbcd43628a4a_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:f31549a2ddf491e820d0485a96c3dc99a22c9b292d24ab04a2fa23e5a0e2e63d +size 39410 diff --git a/marked/Y/T-REC-Y.140-200011-I_PDF-E/9cd90f495b95ad2116ff780248c26d95_img.jpg b/marked/Y/T-REC-Y.140-200011-I_PDF-E/9cd90f495b95ad2116ff780248c26d95_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..c560edb2cf1ac7da09ed579d3ed457c95813d640 --- /dev/null +++ b/marked/Y/T-REC-Y.140-200011-I_PDF-E/9cd90f495b95ad2116ff780248c26d95_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:e705d9ea5e1408f95761114ab0fd2d0838af1ab94039a1ac31c7819b95e4e863 +size 47717 diff --git a/marked/Y/T-REC-Y.140-200011-I_PDF-E/aaf3e6e44cdeabd6d1df869c5f392ea1_img.jpg b/marked/Y/T-REC-Y.140-200011-I_PDF-E/aaf3e6e44cdeabd6d1df869c5f392ea1_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..5a968dafdc6a1f1a2d492f0202f48adbe8f3e8bd --- /dev/null +++ b/marked/Y/T-REC-Y.140-200011-I_PDF-E/aaf3e6e44cdeabd6d1df869c5f392ea1_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:2f555d94681699d9a510d9763d44f172b5a9ed4cedda8787ba8ad0e912059965 +size 102629 diff --git a/marked/Y/T-REC-Y.140-200011-I_PDF-E/bd671b21db63e6fdb2196e9b18502aac_img.jpg b/marked/Y/T-REC-Y.140-200011-I_PDF-E/bd671b21db63e6fdb2196e9b18502aac_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..b5ba2ae387c15879f997f44116c5b9726c1991a8 --- /dev/null +++ b/marked/Y/T-REC-Y.140-200011-I_PDF-E/bd671b21db63e6fdb2196e9b18502aac_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:ea388d8dbd96cc78d3cdb057b6b1113c2e1fc2b5b5e8153b84560217bc93999e +size 45328 diff --git a/marked/Y/T-REC-Y.140-200011-I_PDF-E/c5655e700cc3e9aac7e9f4f07f30264d_img.jpg b/marked/Y/T-REC-Y.140-200011-I_PDF-E/c5655e700cc3e9aac7e9f4f07f30264d_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..b4b40784fbfaa17b2a97732376f3c0a2ed546419 --- /dev/null +++ b/marked/Y/T-REC-Y.140-200011-I_PDF-E/c5655e700cc3e9aac7e9f4f07f30264d_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:d11c70c4664ef1058dac0233e43fae78e6e17ca6d0c365fe73a78ba321495ff3 +size 72295 diff --git a/marked/Y/T-REC-Y.140-200011-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg b/marked/Y/T-REC-Y.140-200011-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..ab565bf97d273189884b4480899ea690d1969be5 --- /dev/null +++ b/marked/Y/T-REC-Y.140-200011-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:65635cebdbe5e75073203891eb486c6ed5ea512a08a57e0a5e8b4cedfa6095bc +size 216400 diff --git a/marked/Y/T-REC-Y.140-200011-I_PDF-E/dd5771673aececa53d42ece89218299d_img.jpg b/marked/Y/T-REC-Y.140-200011-I_PDF-E/dd5771673aececa53d42ece89218299d_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..5ac85042a8bf81c618f6c40561396f73c2f830a2 --- /dev/null +++ b/marked/Y/T-REC-Y.140-200011-I_PDF-E/dd5771673aececa53d42ece89218299d_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:c687e7c2ca966fba53894652b5cfe4baa503434ce945b75b06f6573122819f27 +size 30047 diff --git a/marked/Y/T-REC-Y.140-200011-I_PDF-E/e69b9188aa2c14ec6b21c83f711fef65_img.jpg b/marked/Y/T-REC-Y.140-200011-I_PDF-E/e69b9188aa2c14ec6b21c83f711fef65_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..402dd1c31ad7fe5638502641ee75573cc3855340 --- /dev/null +++ b/marked/Y/T-REC-Y.140-200011-I_PDF-E/e69b9188aa2c14ec6b21c83f711fef65_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:c0d84b6bb689cf19d19085b1fdd74bc893e9465a8f9caeb7975cf91876b785fc +size 70837 diff --git a/marked/Y/T-REC-Y.140-200011-I_PDF-E/e7c6a6e4c3047dac05a3b92e396e9794_img.jpg b/marked/Y/T-REC-Y.140-200011-I_PDF-E/e7c6a6e4c3047dac05a3b92e396e9794_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..9dae9e26330f0c5d0c85109f2c17520964a35e92 --- /dev/null +++ b/marked/Y/T-REC-Y.140-200011-I_PDF-E/e7c6a6e4c3047dac05a3b92e396e9794_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:fd6b1dab2decc1ab37216d4988c5aa8d60d0ea9fde636f409b23f2ac149c052b +size 32865 diff --git a/marked/Y/T-REC-Y.140-200011-I_PDF-E/eefe19c5e14dc4d6c316b7f7fbb7d7d7_img.jpg b/marked/Y/T-REC-Y.140-200011-I_PDF-E/eefe19c5e14dc4d6c316b7f7fbb7d7d7_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..ab394f52eeefc6e32f30129937326f0cd5f7fe09 --- /dev/null +++ b/marked/Y/T-REC-Y.140-200011-I_PDF-E/eefe19c5e14dc4d6c316b7f7fbb7d7d7_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:281af7b8793cdf6c72dca878299b2392378c7bdef933372e57565a3c91b8b272 +size 105867 diff --git a/marked/Y/T-REC-Y.140-200011-I_PDF-E/f0b7aaa539a2f77c98d53ed6c1c2366b_img.jpg b/marked/Y/T-REC-Y.140-200011-I_PDF-E/f0b7aaa539a2f77c98d53ed6c1c2366b_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..0f2483a6810c315e1dea8112ca1f7ed1daa7cbfd --- /dev/null +++ b/marked/Y/T-REC-Y.140-200011-I_PDF-E/f0b7aaa539a2f77c98d53ed6c1c2366b_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:7ba32c42f2b7474ac3cc07a4779238e406cc6a68add1f52e2b2982206637c6f4 +size 35915 diff --git a/marked/Y/T-REC-Y.1453-200603-I_PDF-E/042733dc5e8e7f5f30b60adba3266cde_img.jpg b/marked/Y/T-REC-Y.1453-200603-I_PDF-E/042733dc5e8e7f5f30b60adba3266cde_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..7b07243212ffdadfc7dc618c000f1bb017cff302 --- /dev/null +++ b/marked/Y/T-REC-Y.1453-200603-I_PDF-E/042733dc5e8e7f5f30b60adba3266cde_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:c585f72218bfa83fd10c9432bc82e85c52f793fca0998d04832e8ab31155dde4 +size 78551 diff --git a/marked/Y/T-REC-Y.1453-200603-I_PDF-E/18442e4e239480f0c3c95b547aa8fde2_img.jpg b/marked/Y/T-REC-Y.1453-200603-I_PDF-E/18442e4e239480f0c3c95b547aa8fde2_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..27b0cfbfa48eb53b00e0fc92be7f1d1a9c1e2016 --- /dev/null +++ b/marked/Y/T-REC-Y.1453-200603-I_PDF-E/18442e4e239480f0c3c95b547aa8fde2_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:045d83bb8418226aad45783d2bd2bd70a486051a5a2e0ce8d87a21e635e344ee +size 46900 diff --git a/marked/Y/T-REC-Y.1453-200603-I_PDF-E/26d664119ad25250780f554633444e54_img.jpg b/marked/Y/T-REC-Y.1453-200603-I_PDF-E/26d664119ad25250780f554633444e54_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..83bcccc1118ba8b6f60d49608cd2767f583dfa45 --- /dev/null +++ b/marked/Y/T-REC-Y.1453-200603-I_PDF-E/26d664119ad25250780f554633444e54_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:8283356976cdf395aa17a5880dda16130787a23c8c4d7a33a92ced0bdd986e64 +size 12858 diff --git a/marked/Y/T-REC-Y.1453-200603-I_PDF-E/2734e7f9be3e1dc046f14be2e6c9a085_img.jpg b/marked/Y/T-REC-Y.1453-200603-I_PDF-E/2734e7f9be3e1dc046f14be2e6c9a085_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..025c34a7154a4cb2c3dd2b708a4e297f6521bbc6 --- /dev/null +++ b/marked/Y/T-REC-Y.1453-200603-I_PDF-E/2734e7f9be3e1dc046f14be2e6c9a085_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:49d0e35fa6654bd7b4f9b4ad5af52273a8c6f47c33c95e9d0aecc6d93b5da3dd +size 26743 diff --git a/marked/Y/T-REC-Y.1453-200603-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg b/marked/Y/T-REC-Y.1453-200603-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..0baa735bbe61647f8890b7c002c1fd42a9e0e80f --- /dev/null +++ b/marked/Y/T-REC-Y.1453-200603-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:7994969a2ac9173f179d20c1b56966942dae0447ce4e9f8dd1de691e4ae21e53 +size 45988 diff --git a/marked/Y/T-REC-Y.1453-200603-I_PDF-E/5b8a756d9a71c35f17db8bcb90b438a3_img.jpg b/marked/Y/T-REC-Y.1453-200603-I_PDF-E/5b8a756d9a71c35f17db8bcb90b438a3_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..637f554bdbdbf6326dbfc055d1b24d89e867aca6 --- /dev/null +++ b/marked/Y/T-REC-Y.1453-200603-I_PDF-E/5b8a756d9a71c35f17db8bcb90b438a3_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:b230031bc7af297b144dbd6041c244a0ff040d76c7064559485e77135095076c +size 115091 diff --git a/marked/Y/T-REC-Y.1453-200603-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg b/marked/Y/T-REC-Y.1453-200603-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..b455502d3528516a799b3f62a2d22b8949b9bf42 --- /dev/null +++ b/marked/Y/T-REC-Y.1453-200603-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:0027b257b0ab17de5ae1d0ad325fc90edc2ab93e33adc2d22cce3caa92f586ed +size 6771 diff --git a/marked/Y/T-REC-Y.1453-200603-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg b/marked/Y/T-REC-Y.1453-200603-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..772c6360e37a1d94423e78b11a2d7e3800bdb795 --- /dev/null +++ b/marked/Y/T-REC-Y.1453-200603-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:f70758e5ff8150159e8457b2256ab1285ae8fb524a9d206625e672b65c23261e +size 49229 diff --git a/marked/Y/T-REC-Y.1453-200603-I_PDF-E/db7cb51aac8519daab50e2171cecae82_img.jpg b/marked/Y/T-REC-Y.1453-200603-I_PDF-E/db7cb51aac8519daab50e2171cecae82_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..5d044c1befaff1f87d82a8f362b06138272b6b37 --- /dev/null +++ b/marked/Y/T-REC-Y.1453-200603-I_PDF-E/db7cb51aac8519daab50e2171cecae82_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:bc4e24ff4ae1aec99ac376c74842d3ad793cfffec63717258fcfd6a4e5a4ebe5 +size 32207 diff --git a/marked/Y/T-REC-Y.1453-200603-I_PDF-E/raw.md b/marked/Y/T-REC-Y.1453-200603-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..74444a6e017a53115faa17a87a4d73fc80e41020 --- /dev/null +++ b/marked/Y/T-REC-Y.1453-200603-I_PDF-E/raw.md @@ -0,0 +1,1077 @@ + + +I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +## Y.1453 + +(03/2006) + +SERIES Y: GLOBAL INFORMATION +INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS +AND NEXT-GENERATION NETWORKS + +Internet protocol aspects – Interworking + +# --- **TDM-IP interworking – User plane interworking** + +ITU-T Recommendation Y.1453 + +![ITU logo](84a1d09fb489061482111515543b60dc_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with a red lightning bolt striking it, and the text "ITU" in blue, with "International Telecommunication Union" in smaller blue text below it. + +ITU logo + +## ITU-T Y-SERIES RECOMMENDATIONS **GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT- GENERATION NETWORKS** + +## GLOBAL INFORMATION INFRASTRUCTURE + +| | | +|-------------------------------------------|-------------| +| General | Y.100–Y.199 | +| Services, applications and middleware | Y.200–Y.299 | +| Network aspects | Y.300–Y.399 | +| Interfaces and protocols | Y.400–Y.499 | +| Numbering, addressing and naming | Y.500–Y.599 | +| Operation, administration and maintenance | Y.600–Y.699 | +| Security | Y.700–Y.799 | +| Performances | Y.800–Y.899 | + +## INTERNET PROTOCOL ASPECTS + +| | | +|--------------------------------------------------------------------|----------------------| +| General | Y.1000–Y.1099 | +| Services and applications | Y.1100–Y.1199 | +| Architecture, access, network capabilities and resource management | Y.1200–Y.1299 | +| Transport | Y.1300–Y.1399 | +| Interworking | Y.1400–Y.1499 | +| Quality of service and network performance | Y.1500–Y.1599 | +| Signalling | Y.1600–Y.1699 | +| Operation, administration and maintenance | Y.1700–Y.1799 | +| Charging | Y.1800–Y.1899 | + +## NEXT GENERATION NETWORKS + +| | | +|-------------------------------------------------------------------|---------------| +| Frameworks and functional architecture models | Y.2000–Y.2099 | +| Quality of Service and performance | Y.2100–Y.2199 | +| Service aspects: Service capabilities and service architecture | Y.2200–Y.2249 | +| Service aspects: Interoperability of services and networks in NGN | Y.2250–Y.2299 | +| Numbering, naming and addressing | Y.2300–Y.2399 | +| Network management | Y.2400–Y.2499 | +| Network control architectures and protocols | Y.2500–Y.2599 | +| Security | Y.2700–Y.2799 | +| Generalized mobility | Y.2800–Y.2899 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +## **ITU-T Recommendation Y.1453** + +# **TDM-IP interworking – User plane interworking** + +## **Summary** + +This Recommendation addresses required functions for network interworking between TDM networks up to DS3 or E3 rates and IP networks, in order to transport TDM traffic over IP networks. This Recommendation addresses user plane interworking mechanisms, connection multiplexing and procedures. These interworking mechanisms must ensure that TDM timing, signalling, voice quality, and alarm integrity be maintained. Details of the interworking model and required interworking functions are described. This Recommendation may not be suitable for use by Recognized Operating Agencies due to possible degradation of network synchronization performance as compared with native TDM transport. + +## **Source** + +ITU-T Recommendation Y.1453 was approved on 29 March 2006 by ITU-T Study Group 13 (2005-2008) under the ITU-T Recommendation A.8 procedure. + +## **Keywords** + +Interworking, IP, network interworking, TDM, UDP, user plane. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g. interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +### INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database. + +© ITU 2006 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## CONTENTS + +| | | Page | +|----|-------------------------------------------------------------------------------|-------------| +| 1 | Scope ..... | 1 | +| 2 | References..... | 1 | +| 3 | Definitions ..... | 3 | +| 4 | Abbreviations and acronyms ..... | 3 | +| 5 | Conventions ..... | 4 | +| 6 | TDM-IP interworking..... | 5 | +| 7 | General requirements..... | 6 | +| | 7.1 User plane requirements ..... | 6 | +| | 7.2 Management plane aspects ..... | 7 | +| | 7.3 Fault management aspects ..... | 8 | +| | 7.4 Traffic management aspects ..... | 9 | +| | 7.5 Connection admission control for the IWF ..... | 9 | +| 8 | Functional group considerations for TDM-IP network interworking..... | 10 | +| | 8.1 IP..... | 10 | +| | 8.2 UDP ..... | 10 | +| | 8.3 Common interworking indicators..... | 10 | +| | 8.4 Optional timing information..... | 12 | +| | 8.5 TDM payload..... | 12 | +| | 8.6 Summary of encapsulation format..... | 12 | +| 9 | Payload formats ..... | 16 | +| | 9.1 Structure-agnostic transport..... | 16 | +| | 9.2 Structure-aware transport ..... | 17 | +| 10 | Timing aspects ..... | 20 | +| 11 | Packet loss aspects..... | 20 | +| 12 | Support of CAS and CCS ..... | 20 | +| | 12.1 Support of CAS ..... | 20 | +| | 12.2 Support of CCS..... | 20 | +| 13 | Security considerations..... | 21 | +| | Appendix I – Optional processing of HDLC-based CCS signals ..... | 21 | +| | Appendix II – IP network performance metrics..... | 21 | +| | II.1 Errors in the IP network that impact TDM service ..... | 21 | +| | II.2 Relationship to TDM service impairment metrics ..... | 22 | +| | II.3 Availability requirements ..... | 23 | +| | II.4 Voice quality requirements..... | 23 | +| | Appendix III – Suggested payload sizes for structure-agnostic transport ..... | 24 | +| | Appendix IV – Suggested number of AAL1 SAR PDUs per packet..... | 24 | + +## **Introduction** + +There is a need to define network interworking wherein traffic from conventional synchronous or plesiochronous networks (hereafter denoted TDM networks) is transported over IP networks. Such interworking must ensure that TDM timing, signalling, voice quality, and alarm integrity be maintained. + +## ITU-T Recommendation Y.1453 + +# TDM-IP interworking – User plane interworking + +## 1 Scope + +This Recommendation addresses required functions for network interworking between TDM networks up to and including DS3/E3 rates and IP networks, in order to transport TDM traffic over IP networks. Transport of higher rate TDM services (such as SDH) over IP networks is beyond the scope of this Recommendation. This Recommendation addresses user plane interworking mechanisms, connection multiplexing and related procedures. These interworking mechanisms must ensure that TDM timing, signalling, telephony voice quality, and alarm integrity be maintained. Details of the interworking model and required interworking functions are described. This Recommendation may not be suitable for use by recognized operating agencies (ROAs) [1] due to possible degradation of network synchronization performance as compared with native TDM transport. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- [1] ITU-T Recommendation F.110 (1996), *Operational provisions for the maritime mobile service.* +- [2] ITU-T Recommendation Y.1411 (2003), *ATM-MPLS network interworking – Cell mode user plane interworking.* +- [3] ITU-T Recommendation Y.1413 (2004), *TDM-MPLS network interworking – User plane interworking.* +- [4] ITU-T Recommendation G.809 (2003), *Functional architecture of connectionless layer networks.* +- [5] ITU-T Recommendation G.702 (1988), *Digital hierarchy bit rates.* +- [6] ITU-T Recommendation G.705 (2000), *Characteristics of plesiochronous digital hierarchy (PDH) equipment functional blocks.* +- [7] ITU-T Recommendation G.114 (2003), *One-way transmission time.* +- [8] ITU-T Recommendation G.826 (2002), *End-to-end error performance parameters and objectives for international, constant bit-rate digital paths and connections.* +- [9] ITU-T Recommendation G.823 (2000), *The control of jitter and wander within digital networks which are based on the 2048 kbit/s hierarchy.* +- [10] ITU-T Recommendation G.824 (2000), *The control of jitter and wander within digital networks which are based on the 1544 kbit/s hierarchy.* +- [11] IETF RFC 791 (1981), *Internet Protocol – DARPA Internet Program – Protocol Specification.* +- [12] IETF RFC 2460 (1998), *Internet Protocol, Version 6 (IPv6) Specification.* + +- [13] IETF RFC 768 (1980), *User Datagram Protocol*. +- [14] ITU-T Recommendation G.703 (2001), *Physical/electrical characteristics of hierarchical digital interfaces*. +- [15] ITU-T Recommendation V.36 (1988), *Modems for synchronous data transmission using 60-180 kHz group band circuits*. +- [16] ITU-T Recommendation V.37 (1988), *Synchronous data transmission at a data signalling rate higher than 72 kbit/s using 60-108 kHz group band circuits*. +- [17] ITU-T Recommendation I.231.1 (1988), *Circuit-mode bearer service categories – Circuit-mode 64 kbit/s unrestricted, 8 kHz structured bearer service*. +- [18] ANSI T1.107 (2002), *Digital Hierarchy – Formats Specifications*. +- [19] ITU-T Recommendation G.751 (1988), *Digital multiplex equipments operating at the third order bit rate of 34 368 kbit/s and the fourth order bit rate of 139 264 kbit/s and using positive justification*. +- [20] ITU-T Recommendation G.704 (1998), *Synchronous frame structures used at 1544, 6312, 2048, 8448 and 44 736 kbit/s hierarchical levels*. +- [21] ITU-T Recommendation Q.700 (1993), *Introduction to CCITT Signalling System No. 7*. +- [22] ITU-T Recommendation Q.931 (1998), *ISDN user-network interface layer 3 specification for basic call control*. +- [23] ITU-T Recommendation I.363.1 (1996), *B-ISDN ATM Adaptation Layer specification: Type 1 AAL*. +- [24] IETF RFC 3550 (2003), *RTP: A Transport Protocol for Real-Time Applications*. +- [25] ITU-T Recommendation Y.1540 (2002), *Internet protocol data communication service – IP packet transfer and availability performance parameters*. +- [26] IETF RFC 2474 (1998), *Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Headers*. +- [27] IETF RFC 3246 (2002), *An Expedited Forwarding PHB (Per-Hop Behavior)*. +- [28] IETF RFC 2210 (1997), *The Use of RSVP with IETF Integrated Services*. +- [29] IETF RFC 2212 (1997), *Specification of Guaranteed Quality of Service*. +- [30] ATM Forum af-vtoa-0078.000 (1997), *Circuit Emulation Service 2.0*. +- [31] ITU-T Recommendation G.802 (1988), *Interworking between networks based on different digital hierarchies and speech encoding laws*. +- [32] ITU-T Recommendation Q.921 (1997), *ISDN user network interface – Data link layer specification*. +- [33] ITU-T Recommendation G.827 (2003), *Availability performance parameters and objectives for end-to-end international constant bit-rate digital paths*. +- [34] ITU-T Recommendation G.1020 (2003), *Performance parameter definitions for quality of speech and other voiceband applications utilizing IP networks*. +- [35] ITU-T Recommendation P.800 (1996), *Methods for subjective determination of transmission quality*. +- [36] ITU-T Recommendation P.862 (2001), *Perceptual evaluation of speech quality (PESQ): An objective method for end-to-end speech quality assessment of narrow-band telephone networks and speech codecs*. + +- [37] ITU-T Recommendation I.231.5 (1988), *Circuit-mode bearer service categories: Circuit-mode $2 \times 64$ kbit/s unrestricted, 8 kHz structured bearer service.* +- [38] ITU-T Recommendation I.231.10 (1992), *Circuit-mode bearer service categories: Circuit-mode multiple-rate unrestricted 8 kHz structured bearer service.* +- [39] ITU-T Recommendation I.231.6 (1996), *Circuit-mode bearer service categories: Circuit-mode 384 kbit/s unrestricted, 8 kHz structured bearer service.* + +## 3 Definitions + +This Recommendation uses or defines the following terms: + +**3.1 interworking:** See ITU-T Rec. Y.1411 [2]. + +**3.2 interworking flow:** A pair of G.809 flows [4] capable of simultaneously transferring information in opposite directions over an IP network for the purpose of transporting TDM traffic. + +**3.3 interworking function (IWF):** See ITU-T Rec. Y.1411. + +**3.4 ingress IWF:** The point where the continuous TDM stream is segmented and encapsulated into IP packets (TDM-to-IP direction). + +**3.5 egress IWF:** The point where TDM segments are de-encapsulated from IP packets and reassembled into a continuous TDM stream (IP-to-TDM direction). + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|----------|----------------------------------------| +| AAL | ATM Adaptation Layer | +| AIS | Alarm Indication Signal | +| AP | Access Point | +| ATM | Asynchronous Transfer Mode | +| CAS | Channel Associated Signalling | +| CCS | Common Channel Signalling | +| CES | Circuit Emulation Service | +| CP | Connection Point | +| CSI | Convergence Sublayer Indication | +| CSRC | Contributing Source | +| dAIS | AIS defect | +| Diffserv | Differentiated Services | +| dLOA | Loss of Alignment defect | +| dLOS | Loss of Signal defect | +| DSn | Digital Signal level n | +| EF PHB | Expedited Forwarding Per Hop Behaviour | +| En | Electrical Interface Signal, level n | +| FAS | Frame Alignment Signal | +| FCS | Frame Check Sequence | + +| | | +|---------|-------------------------------------------| +| GS | Guaranteed Service | +| HDLC | High level Data Link Control | +| Intserv | Integrated Services | +| IP | Internet Protocol | +| ISDN | Integrated Services Digital Network | +| IWF | InterWorking Function | +| LOF | Loss of Frame Synchronization | +| LOS | Loss of Signal | +| MPLS | Multi-Protocol Label Switch | +| MTU | Maximum Transport Unit | +| OAM | Operation, Administration and Maintenance | +| PDU | Protocol Data Unit | +| PDV | Packet Delay Variation | +| PLC | Packet Loss Concealment | +| PM | Performance Monitoring | +| PRI | Primary Rate Interface | +| PSTN | Public Switched Telephone Network | +| PT | Payload Type | +| QoS | Quality of Service | +| ROA | Recognized Operating Agency | +| RDI | Remote Defect Indication | +| RFC | Request for Comments | +| RTP | Real Time Protocol | +| SAR | Segmentation And Reassembly | +| SRTS | Synchronous Residual Time Stamp | +| SSRC | Synchronization Source | +| TDM | Time Division Multiplex | +| TFP | Termination Flow Point | +| UDP | User Datagram Protocol | + +## 5 Conventions + +This Recommendation uses traditional terminology for digital signals at the various levels of the G.702 [5] rate hierarchy. In particular, the first level digital signal of rate 2048 kbit/s (P12 in G.705 [6] terminology) is designated E1, and the third level signal of rate 34 368 kbit/s derived from it (P31), E3. Similarly, the first level signal of rate 1544 kbit/s (P11) is designated DS1, its second level derivative of rate 6312 kbit/s (P21), DS2, and its third level derivative at rate 44 736 kbit/s (P32), DS3. DS0 has the signal rate of 64 kbit/s. + +## 6 TDM-IP interworking + +This Recommendation defines interworking with TDM services up to and including DS3 or E3 rates. Transport of higher rate TDM services (such as SDH) over IP networks is beyond the scope of this Recommendation. + +TDM services are conventionally transported over networks operating in circuit-switched mode. + +A TDM client requires that its server layer constrains accuracy, ordering, and temporal impairments within defined bounds. For a connectionless server layer, the severity of these impairments may increase non-linearly with server layer loading. + +As the server layer loading may not be known in advance, and may vary over time, the layering of a TDM client over an IP server presents a significant challenge for equipment manufacturers and service providers to conform to ITU-T Recommendations relating to TDM performance. In particular, due to packet loss, delay and delay variation, the end-to-end delay [7], error [8], timing [9] and [10] performance will in general be degraded as compared with those experienced over a native TDM infrastructure. IP network performance is discussed in Appendix II. + +Therefore, users of an implementation of this Recommendation should be aware that it may not be possible to predict or guarantee performance. + +Figure 6-1 provides a general network architecture for TDM-IP network interworking where TDM networks are interconnected through an IP network [11] and [12]. Note that the path through the IP network will change over time as a result of IP routing protocols. + +For the TDM-to-IP direction, the continuous TDM stream is segmented and encapsulated into UDP/IP [13] packets by the interworking function (IWF). For the IP-to-TDM direction, the TDM segments are extracted from the UDP/IP packets and the continuous TDM stream is reassembled. + +Figure 6-2 depicts the network functional architecture of TDM-IP interworking using the diagrammatic techniques of ITU-T Rec. G.809 [4]. Examples for specific scenarios are given in Appendix III/Y.1413 [3]. + +Figure 6-3 shows the network reference model and protocol layers for TDM-IP user plane interworking. + +![Figure 6-1/Y.1453 – Reference architecture for TDM-IP network interworking. The diagram shows a network architecture where two TDM networks are interconnected via an IP network. On the left, 'End System 1' is connected to a 'TDM' network cloud. This cloud connects to an 'IWF' (Interworking Function) block, which is split into 'TDM' and 'IP' sections. The 'IP' section connects to an 'IP network' cloud containing several routers (circles) and an 'IP interworking tunnel' (thick line). The 'IP network' cloud connects to another 'IWF' block, split into 'IP' and 'TDM' sections. The 'TDM' section connects to a second 'TDM' network cloud, which is connected to 'End System 2'. Below the diagram, a legend indicates that a circle represents a 'Router' and a thick line represents an 'IP interworking tunnel'. The bottom right corner is labeled 'Y.1453_F6-1'.](18442e4e239480f0c3c95b547aa8fde2_img.jpg) + +Y.1453\_F6-1 + +Figure 6-1/Y.1453 – Reference architecture for TDM-IP network interworking. The diagram shows a network architecture where two TDM networks are interconnected via an IP network. On the left, 'End System 1' is connected to a 'TDM' network cloud. This cloud connects to an 'IWF' (Interworking Function) block, which is split into 'TDM' and 'IP' sections. The 'IP' section connects to an 'IP network' cloud containing several routers (circles) and an 'IP interworking tunnel' (thick line). The 'IP network' cloud connects to another 'IWF' block, split into 'IP' and 'TDM' sections. The 'TDM' section connects to a second 'TDM' network cloud, which is connected to 'End System 2'. Below the diagram, a legend indicates that a circle represents a 'Router' and a thick line represents an 'IP interworking tunnel'. The bottom right corner is labeled 'Y.1453\_F6-1'. + +**Figure 6-1/Y.1453 – Reference architecture for TDM-IP network interworking** + +![Figure 6-2/Y.1453: Functional architecture of TDM-IP network interworking. The diagram shows a TDM network on the left and right, each containing a TDM CP (Connection Point) and an IP/TDM interface. These interfaces connect to an IP network in the center. The IP network contains an IP AP (Access Point) and two IP TFP (Termination Flow Point) blocks. The TDM network is labeled 'TDM network' and the IP network is labeled 'IP network'. Below the diagram, the labels 'CP Connection Point', 'AP Access Point', and 'TFP Termination Flow Point' are provided. The reference 'Y.1453_F6-2' is at the bottom right.](d4af765160d04ecef538e5066006dc77_img.jpg) + +Figure 6-2/Y.1453: Functional architecture of TDM-IP network interworking. The diagram shows a TDM network on the left and right, each containing a TDM CP (Connection Point) and an IP/TDM interface. These interfaces connect to an IP network in the center. The IP network contains an IP AP (Access Point) and two IP TFP (Termination Flow Point) blocks. The TDM network is labeled 'TDM network' and the IP network is labeled 'IP network'. Below the diagram, the labels 'CP Connection Point', 'AP Access Point', and 'TFP Termination Flow Point' are provided. The reference 'Y.1453\_F6-2' is at the bottom right. + +**Figure 6-2/Y.1453 – Functional architecture of TDM-IP network interworking depicted according to the diagrammatic conventions of G.809** + +![Figure 6-3/Y.1453: Network reference model and protocol layers for TDM-IP user plane interworking. The top part shows a high-level view: a TDM circuit connected to an IWF (Interworking Function) block, which connects to an IP interworking tunnel, which then connects to another IWF block and finally to another TDM circuit. The bottom part shows a detailed protocol stack. On the left, the stack has 'Upper layers', 'TDM', and 'Physical' layers. The IWF blocks show a split between 'TDM' and 'IP' layers, with a 'Link layer' below. The IP interworking tunnel shows 'IP' and 'Link layer' blocks. The right side is a mirror image of the left. The reference 'Y.1453_F6-3' is at the bottom right.](042733dc5e8e7f5f30b60adba3266cde_img.jpg) + +Figure 6-3/Y.1453: Network reference model and protocol layers for TDM-IP user plane interworking. The top part shows a high-level view: a TDM circuit connected to an IWF (Interworking Function) block, which connects to an IP interworking tunnel, which then connects to another IWF block and finally to another TDM circuit. The bottom part shows a detailed protocol stack. On the left, the stack has 'Upper layers', 'TDM', and 'Physical' layers. The IWF blocks show a split between 'TDM' and 'IP' layers, with a 'Link layer' below. The IP interworking tunnel shows 'IP' and 'Link layer' blocks. The right side is a mirror image of the left. The reference 'Y.1453\_F6-3' is at the bottom right. + +**Figure 6-3/Y.1453 – Network reference model and protocol layers for TDM-IP user plane interworking** + +## 7 General requirements + +### 7.1 User plane requirements + +For transfer of TDM streams over IP networks, the following capabilities are required: + +- a) The ability to transport multiple TDM streams between two IWFs. +- b) Support for bidirectional flows with symmetric bandwidth and binding to the duplex TDM. +- c) The ability to transport the following unstructured TDM types: + - 1) DS1 at 1544 kbit/s as defined in ITU-T Rec. G.703 [14]; + - 2) E1 at 2048 kbit/s as defined in ITU-T Rec. G.703; + - 3) DS2 at rate 6312 kbit/s as defined in ITU-T Rec. G.703; + - 4) Synchronous serial data as defined in ITU-T Recs V.36 [15] and V.37 [16]; + +- 5) $N \times 64$ k (i.e., for $N = 1$ as defined in ITU-T Rec. I.231.1 [17], for $N = 2$ as defined in ITU-T Rec. I.231.5 [37], for $N = 3$ as defined in ITU-T Rec. I.231.10 [38] and for $N = 6$ as defined in ITU-T Rec. I.231.6 [39]); + - 6) DS3 at 44 736 kbit/s as defined in ANSI T1.107 [18]; + - 7) E3 at 34 368 kbit/s as defined in ITU-T Rec. G.751 [19]. +- d) The ability to transport the following structured TDM types: +- 1) DS1 as defined in ITU-T Rec. G.704 [20]; + - 2) Fractional DS1 carrying $N$ timeslots with $N$ from 1 to 23 as defined in ANSI T1.107; + - 3) E1 as defined in ITU-T Rec. G.704; + - 4) Fractional E1 carrying $N$ timeslots with $N$ from 1 to 30 as defined in ITU-T Rec. G.704; + - 5) Multiple synchronous DS0s; + - 6) DS2 defined in ITU-T Rec. G.704. +- e) The ability to transport the structured TDM types of items d 1, 2, 3, 4, 6 with Channel Associated Signalling (CAS), as defined in ANSI T1.107 and ITU-T Rec. G.704. +- f) The ability to transport trunk- or facility-associated Common Channel Signalling (CCS), e.g., as defined in ITU-T Recs Q.700 [21] and Q.931 [22]. +- g) The ability of the egress IWF to derive timing from an external clock signal, or to exploit a common clock source, or to recover TDM timing by adaptive means. +- h) Conformance of timing recovery to the jitter and wander specifications of a [9] or [10] traffic interface. +- i) The ability to interwork with existing Circuit Emulation Services (CES) carried in MPLS [3] or ATM networks [23]. +- j) The ability to reliably detect packet loss and misordering. +- k) The ability to inject AIS or filler data to compensate for lost packets. +- l) The ability to operate over arbitrary IP networks, but to exploit QoS features of IP networks if they are present. +- m) The ability of the IWFs to maintain TDM frame synchronization (and multi-frame synchronization when applicable) for structure-aware transport. +- n) The ability to set payload length to ensure that packet size does not exceed the path maximum transport unit (MTU). + +### 7.2 Management plane aspects + +For transfer of TDM services over IP networks, the following capabilities shall be provisioned: + +- a) UDP source and destination port values for both directions. +- b) The type of TDM traffic as per 7.1 c) and d). +- c) For serial data (7.1 c) 4): the bit rate. +- d) For $N \times 64$ k (7.1 c) 4): the value of $N$ . +- e) For fractional E1 or DS1 (7.1 d) 2 or 4): the value of $N$ . +- f) The payload format (see clause 9). +- g) For structure-agnostic transport: the number of payload octets per IP packet. +- h) For unstructured DS1: if DS1-octet aligned mode is used. +- i) For structure-locked encapsulation: the number of frames per IP packet. + +- j) For structure-indicated encapsulation: + - 1) the number of 48-octet PDUs per packet; + - 2) AAL 1 mode: unstructured, structured or structured with CAS. +- k) Indication of whether RTP [24] is used. +- l) If RTP is used: + - 1) whether the timestamp is determined from a common clock; + - 2) the common clock frequency divided by 8 kHz; + - 3) the payload type (PT); + - 4) the SSRC value. + +### **7.3 Fault management aspects** + +The interworking function shall support transfer of defect information between IP and TDM networks, as depicted in Figure 7-1. In particular, local TDM defects [6], such as loss of signal or loss of synchronization, shall be signalled from ingress to egress IWF; and IP anomalies [25], such as packet misordering and loss, shall be detected by the egress IWF. + +The interworking function shall transfer TDM defect indications through the IP network by setting appropriate flags in the common interworking indicators. Definition of TDM defect states and criteria for entering and exiting those states are defined in ITU-T Rec. G.705 [6]. The encoding need not be one-to-one, i.e., a single indicator of invalid TDM data may be used to indicate multiple TDM defects or indications (e.g., dLOS, dLOA or dAIS). In addition, if applicable, an appropriate alarm shall be sent to the management layer. + +The egress IWF detects IP anomalies by monitoring the timely arrival of packets and by the sequence number in the common interworking indicators. Regardless of anomalies, the egress IWF shall ensure synchronization integrity of its local TDM interface. The egress IWF shall maintain statistical record of anomalies, and when the density of anomalies is such as to comprise a defect, it shall inform the ingress IWF of the defect and shall send the appropriate alarm to the management layer. + +The ability to distinguish between faults in the IP network and those in the remote TDM network shall be provided. + +![Figure 7-1/Y.1453 – Functional representation of TDM-IP fault management. The diagram shows a TDM network connected to an IP network via two IWFs. Below the main diagram are two detailed views of the IWFs. The left IWF shows LOS, LOF, AIS, RDI on the left and L, R, M on the right. The right IWF shows L, R, M on the left and LOS, LOF, AIS, RDI on the right. A management bar at the bottom indicates TDM management on the ends and IP management in the middle.](33ed1f9b27c7c21c797aa928b0f06851_img.jpg) + +Y.1453\_F7-1 + +Figure 7-1/Y.1453 – Functional representation of TDM-IP fault management. The diagram shows a TDM network connected to an IP network via two IWFs. Below the main diagram are two detailed views of the IWFs. The left IWF shows LOS, LOF, AIS, RDI on the left and L, R, M on the right. The right IWF shows L, R, M on the left and LOS, LOF, AIS, RDI on the right. A management bar at the bottom indicates TDM management on the ends and IP management in the middle. + +AIS Alarm Indication Signal + LOF Loss of Frame synchronization (detected only) + LOS Loss of Signal defect (detected only) + RDI Remote Defect Indication + +**Figure 7-1/Y.1453 – Functional representation of TDM-IP fault management** + +### 7.4 Traffic management aspects + +The IP flow shall be capable of providing the required QoS for all TDM connections, and must be capable of meeting the aggregate bandwidth requirements of all TDM connections transported. + +If the IP network is Diffserv enabled according to RFC 2474 [26], then expedited forwarding per hop behaviour (EF PHB) per RFC 3246 [27] with appropriate traffic conditioning shall be used in order to provide a low latency and minimal jitter service. It is suggested that the IP network be somewhat over provisioned. + +If the IP network is Intserv enabled according to RFC 2210 [28], then guaranteed service (GS) per RFC 2212 [29] with a bandwidth reservation greater than that of the aggregate TDM traffic shall be used in order to guarantee sufficient bandwidth and bounded delay. + +The expected delay introduced by the network should be measured prior to traffic flow, to estimate latency. This measurement may only be meaningful when the service provider manages the IP network load. + +### 7.5 Connection admission control for the IWF + +When bandwidth guarantees can be provided, then the IWF should provide connection admission control. The admission decision shall be based on the total bandwidth allocation of the IP network, the bandwidth presently being consumed by interworking flows and other clients of the IP network, and the bandwidth requested. When sufficient bandwidth is available, the request may be granted. When bandwidth is insufficient, the TDM connection request must be denied. + +## 8 Functional group considerations for TDM-IP network interworking + +Figure 8-1 provides an illustration of functional grouping for TDM-IP network interworking. + +| | +|--------------------------------| +| IP | +| UDP | +| Optional timing information | +| Common interworking indicators | +| TDM Payload | + +NOTE – Bit 8 is the most significant bit. + +**Figure 8-1/Y.1453 – TDM-IP interworking functional groups** + +### 8.1 IP + +This field is the standard IPv4 [11] or IPv6 [12] header. + +### 8.2 UDP + +Since it may be required to transport multiple emulated TDM streams between two IP addresses, a method of labelling TDM-IP flows is required. Only manual provisioning of this label is considered in this Recommendation. The label may be placed in the UDP source port field, or the UDP destination port field per RFC 768 [13]. When the source port field is used, the destination port field may contain an identifier indicating that the packet contains TDM data. + +### 8.3 Common interworking indicators + +The functions in the Common interworking indicators are related to the interworking flow and are independent of any specific service or encapsulation. In general the Common interworking indicators is comprised of a control field, a fragmentation field (FRAG), a length field, and a sequence number field, as depicted in Figure 8-2. + +| | | | | | | | | +|----------------------------|---|---|--------|---|---|---|---| +| Bit | | | | | | | | +| 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | +| Control | | | | | | | | +| FRAG | | | Length | | | | | +| Sequence number (2 octets) | | | | | | | | + +NOTE – Bit 8 is the most significant bit. + +**Figure 8-2/Y.1453 – Common interworking indicators** + +#### 8.3.1 Control field + +The format of the control field is depicted in Figure 8-3. + +| | | | | | | | | +|----------|---|---|---|---|---|---|---| +| Bit | | | | | | | | +| 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | +| Reserved | | | | L | R | M | | + +NOTE – Bit 8 is the most significant bit. + +**Figure 8-3/Y.1453 – Control field** + +The reserved field shall be set to zero. + +The L, R and M fields provide a means of transfer of TDM defect indications between IWFs. Their use should be in accordance with principles of the appropriate G series of ITU-T Recommendations with regard to operation, administration and maintenance (OAM). + +**L** Local TDM failure: The L bit being set (i.e., L = 1) indicates that the ingress IWF has detected or has been informed of a TDM defect impacting the TDM data. When the L bit is set the contents of the packet may not be meaningful, and the payload may be suppressed in order to conserve bandwidth. Once set, if the TDM fault is rectified then the L bit shall be cleared. + +**R** Remote Receive failure: The R bit being set (i.e., R = 1) indicates that the source of the packet is not receiving packets from the IP network. Thus the setting of the R bit indicates failure of the opposite direction. This indication can be used to signal IP network congestion or other network related faults. The R bit shall be set after a preconfigured number of consecutive packets are not received, and shall be cleared once packets are once again received. + +**M** Defect Modifier: Use of the M field is optional, and when used it supplements the meaning of the L bit. + +When L is cleared (indicating valid TDM data), the M field is used as follows: + +##### **M** + +- 0 0 Indicates no local defect modification. +- 0 1 Reserved. +- 1 0 Reports receipt of RDI at the TDM input to the ingress IWF. +- 1 1 Reserved. + +When L bit is set (indicating invalid TDM data), the M field is used as follows: + +##### **M** + +- 0 0 Indicates a TDM defect that should trigger AIS generation at the far end. +- 0 1 Indicates idle TDM data, which should not cause any alarm to be raised. If the payload has been suppressed, then appropriate idle code should be generated at egress. +- 1 0 Indicates corrupted but potentially recoverable TDM data. The use of this indication is for further study. +- 1 1 Reserved. + +#### **8.3.2 Fragmentation field** + +This field is used for fragmenting multi-frame structures into multiple packets as described in 9.2.1. The field is used as follows: + +##### **FRAG** + +- 0 0 Indicates that the entire (unfragmented) multi-frame structure is carried in a single packet. +- 0 1 Indicates the packet carrying the first fragment. +- 1 0 Indicates the packet carrying the last fragment. +- 1 1 Indicates a packet carrying an intermediate fragment. + +#### **8.3.3 Length field** + +When an IP packet is transported over Ethernet, a minimum packet size of 64 octets is required. This may require padding to be applied to the interworking packet payload in order to reach this minimum packet size. The padding size can be determined from the length field so that the padding can be extracted at the egress. + +The Length field indicates the size of the IP packet payload in octets, and its value is the sum of: + +- a) size of the Common interworking indicators (4 octets); +- b) size of the optional timing information; and +- c) size of the payload, + +unless this sum equals or exceeds 64 octets, in which case the Length field shall be set to zero. + +#### **8.3.4 Sequence number field** + +The Sequence number field is a two-octet field that is used to detect lost packets and packet misordering. + +The sequence number space is a 16-bit, unsigned circular space, set and processed as defined below. + +##### **8.3.4.1 Setting the sequence numbers** + +The following procedures apply at the ingress IWF (TDM-to-IP direction): + +- The sequence number should be set to a random value for the first IP packet transmitted over the interworking flow. +- For each subsequent IP packet, the sequence number shall be incremented by 1, modulo $2^{16}$ . + +##### **8.3.4.2 Processing the sequence numbers** + +The purpose of the sequence number processing is to detect lost or misordered packets. The treatment of lost packets is discussed in clause 11. Misordered packets should be reordered, if possible. The mechanism for detecting packet loss is implementation specific. + +The following procedures apply at the egress IWF (IP-to-TDM direction): + +- The egress IWF maintains an expected sequence number. +- The first packet received from the IP network is always considered to be the expected packet, and the expected sequence number is equated to its sequence number. +- If the sequence number equals or is greater (in the cyclic sense) than the expected number, then the expected sequence number is set to the received number incremented by 1 modulo $2^{16}$ , otherwise the expected number is unchanged. + +### **8.4 Optional timing information** + +Optional timing information may be carried using the RTP header defined in RFC 3550 [24]. + +If used, the RTP header shall appear in each interworking packet immediately after the UDP/IP header and before the common interworking indicators field. + +### **8.5 TDM payload** + +The format of the TDM payload is detailed in clause 9. + +### **8.6 Summary of encapsulation format** + +This clause provides two encapsulation formats, one when an RTP header is absent (see Figure 8-4) and the other when an RTP header is present (see Figure 8-5). + +| Bit | | | | | | | | Octets | | | | | | | | | | +|-----------------------------|---|--------|-----------------|-----|---|---|---|--------|--|--|--|--|--|--|--|--|--| +| 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | | | | | | | | | | | +| IP version | | | | IHL | | | | 1 | | | | | | | | | | +| IP TOS | | | | | | | | 2 | | | | | | | | | | +| Total length | | | | | | | | 3-4 | | | | | | | | | | +| Identification | | | | | | | | 5-6 | | | | | | | | | | +| Flags | | | Fragment offset | | | | | 7 | | | | | | | | | | +| | | | | | | | | 8 | | | | | | | | | | +| Time to Live (TTL) | | | | | | | | 9 | | | | | | | | | | +| Protocol | | | | | | | | 10 | | | | | | | | | | +| IP header checksum | | | | | | | | 11-12 | | | | | | | | | | +| Source IP address | | | | | | | | 13-16 | | | | | | | | | | +| Destination IP address | | | | | | | | 17-20 | | | | | | | | | | +| Source UDP port number | | | | | | | | 21-22 | | | | | | | | | | +| Destination UDP port number | | | | | | | | 23-24 | | | | | | | | | | +| UDP Length | | | | | | | | 25-26 | | | | | | | | | | +| UDP checksum | | | | | | | | 27-28 | | | | | | | | | | +| Reserved | | | | L | R | M | | 29 | | | | | | | | | | +| FRAG | | Length | | | | | | 30 | | | | | | | | | | +| Sequence number | | | | | | | | 31-32 | | | | | | | | | | +| Adapted payload | | | | | | | | 33-n | | | | | | | | | | + +NOTE – Bit 8 is the most significant bit. + +**Figure 8-4/Y.1453 – Encapsulation format without the use of RTP** + +The first twenty octets are the IP header; octets 21 through 28 are the UDP header. Octets 29 through 32 are the common interworking indicators. + +Descriptions of the fields are as follows: + +#### **IP version, octet 1, bits 8 through 5** + +Indicates IP version number, e.g., for IPv4, IP Version = 4. + +#### **IHL, octet 1, bits 4 through 1** + +Indicates the length (in 32-bit words) of the IP header, e.g., IHL = 5. + +#### **IP TOS, octet 2** + +Indicates the IP type of service. + +#### **Total length, octets 3 and 4** + +Indicates the length (in octets) of header and IP payload. + +#### **Identification, octets 5 and 6** + +IP fragmentation identification field [11]. + +#### **Flags, octet 7, bits 8 through 6** + +Indicates IP control flags and shall be set to Flags = 010 to avoid fragmentation. + +#### **Fragment Offset, octet 7, bits 5 through 1 and octet 8** + +Indicates where in the datagram the fragment belongs and is not used. + +#### **Time to Live, octet 9** + +Indicate the IP TTL field. Datagrams with zero in this field are to be discarded. + +#### **Protocol, octet 10** + +Indicates protocol type and shall be set to 0x11 (i.e., hexadecimal 11) to signify UDP. + +#### **IP Header Checksum, octets 11 and 12** + +Indicates the checksum for the IP header. + +#### **Source IP Address, octets 13 through 16** + +Indicates the source IP address. + +#### **Destination IP Address, octets 17 through 20** + +Indicates the destination IP address. + +#### **Source Port Number, octets 21 and 22, and Destination Port Number, octets 23 and 24** + +Either of these fields may be used to uniquely identify the specific TDM stream being transported. The UDP flow shall be manually configured. + +When the source port is used to identify the TDM stream, the destination port number may be used to identify the UDP packet as conforming to this Recommendation. + +When used as a TDM stream identifier, the UDP port number shall be chosen from the range of dynamically allocated UDP ports numbers (49 152 through 65 535). + +The choice of whether the source port field or destination port field is used as TDM stream identifier is implementation dependent, but the choice shall be agreed upon by ingress and egress IWFs. + +#### **UDP Length, octets 25 and 26** + +Indicates the length in octets of UDP header and UDP payload. + +#### **UDP Checksum, octets 27 and 28** + +Indicates the checksum of UDP/IP header and payload. If not computed it must be set to zero. + +#### **Reserved, octet 29, bits 8 to 5** + +Indicates a reserved field which shall be set to zero. + +#### **L, R, and M octet 29, bits 4 through 1** + +See 8.3.1. + +#### **FRAG, octet 30, bits 8 and 7** + +See 8.3.2. + +#### **Length, octet 30, bits 6 through 1** + +See 8.3.3. + +#### **Sequence number, octets 31 and 32** + +See 8.3.4. + +When the RTP header appears, the packet format is as depicted in Figure 8-5. + +![](5b8a756d9a71c35f17db8bcb90b438a3_img.jpg) + +| Bit | | | | Octets | | | | | +|-----------------------------|----|--------|---|-----------------|---|---|---|-------| +| 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | | +| IP version | | | | IHL | | | | 1 | +| IP TOS | | | | | | | | 2 | +| Total length | | | | | | | | 3-4 | +| Identification | | | | | | | | 5-6 | +| Flags | | | | Fragment offset | | | | 7 | +| | | | | | | | | 8 | +| Time to Live (TTL) | | | | | | | | 9 | +| Protocol | | | | | | | | 10 | +| IP header checksum | | | | | | | | 11-12 | +| Source IP address | | | | | | | | 13-16 | +| Destination IP address | | | | | | | | 17-20 | +| Source UDP port number | | | | | | | | 21-22 | +| Destination UDP port number | | | | | | | | 23-24 | +| UDP Length | | | | | | | | 25-26 | +| UDP checksum | | | | | | | | 27-28 | +| RTV | | P | X | CC | | | | 29 | +| Mark | PT | | | | | | | 30 | +| RTP sequence number | | | | | | | | 31-32 | +| RTP timestamp | | | | | | | | 33-36 | +| SSRC identifier | | | | | | | | 37-40 | +| Reserved | | | | R | L | M | | 41 | +| FRAG | | Length | | | | | | 42 | +| Sequence number | | | | | | | | 43-44 | +| Adapted payload | | | | | | | | 45-n | + +NOTE – Bit 8 is the most significant bit. + +**Figure 8-5/Y.1453 – Encapsulation format with the use of RTP** + +Descriptions of fields not described above are as follows: + +The fields of RTP header shall be used as follows: + +- **RTV** (version) is always set to 2. +- **P** (padding), **X** (header extension), **CC** (CSRC count) and **Mark** (marker) are always set to 0. Accordingly, RTP header extensions, padding and contributing synchronization sources are never used. +- **PT** (payload type) is used as follows: + - a) A PT value shall be allocated from the range of dynamic values for each direction of the interworking flow. + - b) The ingress IWF shall set the PT field in the RTP header to the allocated value. +- The **RTP sequence number** shall be equal to the sequence number in the common interworking indicators. +- **RTP timestamps** are used for carrying timing information over the network: + - a) Their values are generated in accordance with the rules established in RFC 3550 [24]. + - b) The clock frequency used for generating timestamps should be an integer multiple of 8 kHz. Guidance for the proper selection of this clock frequency is given in Appendix V/Y.1413 [3]. + +- The SSRC (synchronization source) identifier field in the RTP header may be used for detection of misconnections. + +## 9 Payload formats + +Clause 9.1 specifies the payload format for structure-agnostic transport, while clause 9.2 defines two payload formats for structure-aware transport. Subclause 9.2.1 specifies the structure-locked encapsulation, and subclause 9.2.2 specifies structure-indicated encapsulation based on AAL type 1, as defined in ITU-T Rec. I.363.1 [23] and ATM Forum CES 2.0 [30]. + +### 9.1 Structure-agnostic transport + +Structure-agnostic transport completely disregards any TDM structure, in particular the structure imposed by standard TDM framing of ITU-T Rec. G.704 [20]. + +The payload format for structure-agnostic transport supports all the TDM services of clause 7.1, items c, d and e. + +For structure-agnostic transport arbitrary fixed length TDM segments are used, with no byte or frame alignment implied. The number of octets in the TDM segment: + +- shall be preconfigured; +- shall be the same for both directions; and +- shall remain unchanged for the lifespan of the connection for valid TDM data. + +Guidance for the proper selection of the number of octets per packet is given in Appendix III. + +When the L bit is set, TDM-IP packets may omit invalid TDM payloads in order to conserve bandwidth. + +Whenever a packet is lost, or received too late for playout, or is received with the L bit set, then the egress IWF shall generate the appropriate amount of AIS towards its TDM interface. + +NOTE – The use of AAL type 1 as described in 9.2.2 below may also be used for structure-agnostic transport. Examples where this may be beneficial are when interworking with ATM-based circuit emulation systems, or when SRTS-based clock recovery is used. + +#### 9.1.1 Octet-aligned DS1 payload format + +DS1 circuits may be delivered to the ingress IWF padded to an integer number of octets, as described in Annex B/G.802 [31]. In this format, the payload consists of an integer number of 25-octet sub-frames, each sub-frame consisting of 193 bits of TDM data and 7 bits of padding as shown in Figure 9-1 below: + +![Diagram of the Octet-aligned DS1 payload format showing a 25-octet sub-frame structure.](db7cb51aac8519daab50e2171cecae82_img.jpg) + +The diagram illustrates the structure of a 25-octet sub-frame. It is represented as a large rectangle divided into horizontal sections. The top section is labeled 'First octet of TDM data'. The second section is labeled 'Second octet of TDM data'. Below this, there are three vertical dots indicating intermediate octets. The next section is labeled 'Twenty-third octet of TDM data'. The following section is labeled 'Twenty-fourth octet of TDM data'. The bottom section is divided into two parts: the left part is labeled '\*\*\*' and the right part is labeled '7 Padding bits'. Above the rectangle, the word 'Bit' is centered, and the numbers 8, 7, 6, 5, 4, 3, 2, 1 are positioned above the corresponding octets, indicating bit numbering from most significant to least significant. + +Diagram of the Octet-aligned DS1 payload format showing a 25-octet sub-frame structure. + +\*\*\* Last bit of TDM data + +NOTE – Bit 8 is the most significant bit. + +**Figure 9-1/Y.1453 – Octet-aligned DS1 payload format** + +### 9.2 Structure-aware transport + +Structure-aware transport maintains correct operation of the remote TDM interface by regenerating frame alignment signal (FAS) at egress, and preserves integrity of the TDM structure by structure-locking or structure-indication. + +Whenever a packet is lost, or received too late for playout, or is received with the L bit set, then the egress IWF shall generate the appropriate amount of filler data in order to maintain TDM timing and FAS. While the insertion of arbitrary filler data may be sufficient to maintain the TDM timing, this may lead to reduced perceived quality of telephony voice channels contained in the TDM. Depending on the expected percentage of packet loss, packet loss concealment (PLC) mechanisms may need to be employed. + +The payload formats for structure-aware transport support all the TDM services of clause 7.1, items d and e. + +#### 9.2.1 Structure-locked encapsulation + +All packets shall carry the same amount of TDM data in both directions. Thus, the time required to fill a packet with TDM data is always the same. + +If the egress IWF substitutes filler data due to having received a packet with L bit set, it shall ensure that proper FAS bits [20] are sent to the TDM network. + +For services listed in 7.1, item d, the packet payload is comprised of an integer number of frames, and is aligned on the first octet of the first frame. If the packet payload is comprised of M frames, the packetization latency will be M times 125 microseconds (125 $\mu$ s). + +For services listed in 7.1, item e, the packet payload is comprised of an entire multi-frame. Alternatively, the multi-frame may be fragmented into an integer number of equal-sized fragments, where the first octet of each fragment is the first octet of a frame. Each fragment is placed into a separate packet and fragmentation is indicated by the FRAG field in the Common interworking indicators, as described in 8.3.2. The CAS signalling information shall be appended as a dedicated signalling substructure, as follows: + +- the four CAS bits belonging to each consecutive timeslot are placed in the signalling substructure as depicted in Figure 9-3; +- the CAS bits A, B, C, and D, as identified in Table 1/G.704 [20], are positioned from most significant to least significant bit of the nibble; +- if the number of timeslots is odd, a padding nibble shall be appended in order to maintain octet alignment; +- if the multi-frame structure is fragmented among several packets, the signalling substructure is always appended to the last fragment of the structure. + +The resulting payload formats are shown in Figures 9-2 and 9-3 below. + +| Frame | Bit | | | | | | | | +|-------|------------------------------|---|---|---|---|---|---|---| +| | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | +| 1 | Bits belonging to timeslot 1 | | | | | | | | +| | Bits belonging to timeslot 2 | | | | | | | | +| | ... | | | | | | | | +| | Bits belonging to timeslot N | | | | | | | | +| 2 | Bits belonging to timeslot 1 | | | | | | | | +| | Bits belonging to timeslot 2 | | | | | | | | +| | ... | | | | | | | | +| | Bits belonging to timeslot N | | | | | | | | +| ... | ... | | | | | | | | +| M | Bits belonging to timeslot 1 | | | | | | | | +| | Bits belonging to timeslot 2 | | | | | | | | +| | ... | | | | | | | | +| | Bits belonging to timeslot N | | | | | | | | + +NOTE 1 – Bit 8 is the most significant bit. + +NOTE 2 – The packet contains M TDM frames with N timeslots per frame. + +**Figure 9-2/Y.1453 – Payload format for structure-locked encapsulation without CAS (the IP packet does not carry a signalling substructure)** + +| Frame | Bit | | | | | | | | +|-------------------------|--------------------------------|---|---|---|--------------------------------|---|---|---| +| | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | +| 1 | Bits belonging to timeslot 1 | | | | | | | | +| | Bits belonging to timeslot 2 | | | | | | | | +| | ... | | | | | | | | +| | Bits belonging to timeslot N | | | | | | | | +| 2 | Bits belonging to timeslot 1 | | | | | | | | +| | Bits belonging to timeslot 2 | | | | | | | | +| | ... | | | | | | | | +| | Bits belonging to timeslot N | | | | | | | | +| ... | ... | | | | | | | | +| M | Bits belonging to timeslot 1 | | | | | | | | +| | Bits belonging to timeslot 2 | | | | | | | | +| | ... | | | | | | | | +| | Bits belonging to timeslot N | | | | | | | | +| Signalling substructure | Signalling bits for timeslot 1 | | | | Signalling bits for timeslot 2 | | | | +| | Signalling bits for timeslot 3 | | | | ... | | | | +| | Signalling bits for timeslot N | | | | Padding
(see Note 3) | | | | +| | | | | | | | | | + +NOTE 1 – Bit 8 is the most significant bit. + +NOTE 2 – The packet contains M TDM frames with N timeslots per frame, plus the signalling substructure. + +NOTE 3 – If N is odd, four bits of padding are added. + +**Figure 9-3/Y.1453 – Payload formats for structure-locked encapsulation with CAS (the IP packet carries the signalling substructure)** + +#### 9.2.2 Structure-indicated encapsulation + +For this encapsulation the TDM bit stream is adapted using AAL Type 1, as described in ITU-T Rec. I.363.1 [23] and ATM Forum CES 2.0 [30], to form 48-octet AAL Type 1 SAR PDUs, as described in 2.4.2/I.363.1. + +The packet payload consists of one or more PDUs, as depicted in Figures 9-4 and 9-5. The number of PDUs per packet: + +- shall be preconfigured; +- shall be the same for both directions; and +- shall remain unchanged for the lifespan of the connection. + +Guidance for the selection of the number of PDUs per packet is given in Appendix IV. + +![](26d664119ad25250780f554633444e54_img.jpg) + +| | | | | | | | | +|--------------------------------|---|---|---|---|---|---|---| +| 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | +| Common interworking indicators | | | | | | | | +| PDU payload (48 octets) | | | | | | | | + +NOTE – Bit 8 is the most significant bit. + +**Figure 9-4/Y.1453 – Structure-indicated encapsulation with a single PDU per packet** + +![](2734e7f9be3e1dc046f14be2e6c9a085_img.jpg) + +| | | | | | | | | +|--------------------------------|---|---|---|---|---|---|---| +| 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | +| Common interworking indicators | | | | | | | | +| PDU payload (48 octets) | | | | | | | | +| PDU payload (48 octets) | | | | | | | | +| PDU payload (48 octets) | | | | | | | | + +NOTE – Bit 8 is the most significant bit. + +**Figure 9-5/Y.1453 – Structure-indicated encapsulation with multiple PDUs per packet** + +AAL type 1 differentiates between unstructured and structured data transfer, which correspond to the structure-agnostic and structure-aware transport of this Recommendation. + +For structure-agnostic transport, AAL type 1 provides no inherent advantage as compared to the method of 9.1; however, there may be scenarios for which its use is desirable. For example, when it is necessary to interwork with an existing AAL type 1 ATM circuit emulation systems, or when clock recovery based on AAL 1-specific mechanisms is favoured. + +Each 48-octet SAR-PDU consists of a SAR-PDU header, and a SAR-PDU payload. The SAR-PDU header contains a convergence sublayer indication (CSI) [23] bit that signifies the appearance of a structure pointer for structured data transfer, and may be used for clock recovery (see clause 10). + +For unstructured AAL type 1, the 48 octets in each sub-frame contain a single octet SAR-PDU header, and 47 octets (376 bits) of TDM data. + +For structure-aware transport, ATM Forum CES 2.0 [30] defines two modes, structured and structured with CAS. Structured AAL type 1 carries octet-aligned TDM and maintains TDM frame synchronization by embedding a pointer to the beginning of the next frame in the SAR-PDU header. Structured AAL type 1 with CAS carries octet-aligned TDM and maintains TDM frame and multi-frame synchronization by embedding a pointer to the beginning of the next multi-frame; it furthermore contains a substructure including the CAS signalling bits (see 9.2.1). + +## **10 Timing aspects** + +TDM networks distribute timing information in order to maintain the required performance level. Since IP networks have no inherent timing distribution mechanism, other methods of timing distribution or recovery must be provided. Such methods are beyond the scope of this Recommendation. + +## **11 Packet loss aspects** + +Some degree of packet loss cannot be avoided in an IP network, hence some packet integrity mechanism shall be provided. Malformed packets and out of order packets may also be considered as lost. Retransmission is not a viable option for TDM-IP interworking, and so appropriate action shall be taken to compensate for packet loss. + +When loss of packets is detected, the IWF shall insert the required amount of AIS or filler data towards the End System in order to retain TDM timing. When CAS is employed, care should be taken by structure-aware mechanisms to maintain signalling state. + +Structure-agnostic transport cannot identify structure overhead, and so transports it transparently in the TDM segments. Hence, filler data will in general introduce an incorrect FAS. It may be possible to enhance FAS integrity by appropriately aligning the packet duration with the FAS period. However, the End System interface will still observe a corresponding amount of errored blocks [8]. + +For structure-aware transport structure overhead will be regenerated by the IWF. As a consequence, presence of packet loss in the IP network will be completely hidden from the End System TDM interface. + +For TDM carrying telephony channels, the insertion of filler data will lead to reduced perceived audio quality. Depending on the expected percentage of packet loss, packet loss concealment (PLC) mechanisms may need to be employed. PLC mechanisms are beyond the scope of this Recommendation. + +## **12 Support of CAS and CCS** + +CAS or CCS telephony signalling may be employed over TDM networks, and these signals must be reliably transported over the IP network for the End Systems to function properly. + +Handling of CAS and CCS shall be transparent, i.e., the IWF should not need detailed understanding of the End System signalling protocols in order to properly transport this signalling. + +### **12.1 Support of CAS** + +CAS is carried in the TDM frames as a sequence of bits that are uniquely associated with particular timeslots. + +Structure-agnostic transport of 9.1 cannot identify CAS bits, and so transports them transparently in the TDM segments. Hence, in the presence of packet loss, it is not possible to ensure integrity of the CAS bits, and structure-agnostic transport relies on the End Systems to be able to withstand a certain interval of error condition. + +The structure-locked method of 9.2.1 ensures CAS integrity by appending to the packet an explicit CAS substructure, as depicted in Figure 9-3. The structure-indicated method of 9.2.2 may append such a CAS substructure, or may rely on multi-frame alignment to safeguard CAS bits. + +### **12.2 Support of CCS** + +CCS may be carried in one or more timeslots of the TDM signal as an asynchronous message flow, frequently as high level data link control (HLDC) frames. + +Such channels may be idle for long periods. In such cases, the HDLC mode defined in Appendix I may be employed. + +## **13 Security considerations** + +Security aspects have not been addressed in this Recommendation. + +## **Appendix I** + +## **Optional processing of HDLC-based CCS signals** + +The HDLC mode may be utilized in conjunction with Structure-Aware TDM transport to efficiently transport trunk associated HDLC-based CCS, such as SS7 [21] and ISDN PRI signalling [22]. This mechanism is not intended for general HDLC payloads, and only supports HDLC messages that are shorter than the maximum PDU size. + +The HDLC mode should only be used when the majority of the bandwidth of the HDLC stream is occupied by idle flags. Otherwise, the CCS channel should be treated as an ordinary timeslot. + +The HDLC-IP interworking shall transparently pass all HDLC data and control messages over a separate interworking flow. + +At ingress the sender monitors flags until a frame is detected. The contents of the frame are collected and the frame check sequence (FCS) tested. If the FCS is incorrect the frame is discarded, otherwise the frame is sent after initial or final flags and FCS have been discarded and zero removal (as per 2.6/Q.921 [32]) has been performed. At egress, zero insertion is performed, the FCS is recalculated, and a valid HDLC frame reconstituted. + +## **Appendix II** + +## **IP network performance metrics** + +This appendix discusses impairments to the emulated TDM service caused by errors within the IP network. It primarily addresses the relationships between the performance parameters of the underlying IP network and service impairment metrics for TDM services, namely errored seconds and severely errored seconds as defined in ITU-T Rec. G.826 [8], and availability ratio as defined in ITU-T Rec. G.827 [33]. In addition, specific performance measures for voice channels are discussed. + +### **II.1 Errors in the IP network that impact TDM service** + +Whenever the IWF needs to generate AIS or filler data due to not having true TDM data available, TDM performance metrics will be impacted. This may occur due to three distinguishable IP network degradations, namely: + +- 1) packet loss in the IP network; +- 2) packets being discarded due to detected errors; and +- 3) packets discarded due to jitter buffer overflow/underflow. + +These three degradations are quantifiable using metrics defined for packet switched networks in other ITU-T Recommendations, such as ITU-T Rec. G.1020 [34]. + +ITU-T Rec. G.1020 defines packet network and terminal performance parameters that reflect the perceived quality of the speech and other voiceband applications. It is largely focused on quality impairments resulting from delay variation and packet loss which are peculiar to IP and other packet-based technologies, and that do not appear in traditional TDM networks. Although TDM services are not directly addressed by ITU-T Rec. G.1020, some of the metrics defined therein are applicable to voice channels carried by TDM. + +#### **II.1.1 Packet loss ratio** + +IP packet loss ratio is defined in ITU-T Rec. Y.1540 [25]. Each lost packet leads to a burst of bit errors in the reconstructed TDM stream. + +#### **II.1.2 Packet delay variation** + +IP packet delay variation (PDV) is defined in ITU-T Rec. Y.1540. Since PDV is used to set the jitter buffer size, these packets may either arrive too late or too early to be accommodated. Such packets will be discarded and treated as lost, resulting once again in a burst of bit errors in the reconstructed TDM stream. In some implementations, all misordered packets will be discarded and treated as lost. + +#### **II.1.3 Packet error ratio** + +IP packet error ratio is defined in ITU-T Rec. Y.1540. Bit errors induced in the IP network will normally be detected by a layer-2 error detection mechanism, causing the packet to be discarded. This leads to a burst of bit errors in the TDM stream. More rarely a packet containing bit errors may evade error detection and contribute directly to TDM bit errors. + +#### **II.1.4 Overall packet loss** + +Overall packet loss ratio is defined in ITU-T Rec. G.1020 [34]. Each of the above errors (packet loss, packet error, and excess packet delay variation) may result in lost or discarded packets, causing a burst of bit errors in the TDM service. ITU-T Rec. G.1020 defines a composite measure for these types of errors in an IP network, termed "overall packet loss". + +In order to maintain timing integrity, the egress IWF inserts the proper amount of filler data into the reconstructed TDM stream. The data to be inserted is implementation dependent. + +### **II.2 Relationship to TDM service impairment metrics** + +ITU-T Rec. G.826 [8] defines "errored seconds" and "severely errored seconds", performance parameters related to the integrity of the data being transferred across the TDM circuit. The discussion below relates these TDM performance measures to the overall packet loss ratio in the IP network. + +#### **II.2.1 Errored seconds ratio** + +An errored second is a one-second interval with one or more bit errors. ITU-T Rec. G.826 specifies end-to-end objectives for the percentage of seconds that may be errored for each TDM type. + +If the majority of IP packets lost or discarded are isolated events, then each individual packet lost or discarded may result in an errored second, and only an extremely small overall packet loss ratio is commensurate with G.826 constraints. If, on the other hand, most of the packet loss occurs in bursts, many consecutive loss events contribute to the same errored second, and a much higher packet loss ratio is allowed. Quantitative modelling of such behaviour can be performed using network models, such as those described in Appendix I/G.1020. + +#### **II.2.2 Severely errored seconds requirement** + +A severely errored second is defined as a one-second period where 30% or more of the blocks of TDM data received are errored. ITU-T Rec. G.826 specifies end-to-end objectives for the percentage of seconds that may be severely errored. + +If the majority of IP packets lost or discarded are in bursts, and these bursts are of sufficient duration, then severely errored seconds may result in the reconstructed TDM stream. On the other hand, isolated loss events lead to low severely errored second ratios. Once again network modelling may shed light on the numerical relationship between packet loss and G.826 conformance. + +### **II.3 Availability requirements** + +The "unavailable state", as defined in ITU-T Rec. G.826, is entered at the start of a period of 10 consecutive severely errored seconds. The "available state" is resumed at the start of a period of 10 consecutive seconds, none of which are severely errored. + +The availability of an IP network is defined in ITU-T Rec. Y.1540 [25] and can be correlated with the definition of TDM availability. + +### **II.4 Voice quality requirements** + +Depending upon the packet loss rate of the underlying IP network, TDM carried over IP networks may not conform to the error objectives of ITU-T Rec. G.826. + +However, voice traffic carried in TDM streams may still be able to meet standard voice quality objectives. Of particular importance are the reduction in voice quality as specified in ITU-T Recs P.800 [35] and P.862 [36], and the delay requirements set forth in ITU-T Rec. G.114 [7]. + +It is generally recognized that most applications will have acceptable performance when the one-way delay is lower than 150 ms, assuming adequate echo control is provided (higher delays may be acceptable in some cases). Network planning and configuration of jitter buffers must take this constraint into account. + +Packet loss in voice traffic can cause gaps or artefacts that result in choppy, garbled or even unintelligible speech. Subjective measures of voice quality are given in ITU-T Rec. P.800 [35] and objective measures in ITU-T Rec. P.862 [36]. TDM-IP interworking must ensure that perceptual voice quality be similar to that of the PSTN even in the presence of a reasonable overall packet loss ratio. + +## **Appendix III** + +## **Suggested payload sizes for structure-agnostic transport** + +Structure-agnostic transport implementations should be capable of supporting the following payload sizes: + +- synchronous serial data – 64 bytes. +- E1 – 256 bytes. +- DS1 – 192 bytes. +- E3 and DS3 – 1024 bytes. +- Payload sizes that are multiples of 47 bytes may be used in conjunction with unstructured ATM-CES [30]. + +Any payload size that does not lead to packet fragmentation may be used after having been agreed upon by ingress and egress IWFs. + +By choosing sizes that are multiples or integer divisors of FAS periods, one may increase the tolerance to packet loss. + +## **Appendix IV** + +## **Suggested number of AAL 1 SAR PDUs per packet** + +The number of PDUs per IP packet is preconfigured and typically chosen taking into account latency and bandwidth constraints. Using a single PDU reduces latency to a minimum, but incurs the highest overhead. Suggested values are between 1 and 8 PDUs per packet for E1 and DS1 circuits, and between 5 and 15 PDUs per packet for E3 and DS3 circuits. + +Using eight or more PDUs per packet invalidates the use of the AAL 1 sequence number mechanism, and hence complicates interworking with ATM-based CES systems. + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|--------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/Y/T-REC-Y.1560-200309-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/Y/T-REC-Y.1560-200309-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..939eb6a57fac47a375526475ba6c31bf67e08b30 --- /dev/null +++ b/marked/Y/T-REC-Y.1560-200309-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:52a289bbb49d106b16f646b5050f62e5c7cbe1bb201f8c767547c3039abbf359 +size 8245 diff --git a/marked/Y/T-REC-Y.1560-200309-I_PDF-E/35a7554182eb055209552843f341a1ae_img.jpg b/marked/Y/T-REC-Y.1560-200309-I_PDF-E/35a7554182eb055209552843f341a1ae_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..afc959e71c82387afe4dfd452a39d6c4301a90ab --- /dev/null +++ b/marked/Y/T-REC-Y.1560-200309-I_PDF-E/35a7554182eb055209552843f341a1ae_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:deeda7bdf3085210e690ff8a5126157f78f1899342625121ce669883e0286963 +size 95362 diff --git a/marked/Y/T-REC-Y.1560-200309-I_PDF-E/a33da0f14e456f92539ce3e9b7d81f9a_img.jpg b/marked/Y/T-REC-Y.1560-200309-I_PDF-E/a33da0f14e456f92539ce3e9b7d81f9a_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..3e8d8c15cdd5a8e983e0bdd7f9bf48c4b775c78d --- /dev/null +++ b/marked/Y/T-REC-Y.1560-200309-I_PDF-E/a33da0f14e456f92539ce3e9b7d81f9a_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:569345e5dd08a61aac62611158aa3674825417710d260f470ed328fd25c8883b +size 101149 diff --git a/marked/Y/T-REC-Y.1560-200309-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg b/marked/Y/T-REC-Y.1560-200309-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..108aa147ebc3f8996c4115ecbd229aa2220ec7cc --- /dev/null +++ b/marked/Y/T-REC-Y.1560-200309-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:7871b6d520a0a06df4779a84d8a3081e7c2fd7045c96cf4bba7bcb8b2f333c0b +size 140209 diff --git a/marked/Y/T-REC-Y.1560-200309-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg b/marked/Y/T-REC-Y.1560-200309-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..90f47d15440acc4c881a296ca843017bf00a0812 --- /dev/null +++ b/marked/Y/T-REC-Y.1560-200309-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:31b4ecb0ed0693265c18e0486c441a01c55b92eddc524b4e56b80f7870f4e79d +size 46580 diff --git a/marked/Y/T-REC-Y.1560-200309-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg b/marked/Y/T-REC-Y.1560-200309-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..ed1e971c8e27cadcd6150a94a179d25fc53cd107 --- /dev/null +++ b/marked/Y/T-REC-Y.1560-200309-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:36fd5050c5ceb1b00fdc1f2da577057aca9ad3ddcfea96c4211d4f9a8c2e9341 +size 62165 diff --git a/marked/Y/T-REC-Y.1560-200309-I_PDF-E/ff0952ef692c9d960ce5f6708bcc9711_img.jpg b/marked/Y/T-REC-Y.1560-200309-I_PDF-E/ff0952ef692c9d960ce5f6708bcc9711_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..faf5d3433caa039207d71310259085d830676d63 --- /dev/null +++ b/marked/Y/T-REC-Y.1560-200309-I_PDF-E/ff0952ef692c9d960ce5f6708bcc9711_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:1db2a86da10b579ccc4949f594a01ea712904f5259190541f3f746ca8a13ddad +size 61752 diff --git a/marked/Y/T-REC-Y.1560-200309-I_PDF-E/raw.md b/marked/Y/T-REC-Y.1560-200309-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..8f4b827769c08937b3cbd6e9bf14981ef01669d3 --- /dev/null +++ b/marked/Y/T-REC-Y.1560-200309-I_PDF-E/raw.md @@ -0,0 +1,476 @@ + + +![ITU logo: a globe with the letters ITU inside, and a lightning bolt striking the globe.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU inside, and a lightning bolt striking the globe. + +INTERNATIONAL TELECOMMUNICATION UNION + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**Y.1560** + +(09/2003) + +SERIES Y: GLOBAL INFORMATION +INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS +AND NEXT GENERATION NETWORKS + +Internet protocol aspects – Quality of service and network +performance + +# --- **Parameters for TCP connection performance in the presence of middleboxes** + +ITU-T Recommendation Y.1560 + +--- + +## ITU-T Y-SERIES RECOMMENDATIONS **GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT GENERATION NETWORKS** + +| | | +|--------------------------------------------------------------------|----------------------| +| GLOBAL INFORMATION INFRASTRUCTURE | | +| General | Y.100–Y.199 | +| Services, applications and middleware | Y.200–Y.299 | +| Network aspects | Y.300–Y.399 | +| Interfaces and protocols | Y.400–Y.499 | +| Numbering, addressing and naming | Y.500–Y.599 | +| Operation, administration and maintenance | Y.600–Y.699 | +| Security | Y.700–Y.799 | +| Performances | Y.800–Y.899 | +| INTERNET PROTOCOL ASPECTS | | +| General | Y.1000–Y.1099 | +| Services and applications | Y.1100–Y.1199 | +| Architecture, access, network capabilities and resource management | Y.1200–Y.1299 | +| Transport | Y.1300–Y.1399 | +| Interworking | Y.1400–Y.1499 | +| Quality of service and network performance | Y.1500–Y.1599 | +| Signalling | Y.1600–Y.1699 | +| Operation, administration and maintenance | Y.1700–Y.1799 | +| Charging | Y.1800–Y.1899 | +| NEXT GENERATION NETWORKS | | +| Frameworks and functional architecture models | Y.2000–Y.2099 | +| Quality of Service and performance | Y.2100–Y.2199 | +| Service aspects: Service capabilities and service architecture | Y.2200–Y.2249 | +| Service aspects: Interoperability of services and networks in NGN | Y.2250–Y.2299 | +| Numbering, naming and addressing | Y.2300–Y.2399 | +| Network management | Y.2400–Y.2499 | +| Network control architectures and protocols | Y.2500–Y.2599 | +| Security | Y.2700–Y.2799 | +| Generalized mobility | Y.2800–Y.2899 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# **ITU-T Recommendation Y.1560** + +# **Parameters for TCP connection performance in the presence of middleboxes** + +## **Summary** + +This Recommendation defines the end-to-end Transmission Control Protocol (TCP) performance in terms of speed, accuracy, and dependability in an IP-based network with middleboxes, which are nodes terminating TCP connections. + +## **Source** + +ITU-T Recommendation Y.1560 was approved by ITU-T Study Group 13 (2001-2004) under the ITU-T Recommendation A.8 procedure on 13 September 2003. + +## **Keywords** + +Availability, Internet Protocol (IP), Transmission Control Protocol (TCP), TCP performance. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g. interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database. + +© ITU 2004 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## CONTENTS + +| | Page | +|-------------------------------------------------|-------------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 4 Abbreviations..... | 1 | +| 5 Reference model ..... | 2 | +| 5.1 Layered model ..... | 2 | +| 5.2 Reference configuration ..... | 2 | +| 5.3 Reference events..... | 3 | +| 6 Performance parameters ..... | 4 | +| 6.1 Speed parameters..... | 4 | +| 6.2 Accuracy and dependability parameters..... | 5 | +| 6.3 Availability parameters ..... | 6 | +| Appendix I – Middlebox ..... | 6 | +| I.1 Introduction ..... | 6 | +| I.2 Factors that affect TCP performance..... | 6 | +| I.3 References ..... | 6 | +| Appendix II – Effectiveness of middleboxes..... | 8 | +| Appendix III – Information on throughput ..... | 8 | +| III.1 Issue to define TCP throughput..... | 8 | +| III.2 Data communication throughput ..... | 9 | +| III.3 Overall communication throughput..... | 9 | +| Appendix IV – Bibliography..... | 9 | + + + +# ITU-T Recommendation Y.1560 + +# Parameters for TCP connection performance in the presence of middleboxes + +# 1 Scope + +This Recommendation defines the end-to-end, point-to-point Transmission Control Protocol (TCP) performance in terms of speed, accuracy, and dependability in an IP-based network with middleboxes, which are nodes terminating TCP connections. TCP performance is specified in an end-to-end timeline of TCP connections composed of three phases: connection establishment, data communication, and connection clearing. Availability performance is also one of TCP performance. The TCP connection performance that a user can experience through an application can be measured by monitoring the IP-based network. Performance interaction between the TCP and IP layers is for further study. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- [1] ITU-T Recommendation I.350 (1993), *General aspects of quality of service and network performance in digital networks, including ISDNs*. +- [2] ITU-T Recommendation Y.1540 (2002) (formerly ITU-T Rec. I.380), *Internet protocol data communication service – IP packet transfer and availability performance parameters*. +- [3] ITU-T Recommendation Y.1541 (2002), *Network performance objectives for IP-based services*. +- [4] IETF RFC 793 (1981) – *Transmission Control Protocol (TCP)*. + +# 3 Definitions + +This Recommendation defines the following terms: + +- 3.1 end-to-end TCP performance:** Performance on TCP layer from SRC to DST. +- 3.2 ports:** The portion of a socket that specifies which logical input or output channel of a process is associated with the data. + +# 4 Abbreviations + +This Recommendation uses the following abbreviations. + +| | | +|------|-----------------------------| +| ACK | Acknowledgment | +| DST | Destination host | +| FIN | Finish | +| FTP | File Transfer Protocol | +| HTTP | HyperText Transfer Protocol | + +| | | +|-------|----------------------------------------------------------------------------------| +| IETF | Internet Engineering Task Force | +| IP | Internet Protocol | +| ISDN | Integrated Services Digital Network | +| ITU-T | International Telecommunication Union – Telecommunication Standardization Sector | +| LL | Lower Layers, protocols and technology supporting the IP layer | +| MP | Measurement Point | +| SMTP | Simple Mail Transfer Protocol | +| SRC | Source host | +| SYN | Initiation flag of TCP connection | + +# 5 Reference model + +## 5.1 Layered model + +Figure 1 illustrates the layered nature of the performance of a TCP connection with a middlebox, which terminates TCP connections. TCP connection is a logical communication path established between a pair of ports and initialized on each side. The performance provided to TCP service users depends on the performance of the IP layer and other layers. + +![Figure 1/Y.1560 – Layered model of performance for TCP connection with a middlebox – example. The diagram shows a layered architecture across five horizontal sections. 1. High layer performance: Contains boxes for '(HTTP) (FTP) (SMTP)' at the Source Host (SRC) and Destination Host (DST). 2. TCP connection performance: Contains 'TCP layer' boxes. A dashed line connects the TCP layer of the SRC to the TCP layer of the Destination Host, passing through a 'Middle box' which terminates the connection. Arrows labeled 'TCP connections' point from the high layer to the TCP layers. 3. IP packet layer service performance (Y.1540): Contains 'IP layer' boxes for SRC, Middle box, and Destination Host. 4. Lower layer performance (3 instances): Contains 'LL' (Lower Layers) boxes for SRC, Middle box, and Destination Host. 5. Network components: A vertical sequence of components with upward arrows: SRC, Link, Middle box, Link, Router, Link, DST. The diagram is divided by vertical dashed lines and horizontal dashed lines separating the performance layers.](35a7554182eb055209552843f341a1ae_img.jpg) + +Figure 1/Y.1560 – Layered model of performance for TCP connection with a middlebox – example. The diagram shows a layered architecture across five horizontal sections. 1. High layer performance: Contains boxes for '(HTTP) (FTP) (SMTP)' at the Source Host (SRC) and Destination Host (DST). 2. TCP connection performance: Contains 'TCP layer' boxes. A dashed line connects the TCP layer of the SRC to the TCP layer of the Destination Host, passing through a 'Middle box' which terminates the connection. Arrows labeled 'TCP connections' point from the high layer to the TCP layers. 3. IP packet layer service performance (Y.1540): Contains 'IP layer' boxes for SRC, Middle box, and Destination Host. 4. Lower layer performance (3 instances): Contains 'LL' (Lower Layers) boxes for SRC, Middle box, and Destination Host. 5. Network components: A vertical sequence of components with upward arrows: SRC, Link, Middle box, Link, Router, Link, DST. The diagram is divided by vertical dashed lines and horizontal dashed lines separating the performance layers. + +Y.1560\_F01 + +**Figure 1/Y.1560 – Layered model of performance for TCP connection with a middlebox – example** + +## 5.2 Reference configuration + +Figure 2 illustrates the relationship between reference events and measurement points for a TCP connection. When there is no middlebox, there are only two edge measurement points. + +![Figure 2/Y.1560 – Relationship between reference events and measurement points. The diagram shows a network architecture with four layers: Higher-protocol layer, TCP layer, IP layer, and Layer. A Middlebox is positioned between the TCP and IP layers. The IP network cloud is represented by a large oval. TCP connections are shown as dashed lines passing through the Middlebox. IP flows are shown as solid lines passing through the IP layer. Reference events are marked as Ingress event and Egress event, with measurement points (MP) indicated. The diagram also shows an (exit) and (entry) point for the IP network cloud. The label Y.1560_F02 is present in the bottom right corner.](ebff22fb5dd6f50a90e44dca0f82f285_img.jpg) + +Figure 2/Y.1560 – Relationship between reference events and measurement points. The diagram shows a network architecture with four layers: Higher-protocol layer, TCP layer, IP layer, and Layer. A Middlebox is positioned between the TCP and IP layers. The IP network cloud is represented by a large oval. TCP connections are shown as dashed lines passing through the Middlebox. IP flows are shown as solid lines passing through the IP layer. Reference events are marked as Ingress event and Egress event, with measurement points (MP) indicated. The diagram also shows an (exit) and (entry) point for the IP network cloud. The label Y.1560\_F02 is present in the bottom right corner. + +**Figure 2/Y.1560 – Relationship between reference events and measurement points** + +## 5.3 Reference events + +Figure 3 illustrates the end-to-end timelines of some TCP connections. Each end-to-end timeline has a connection establishment phase, data communication phase, and connection clearing phase. + +The connection establishment phase is the duration between the time that the SYN packet is sent from Ingress MP to middlebox, and ACK packet from middlebox is received at Egress MP. + +The data communication phase is the duration between the time that the first data request packet is sent from Ingress MP to middlebox, and ACK packet from Ingress MP for the last data transfer packet is received at middlebox. + +The connection clearing phase is the duration between the time that the FIN packet is sent from Ingress MP to middlebox, and FIN+ACK packet from middlebox is received at Egress MP. + +The overall communication phase is the duration between the time that the SYN packet is sent from Ingress MP to middlebox, and FIN+ACK packet from middlebox is received at Egress MP. Overall communication phase consists of communication establishment, data communication, and connection clearing phases. + +TCP performance reference events and parameters are defined based on these phases and flows. The end-to-end timeline of TCP connections depends on the TCP version. To define the end-to-end timeline, one should specify the TCP version. + +NOTE 1 – TCP version means IETF RFC 793, Reno, Tahoe, and so on. + +NOTE 2 – Figure 3 is one sample. There are some ACK handling ways in middlebox. See Appendix I. + +![Sequence diagram showing end-to-end timelines of TCP connections between Ingres MP, Middlebox, and Egress MP. The diagram is divided into three phases: connection establishment, data communication, and connection clearing. The overall communication spans all three phases.](a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg) + +The diagram illustrates the sequence of events for a TCP connection across three entities: Ingres MP, Middlebox, and Egress MP. The timeline is divided into three main phases: connection establishment, data communication, and connection clearing. The overall communication spans all three phases. + +**Connection Establishment Phase:** + +- Ingres MP sends a SYN packet to Middlebox. +- Middlebox sends a SYN+ACK packet to Ingres MP. +- Ingres MP sends an ACK packet to Middlebox. +- Middlebox sends a SYN packet to Egress MP. +- Egress MP sends a SYN+ACK packet to Middlebox. +- Middlebox sends an ACK packet to Egress MP. + +**Data Communication Phase:** + +- Ingres MP sends data packet A for request to Middlebox. +- Middlebox sends data packet A for request to Egress MP. +- Egress MP sends an ACK packet for packet A to Middlebox. +- Middlebox sends data packet B to Ingres MP. +- Middlebox sends data packet C to Ingres MP. +- Ingres MP sends an ACK packet for packet C to Middlebox. +- Middlebox sends an ACK packet for packet C to Egress MP. +- Middlebox sends data packet D to Ingres MP. +- Ingres MP sends an ACK packet for packet D to Middlebox. +- Middlebox sends an ACK packet for packet D to Egress MP. + +**Connection Clearing Phase:** + +- Ingres MP sends a FIN packet to Middlebox. +- Middlebox sends a FIN+ACK packet to Ingres MP. +- Ingres MP sends a FIN packet to Middlebox. +- Middlebox sends a FIN+ACK packet to Ingres MP. +- Middlebox sends a FIN packet to Egress MP. +- Egress MP sends a FIN+ACK packet to Middlebox. +- Middlebox sends a FIN packet to Egress MP. +- Egress MP sends a FIN+ACK packet to Middlebox. + +Overall communication spans the entire duration from the first SYN packet to the last FIN+ACK packet. + +Y.1560\_F03 + +Sequence diagram showing end-to-end timelines of TCP connections between Ingres MP, Middlebox, and Egress MP. The diagram is divided into three phases: connection establishment, data communication, and connection clearing. The overall communication spans all three phases. + +**Figure 3/Y.1560 – End-to-end timelines of TCP connections** + +# 6 Performance parameters + +Table 1 illustrates the application of the three generic performance criteria to each of the three TCP functions. Availability performance is also one of TCP performance derived from the three generic performance parameters. + +## 6.1 Speed parameters + +### 6.1.1 Connection establishment delay + +The connection establishment delay is the duration between the time that the SYN packet is sent from Ingress MP to middlebox, and ACK packet from middlebox is received at Egress MP. + +The connection establishment delay is the duration of the connection establishment phase in Figure 3. + +### 6.1.2 Data communication throughput + +The definition of throughput parameters for data communication is for further study. + +NOTE – See Appendix III.2. + +**Table 1/Y.1560 – Generic performance criteria for TCP connection functions** + +| | | Speed | | Accuracy | Dependability | +|----------------|--------------------------|--------------------------------|----------------------------------|--------------------------------------------|----------------------------------------------| +| TCP connection | Connection establishment | Connection establishment delay | Overall communication throughput | Connection establishment error probability | Connection establishment failure probability | +| | Data communication | Data communication throughput | | – | – | +| | Connection clearing | Connection clearing delay | | Premature disconnect probability | Connection clearing failure probability | + +### 6.1.3 Connection clearing delay + +The connection clearing delay is the duration between the time that the FIN packet is sent from Ingress MP to middlebox, and FIN+ACK packet from middlebox is received at Egress MP. + +The connection clearing delay is the duration of the connection clearing phase in Figure 3. The definition of clearing delay depends on the TCP version and is for further study. + +### 6.1.4 Overall communication throughput + +The definition of throughput parameters for overall communication is for further study. + +NOTE – See Appendix III.3. + +## 6.2 Accuracy and dependability parameters + +### 6.2.1 Connection establishment error probability + +The connection establishment error probability is the ratio of the number of connection establishment attempts that result in an error in connection establishment to the total number of connection establishment attempts in a measurement period. + +### 6.2.2 Connection establishment failure probability + +The connection establishment failure probability is the ratio of the number of connection establishment attempts that fail to establish a connection to the total number of connection establishment attempts in a measurement period. + +### 6.2.3 Premature disconnect probability + +The definition of premature disconnect probability is for further study. + +### 6.2.4 Connection clearing failure probability + +The connection release failure probability is the ratio of connection clearing failures to the total number of connection release attempts in a measurement period. + +## 6.3 Availability parameters + +Decisions on the appropriate primary performance parameters, outage threshold and algorithms for its definition require further detailed study. TCP service unavailability may be one of availability performance parameters. + +# Appendix I + +## Middlebox + +## I.1 Introduction + +Middleboxes are being discussed by IETF [1]. The main ones are: i) packet filtering firewall, ii) application proxy and iii) Network Address Translation (NAT). + +- i) A packet filtering firewall drops packets that are not permitted to pass through. TCP connections are not terminated. +- ii) An application proxy terminates a TCP connection, and acts for the connection to the outside. HTTP proxy, Wireless Application Protocol (WAP) proxy and performance enhancing proxy (PEP) are examples of application proxies. +- iii) NATs translate private IP addresses to/from global IP addresses. TCP connections are not terminated. + +## I.2 Factors that affect TCP performance + +The following factors affect TCP performance when there are middleboxes in the network: + +- a) An increase in delay caused by passing through a middlebox (Figure I.1); +- b) an increase in throughput as a result of the middlebox (Figure I.2). + +For the middleboxes introduced in I.1: + +- i) packet filtering firewalls involve factor a; +- ii) application proxies involve factors a and b; +- iii) NATs involve factor a. + +Other middleboxes also involve these two factors. + +## I.3 References + +- [1] RFC 3234 (2002), *Middleboxes: Taxonomy and Issues*. +- [2] RFC 3303 (2002), *Middlebox communication architecture and framework*. +- [3] RFC 3135 (2001), *Performance Enhancing Proxies Intended to Mitigate Link-Related Degradations*. +- [4] WAP, Home Pages, + +![Sequence diagram showing packet A's path through a middlebox and two egress multiplexers, illustrating an increase in delay.](af7916c89a458fdab6c3f443217388ae_img.jpg) + +This sequence diagram illustrates the flow of 'data packet A' and its corresponding 'ACK packet for A' through three network components: Ingress MP, Middlebox, and Egress MP. The diagram is divided into two parts. In the left part, 'data packet A' is sent from the Ingress MP to the Middlebox. A vertical double-headed arrow labeled 'delay' indicates the time spent in the Middlebox. The packet then moves to the first Egress MP. The 'ACK packet for A' is sent back from the first Egress MP to the Middlebox, and another vertical double-headed arrow labeled 'delay' indicates the time spent in the Middlebox before it is sent back to the Ingress MP. In the right part, 'data packet A' is sent directly from the Ingress MP to the second Egress MP. The 'ACK packet for A' is sent back from the second Egress MP to the Ingress MP. The label 'Y.1560\_FI.1' is located at the bottom right of the diagram. + +Sequence diagram showing packet A's path through a middlebox and two egress multiplexers, illustrating an increase in delay. + +Y.1560\_FI.1 + +**Figure I.1/Y.1560 – Increase in delay** + +![Sequence diagram showing packets A and B being processed by a middlebox and two egress multiplexers, illustrating the effect of PEP.](ff0952ef692c9d960ce5f6708bcc9711_img.jpg) + +This sequence diagram illustrates the flow of two data packets, 'data packet A' and 'data packet B', and their corresponding ACK packets through three network components: Ingress MP, Middlebox, and Egress MP. The diagram is divided into two parts. In the left part, 'data packet A' is sent from the Ingress MP to the Middlebox, followed by 'ACK packet for A' returning to the Ingress MP. Then 'data packet B' is sent from the Ingress MP to the Middlebox, followed by 'ACK packet for B' returning to the Ingress MP. In the middle part, 'data packet A' is sent from the Middlebox to the first Egress MP, followed by 'ACK packet for A' returning to the Middlebox. Then 'data packet B' is sent from the Middlebox to the first Egress MP, followed by 'ACK packet for B' returning to the Middlebox. In the right part, 'data packet A' is sent directly from the Ingress MP to the second Egress MP, followed by 'ACK packet for A' returning to the Ingress MP. Then 'data packet B' is sent directly from the Ingress MP to the second Egress MP, followed by 'ACK packet for B' returning to the Ingress MP. The label 'Y.1560\_FI.2' is located at the bottom right of the diagram. + +Sequence diagram showing packets A and B being processed by a middlebox and two egress multiplexers, illustrating the effect of PEP. + +Y.1560\_FI.2 + +**Figure I.2/Y.1560 – Effect of PEP** + +# Appendix II + +## Effectiveness of middleboxes + +The effectiveness of middleboxes is obtained by comparing the cases where middleboxes are and are not used in the network. Therefore, it is important to consider the case without middleboxes, which is shown in Figure II.1. The parameters described in clause 5 should be determined and evaluated when middleboxes are not in the network. + +![Layered model of performance for TCP connection without a middlebox – example](a33da0f14e456f92539ce3e9b7d81f9a_img.jpg) + +The diagram illustrates a layered model of performance for a TCP connection without a middlebox. It is organized into five horizontal layers, separated by dashed lines, and a vertical dashed line on the left side. + +- High layer performance:** Contains two boxes labeled "(HTTP) (FTP) (SMTP)". +- TCP connection performance:** Contains two boxes labeled "TCP layer". A dashed line labeled "TCP connection" connects the two "TCP layer" boxes. +- IP packet layer service performance (Y.1540):** Contains four boxes labeled "IP layer". +- Lower layer performance (3 instances):** Contains three boxes labeled "LL". +- Network components:** Contains labels for "Source Host (SRC)", "Link", "Router", "Link", "Router", "Link", and "Destination Host (DST)". + +Arrows indicate the flow of data from the Source Host (SRC) through the network components (Link, Router, Link, Router, Link) to the Destination Host (DST). The "TCP connection" is established between the two "TCP layer" boxes. The "IP layer" boxes are connected to the "LL" boxes, which are connected to the network components. + +Y.1560\_FII.1 + +Layered model of performance for TCP connection without a middlebox – example + +**Figure II.1/Y.1560 – Layered model of performance for TCP connection without a middlebox – example** + +# Appendix III + +## Information on throughput + +## III.1 Issue to define TCP throughput + +Following aspects affect the definition of TCP throughput. + +### *Version dependency* + +Various TCP versions exist, and each version acts differently on the data communication phase. Therefore, each TCP throughput version has to be defined individually. This is for further study. + +### *Client aspects* + +TCP throughput depends on client's setting and performance. To define TCP throughput we have to consider client aspects and this is beyond the scope of this Recommendation. + +## **III.2 Data communication throughput** + +Data communication throughput is expressed by dividing the total number of bytes sent in the data communication phase by the time taken between the first packet's departure and the last packet's arrival. Data communication throughputs of the upstream and downstream directions are specified. Performance parameters for evaluating the variation during data communication, like FTP bulk communication, are also necessary. + +## **III.3 Overall communication throughput** + +Overall communication throughput is expressed by dividing the total number of bytes sent in overall communication by the time taken between the first packet's departure in connection establishment and the last packet's arrival in connection clearing. Connection throughputs of the upstream and downstream directions are specified. Overall communication throughput is a measure of the performance of the whole connection including connection establishment, data communication, and connection clearing. + +# **Appendix IV** + +## **Bibliography** + +RFC 2330 (1998), *Framework for IP Performance Metrics*. + +RFC 3148 (2001), *A Framework for Defining Empirical Bulk Transfer Capacity Metrics*. + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|--------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series B | Means of expression: definitions, symbols, classification | +| Series C | General telecommunication statistics | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | TMN and network maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks and open system communications | +| Series Y | Global information infrastructure, Internet protocol aspects and Next Generation Networks | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/Y/T-REC-Y.1563-200901-I_PDF-E/raw.md b/marked/Y/T-REC-Y.1563-200901-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..fdb957f40e4b65fe6e35acc83f3bea6ef8fb423f --- /dev/null +++ b/marked/Y/T-REC-Y.1563-200901-I_PDF-E/raw.md @@ -0,0 +1,1447 @@ + + +I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +## Y.1563 + +(01/2009) + +SERIES Y: GLOBAL INFORMATION +INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS +AND NEXT-GENERATION NETWORKS + +Internet protocol aspects – Quality of service and network +performance + +# --- **Ethernet frame transfer and availability performance** + +Recommendation ITU-T Y.1563 + +![ITU logo](84a1d09fb489061482111515543b60dc_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with a red lightning bolt striking it, and the text "ITU" in blue, with "International Telecommunication Union" in smaller blue text below it. + +ITU logo + +# ITU-T Y-SERIES RECOMMENDATIONS **GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT- GENERATION NETWORKS** + +| | | +|--------------------------------------------------------------------|----------------------| +| GLOBAL INFORMATION INFRASTRUCTURE | | +| General | Y.100–Y.199 | +| Services, applications and middleware | Y.200–Y.299 | +| Network aspects | Y.300–Y.399 | +| Interfaces and protocols | Y.400–Y.499 | +| Numbering, addressing and naming | Y.500–Y.599 | +| Operation, administration and maintenance | Y.600–Y.699 | +| Security | Y.700–Y.799 | +| Performances | Y.800–Y.899 | +| INTERNET PROTOCOL ASPECTS | | +| General | Y.1000–Y.1099 | +| Services and applications | Y.1100–Y.1199 | +| Architecture, access, network capabilities and resource management | Y.1200–Y.1299 | +| Transport | Y.1300–Y.1399 | +| Interworking | Y.1400–Y.1499 | +| Quality of service and network performance | Y.1500–Y.1599 | +| Signalling | Y.1600–Y.1699 | +| Operation, administration and maintenance | Y.1700–Y.1799 | +| Charging | Y.1800–Y.1899 | +| NEXT GENERATION NETWORKS | | +| Frameworks and functional architecture models | Y.2000–Y.2099 | +| Quality of Service and performance | Y.2100–Y.2199 | +| Service aspects: Service capabilities and service architecture | Y.2200–Y.2249 | +| Service aspects: Interoperability of services and networks in NGN | Y.2250–Y.2299 | +| Numbering, naming and addressing | Y.2300–Y.2399 | +| Network management | Y.2400–Y.2499 | +| Network control architectures and protocols | Y.2500–Y.2599 | +| Security | Y.2700–Y.2799 | +| Generalized mobility | Y.2800–Y.2899 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# **Recommendation ITU-T Y.1563** + +# **Ethernet frame transfer and availability performance** + +## **Summary** + +Recommendation ITU-T Y.1563 defines parameters that may be used in specifying and assessing the performance of speed, accuracy, dependability and availability of Ethernet frame transfer of an Ethernet communication service. The defined parameters apply to end-to-end, point-to-point connections and multipoint connectivity in the Ethernet layer and to the network portions that provide, or contribute to the provision of, such service in accordance with the normative references specified in clause 2. + +###### **Source** + +Recommendation ITU-T Y.1563 was approved on 13 January 2009 by ITU-T Study Group 12 (2009-2012) under Recommendation ITU-T A.8 procedures. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2009 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## CONTENTS + +| | | Page | +|---|--------------------------------------------------------------------------------------------------|------| +| 1 | Scope ..... | 1 | +| 2 | References..... | 3 | +| 3 | Definitions ..... | 4 | +| | 3.1 Terms defined elsewhere..... | 4 | +| | 3.2 Terms defined in this Recommendation..... | 4 | +| 4 | Abbreviations and acronyms ..... | 5 | +| 5 | Conventions ..... | 6 | +| 6 | Layered model of performance for Ethernet service ..... | 6 | +| 7 | Ethernet service performance model, reference events and outcomes ..... | 7 | +| | 7.1 Network components..... | 7 | +| | 7.2 Links and network sections ..... | 7 | +| | 7.3 Measurement points and measurable sections..... | 8 | +| | 7.4 Ethernet frame transfer reference events (FREs) ..... | 8 | +| | 7.5 Ethernet frame transfer outcomes..... | 10 | +| | 7.6 Frame qualifications ..... | 13 | +| 8 | Ethernet frame transfer performance parameters ..... | 14 | +| | 8.1 Point-to-point Ethernet frame transfer delay (FTD)..... | 15 | +| | 8.2 Point-to-multipoint Ethernet frame transfer delay ..... | 18 | +| | 8.3 Ethernet frame error ratio (FER) ..... | 20 | +| | 8.4 Ethernet frame loss ratio (FLR)..... | 20 | +| | 8.5 Spurious Ethernet frame rate ..... | 22 | +| | 8.6 Frame rate-related parameters ..... | 22 | +| | 8.7 Comparison with objectives (general calculation for all point-to-multipoint parameters)..... | 23 | +| | 8.8 Organization of parameters according to use case ..... | 23 | +| 9 | Ethernet service availability ..... | 23 | +| | 9.1 Severe errored second (SES ETH )..... | 23 | +| | 9.2 Criteria for entry to and exit from unavailable state..... | 24 | +| | 9.3 Ethernet service availability parameters..... | 24 | +| | Annex A – Secondary terminology for assessing delay variation ..... | 25 | +| | A.1 Introduction ..... | 25 | +| | A.2 Definition of IP packet delay variation ..... | 25 | +| | A.3 Definition of inter-frame delay variation (IFDV) for Ethernet frame transfer..... | 25 | +| | A.4 Summarizing IFDV performance ..... | 26 | +| | A.5 Areas for further study..... | 26 | + +| | Page | +|---------------------------------------------------------------------------------------------------------------------------------------|-------------| +| Appendix I – Implications of sampling large groups..... | 27 | +| I.1    Introduction ..... | 27 | +| I.2    Performance at sample destinations ..... | 27 | +| Appendix II – Alternative parameters using the framework of this Recommendation ..... | 28 | +| II.1    Introduction ..... | 28 | +| II.2    Point-to-multipoint performance parameters ..... | 28 | +| II.3    Relationship to other standards ..... | 29 | +| Appendix III – Harmonizing terminology for frame delay and frame delay variation
metrics ..... | 30 | +| III.1    Introduction ..... | 30 | +| III.2    Frame delay and frame delay variation ..... | 30 | +| III.3    Inter-frame delay variation ..... | 31 | +| III.4    Concatenation of inter-frame delay variation..... | 31 | +| Appendix IV – Networking technologies making use of Ethernet ..... | 33 | +| Appendix V – OAM measurement considerations ..... | 34 | +| V.1    Introduction ..... | 34 | +| V.2    Loss performance based on counters..... | 34 | +| Appendix VI – Mapping to Recommendation ITU-T G.8010 terms and conventions (and
to those of other associated Recommendations)..... | 35 | +| VI.1    Introduction ..... | 35 | +| VI.2    Mapping between Ethernet network performance and architecture
Recommendations ..... | 35 | +| VI.3    In-service measurement and applicability of performance and availability
parameters..... | 37 | +| Bibliography..... | 39 | + +# Recommendation ITU-T Y.1563 + +# Ethernet frame transfer and availability performance + +# 1 Scope + +This Recommendation defines parameters that may be used in specifying and assessing the performance of speed, accuracy, dependability and availability of Ethernet frame transfer on an Ethernet network. It provides a simple set of constructs (terms, definitions and illustrations) and the semantics that allow the performance parameters to be applied to Ethernet networks in many useful ways. + +This Recommendation describes Ethernet networks in terms of basic sections, such as networks and links, and measurement points at the boundaries between them. These descriptive terms and concepts have been developed and refined over a series of Recommendations addressing various networking technologies (e.g., ATM, IP, MPLS), and applied to Ethernet technology in this Recommendation. Ethernet networks described using these basic sections (and a few well-known concepts in the networking industry) can be related to Ethernet layer networks defined in [ITU-T G.8010] (architecture of Ethernet layer networks) and Ethernet services defined in [b-ITU-T G.8011]. [ITU-T G.8010] provides a functional specification of Ethernet bridges as defined in [b-IEEE 802.1D] and [b-IEEE 802.1Q]. Appendix VI provides the relationship. + +The defined parameters apply to networks that provide, or contribute to the provision of, Ethernet services in accordance with the normative references specified in clause 2. + +It applies to point-to-point Ethernet topologies and to point-to-multipoint Ethernet topologies. Multipoint-to-multipoint topologies which add a greater level of complexity are left for further study. + +The scope of this Recommendation is summarized in Figure 1. The Ethernet network performance parameters are defined on the basis of Ethernet frame transfer reference events that may be observed at measurement points (MPs) associated with specified functional and jurisdictional boundaries. For comparability and completeness, Ethernet network performance is considered in the context of the $3 \times 3$ performance matrix defined in [b-ITU-T I.350]. Three protocol-independent communication functions are identified in the matrix: access, user information transfer and disengagement. Each function is considered with respect to three general performance concerns (or "performance criteria"): speed, accuracy and dependability. An associated two-state model provides a basis for describing Ethernet network availability. + +Access and disengagement phases are beyond the scope of this Recommendation. In particular, additional Ethernet frames associated to MAC learning procedures are not considered in this Recommendation, since they are related to the access phase. + +![Figure 1 – Scope of this Recommendation. The diagram illustrates the scope of ITU-T Recommendation Y.1563. It shows two network scenarios: a 'Network section' with an 'Ethernet network' containing two 'Bridge' components, and an 'Exchange link' with a 'Link' between 'Bridge or SRC' and 'Bridge or DST'. Both scenarios show 'MP' (Measurement Point) locations and 'Boundary' points where 'ETH frame' transfer occurs. A central box labeled 'Y.1563 – Ethernet frame transfer reference events' (Clause 7) is connected to a table (Clause 8) with columns for 'Criterion' (Speed, Accuracy, Dependability) and 'Function' (Access, User information transfer, Disengagement). The 'User information transfer' row is highlighted with a box labeled 'Y.1563 – Ethernet frame transfer performance parameters'. This box is connected to a box labeled 'Y.1563 – availability parameters', which is further connected to two ovals: 'Ethernet service unavailable' and 'Ethernet service available'. The diagram is labeled 'Y.1563(09)_F01'.](3121ebddccf183ca63bb9781be440a7e_img.jpg) + +MP Measurement point + +**Y.1563 – Ethernet frame transfer reference events** (Clause 7) + +(Clause 8) + +| Function \ Criterion | Speed | Accuracy | Dependability | +|---------------------------|----------------------------------------------------------------|----------|---------------| +| Access | Y.1563 – Ethernet frame transfer performance parameters | | | +| User information transfer | | | | +| Disengagement | | | | + +(Clause 9) + +**Y.1563 – availability parameters** + +Ethernet service unavailable + +Ethernet service available + +Y.1563(09)\_F01 + +Figure 1 – Scope of this Recommendation. The diagram illustrates the scope of ITU-T Recommendation Y.1563. It shows two network scenarios: a 'Network section' with an 'Ethernet network' containing two 'Bridge' components, and an 'Exchange link' with a 'Link' between 'Bridge or SRC' and 'Bridge or DST'. Both scenarios show 'MP' (Measurement Point) locations and 'Boundary' points where 'ETH frame' transfer occurs. A central box labeled 'Y.1563 – Ethernet frame transfer reference events' (Clause 7) is connected to a table (Clause 8) with columns for 'Criterion' (Speed, Accuracy, Dependability) and 'Function' (Access, User information transfer, Disengagement). The 'User information transfer' row is highlighted with a box labeled 'Y.1563 – Ethernet frame transfer performance parameters'. This box is connected to a box labeled 'Y.1563 – availability parameters', which is further connected to two ovals: 'Ethernet service unavailable' and 'Ethernet service available'. The diagram is labeled 'Y.1563(09)\_F01'. + +**Figure 1 – Scope of this Recommendation** + +The objectives associated with the Ethernet user information transfer performance parameters are for further study. Another Recommendation will specify these performance objectives. + +The end-to-end performance of Ethernet networks providing access and disengagement functions and higher-layer transport capabilities (e.g., Internet Protocol) may be addressed in separate Recommendations. + +This Recommendation is structured as follows: Clause 1 specifies its scope. Clause 2 specifies its normative references. Clause 3 lists the terms used and/or defined in this Recommendation. Clause 4 provides a list of abbreviations. Clause 6 illustrates the layered model that creates the context for Ethernet performance specification. Clause 7 defines the model used for Ethernet performance, including network sections and measurement points, reference events and outcomes. Clause 8 uses this model to define Ethernet frame transfer performance parameters. Clause 9 then defines Ethernet service availability parameters. Appendix I describes the implications of sampling large multicast groups on performance parameters definitions and possibly the associated objectives. Appendix II provides alternative parameters which use the framework of point-to-point parameters at registered destinations of a multicast group defined in this Recommendation. Appendix III proposes to harmonize terminologies for frame delay and frame delay variation metrics developed by ITU-T and MEF. Appendix IV describes different networking opportunities making use of Ethernet technology. Finally, Appendix V presents OAM measurement considerations, and Appendix VI addresses the mapping to alternate descriptive terms for Ethernet architectures in [ITU-T G.8010]. + +NOTE 1 – The speed, accuracy and dependability parameters of this Recommendation are intended to characterize Ethernet service in the available state. + +However, no measurements of these parameters made during periods of unavailable time are ever used for determining long-term frame transfer performance, and mechanisms must be established to exclude all performance measurement results collected during unavailable periods from any estimations of long-term Ethernet frame performance parameters. + +NOTE 2 – The parameters of this Recommendation are designed to characterize the performance of service provided by network elements between specified section boundaries. However, users of this Recommendation should be aware that network elements outside the specified boundaries can sometimes influence the measured performance of the elements between the boundaries. + +NOTE 3 – The parameters defined in this Recommendation can also be applied to any subset of the Ethernet frames offered to a given set of network equipment. Methods for aggregating performance over a set of network equipment or over an entire network are outside of the scope of this Recommendation. + +NOTE 4 – The word "provisional", as used in this Recommendation, means that there is agreement on the stability of the value referenced, but that the value may change following further study, or on the basis of real network operational experience. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- | | | +|-----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| [ITU-T G.805] | Recommendation ITU-T G.805 (2000), Generic functional architecture of transport networks . | +| [ITU-T G.809] | Recommendation ITU-T G.809 (2003), Functional architecture of connectionless layer networks . | +| [ITU-T G.8010] | Recommendation ITU-T G.8010/Y.1306 (2004), Architecture of Ethernet layer networks . | +| [IEEE 802.1ad] | IEEE 802.1ad (2005), IEEE Standard for Local and metropolitan area networks – Virtual Bridged Local Area Networks – Amendment 4: Provider Bridges . | +| [IEEE 802.1ag] | IEEE 802.1ag (2007), IEEE Standard for Local and metropolitan area networks – Virtual Bridged Local Area Networks – Amendment 5: Connectivity Fault Management . | +| [IEEE 802.1ah] | IEEE 802.1ah (2008), IEEE Standard for Local and metropolitan area networks – Virtual Bridged Local Area Networks – Amendment 6: Provider Backbone Bridges . | +| [IEEE 802.3] | IEEE 802.3 (2002), IEEE Standard for Information technology – Telecommunications and Information Exchange Between Systems – Local and Metropolitan Area Networks – Specific Requirements – Part 3: Carrier Sense Multiple Access with Collision Detection (CSMA/CD) Access Method and Physical Layer Specifications . | +| [IETF RFC 3393] | IETF RFC 3393 (2002), IP Packet Delay Variation Metric for IP Performance Metrics (IPPM) . | +| [MEF 10.1] | MEF 10.1 (2006), Ethernet Services Attributes Phase 2 . | + +# **3 Definitions** + +## **3.1 Terms defined elsewhere** + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 connection:** [ITU-T G.805]. + +**3.1.2 connection point:** [ITU-T G.805]. + +**3.1.3 Ethernet frame (equivalent to MAC frame):** [IEEE 802.3]. + +**3.1.4 flow:** [ITU-T G.809]. + +**3.1.5 link:** [ITU-T G.805]. + +## **3.2 Terms defined in this Recommendation** + +This Recommendation defines the following terms in clauses 7, 8 and 9: + +**3.2.1 comparative group delivery ratio** + +**3.2.2 comparative group loss ratio** + +**3.2.3 delay variation range over group** + +**3.2.4 frame delay variation** + +**3.2.5 frame error ratio** + +**3.2.6 frame loss ratio** + +**3.2.7 frame reference event** + +**3.2.8 frame transfer delay** + +**3.2.9 global mean transfer delay** + +**3.2.10 group loss ratio** + +**3.2.11 group mean transfer delay** + +**3.2.12 loss ratio range over group** + +**3.2.13 mean Ethernet frame transfer delay** + +**3.2.14 mean transfer delay range over group** + +**3.2.15 median Ethernet frame transfer delay** + +**3.2.16 minimum Ethernet frame transfer delay** + +**3.2.17 maximum Ethernet frame transfer delay** + +**3.2.18 multicast group:** A multicast group is a set of bridges or end points which have been configured to receive frames sent to a given Ethernet multicast address, or which belong to the same VLAN. This set of bridges and their associated egress measurement points provide a key qualification to the point-to-multipoint population of interest. + +**3.2.19 percent Ethernet service availability** + +**3.2.20 percent Ethernet service unavailability** + +**3.2.21 severe errored second** + +**3.2.22 spurious Ethernet frame rate** + +# **4 Abbreviations and acronyms** + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|--------|---------------------------------------------| +| ATM | Asynchronous Transfer Mode | +| CCM | Continuity Check Message | +| CE | Customer Edge | +| DST | Destination customer edge | +| EL | Exchange Link | +| EPL | Ethernet Private Line | +| EPLAN | Ethernet Private Local Area Network | +| ETY | Ethernet physical layer network | +| EVC | Ethernet Virtual Connection | +| EVPL | Ethernet Virtual Private Line | +| EVPLAN | Ethernet Virtual Private Local Area Network | +| FCS | Frame Check Sequence | +| FDV | Frame Delay Variation | +| FER | Frame Error Ratio | +| FLR | Frame Loss Ratio | +| FRE | Frame Reference Event | +| FTD | Frame Transfer Delay | +| GFP | Generic Framing Procedure | +| IFDV | Inter-Frame Delay Variation | +| IPDV | Internet Protocol Packet Delay Variation | +| IP | Internet Protocol | +| IPTV | Internet Protocol Television | +| LAN | Local Area Network | +| LOC | Loss of Continuity | +| MAC | Media Access Control | +| MEG | Maintenance Entity Group | +| MEP | Maintenance End Point | +| MMG | Mismerge (defect) | +| MP | Measurement Point | +| MPLS | MultiProtocol Label Switching | +| NNI | Network-to-Network Interface | +| NS | Network Section | +| NSE | Network Section Ensemble | +| OAM | Operation, Administration and Maintenance | +| OTN | Optical Transport Network | + +| | | +|------------------|----------------------------------------------------------------------------------------| +| PDH | Plesiochronous Digital Hierarchy | +| PE | Provider Edge | +| PEA | Percent Ethernet service Availability | +| PEU | Percent Ethernet service Unavailability | +| $R_{\max}$ | Maximum number of successful frames at all destinations in a group, $\max(R_n)$ | +| $R_n$ | Number of successful frames at destination n, with respect to a population of interest | +| RSTP | Rapid Spanning Tree Protocol | +| S | the number of frames a Source transmits that constitute the population of interest | +| SDH | Synchronous Digital Hierarchy | +| SLS | Service Level Specification | +| SRC | Source Customer edge | +| STP | Spanning Tree Protocol | +| TCP | Transmission Control Protocol | +| $T_{\max}$ | Maximum Ethernet frame delay beyond which the frame is declared to be lost | +| $T_{\text{POI}}$ | Interval of time corresponding to transmission of the Population Of Interest | +| $T_{R,n}$ | Interval corresponding to reception of the population of interest at destination n | +| UNI | User-to-Network Interface | +| VID | Virtual local area network Identifier | +| VLAN | Virtual Local Area Network | + +# 5 Conventions + +None. + +# 6 Layered model of performance for Ethernet service + +Figure 2 illustrates the layered nature of the performance of Ethernet service. The performance provided to Ethernet service users depends on the performance of other layers: + +- Lower layers that provide (via "links") connection-oriented or connectionless transport supporting the Ethernet layer. Links are terminated at points where Ethernet frames are forwarded (i.e., "bridges", "SRC" and "DST") and thus have no end-to-end significance. Links may involve different types of technologies, for example, SDH, OTN, PDH, MPLS, ATM and ETY. +- The Ethernet layer that provides transport of Ethernet frames. The Ethernet layer has end-to-end significance for a given pair of source and destination MAC addresses, possibly within the scope of an Ethernet virtual local area network (VLAN). +- Higher layers, supported by Ethernet, that further enable end-to-end communications. Upper layers may include, for example, IP, MPLS and Ethernet (different networking opportunities using Ethernet in higher layers are described in Appendix IV). The higher layers will modify and may enhance the end-to-end performance compared to that provided at the Ethernet layer (for example, frame loss may result in retransmission and delayed delivery to a higher layer). + +![Figure 2: Layered model of performance for Ethernet service – Example. The diagram shows a layered architecture across three main performance layers: Higher layer performance, Ethernet service performance, and Lower layer performance. The Higher layer performance layer contains a box for 'User information (e.g. data)' which feeds into a box containing '(IP)', '(MPLS)', and 'etc. (Ethernet)'. The Ethernet service performance layer contains four 'Ethernet layer' boxes. The Lower layer performance layer (labeled '3 instances') contains three 'LL' (Link Layer) boxes. The network components at the bottom are SRC, Link, Bridge, Link, Bridge, Link, and DST, connected by arrows. The SRC and DST are connected to the first and last Ethernet layers respectively. The Link and Bridge components are connected to the LL boxes, which in turn connect to the Ethernet layers. The diagram is labeled 'Y.1563' and 'Y.1563(09)_F02'.](af7916c89a458fdab6c3f443217388ae_img.jpg) + +Figure 2: Layered model of performance for Ethernet service – Example. The diagram shows a layered architecture across three main performance layers: Higher layer performance, Ethernet service performance, and Lower layer performance. The Higher layer performance layer contains a box for 'User information (e.g. data)' which feeds into a box containing '(IP)', '(MPLS)', and 'etc. (Ethernet)'. The Ethernet service performance layer contains four 'Ethernet layer' boxes. The Lower layer performance layer (labeled '3 instances') contains three 'LL' (Link Layer) boxes. The network components at the bottom are SRC, Link, Bridge, Link, Bridge, Link, and DST, connected by arrows. The SRC and DST are connected to the first and last Ethernet layers respectively. The Link and Bridge components are connected to the LL boxes, which in turn connect to the Ethernet layers. The diagram is labeled 'Y.1563' and 'Y.1563(09)\_F02'. + +Note – The Ethernet layer is not terminated between the SRC and DST. + +**Figure 2 – Layered model of performance for Ethernet service – Example** + +# 7 Ethernet service performance model, reference events and outcomes + +This clause defines a generic Ethernet service performance model. The model is primarily composed of two types of sections: the exchange link and the network section. These are defined in clause 7.2. They provide the building blocks with which any end-to-end Ethernet service may be represented. Each of the performance parameters defined in this Recommendation can be applied to the unidirectional transfer of Ethernet frames on a section or a concatenated set of sections. + +Clause 7.3 defines the measurement points and measurable sections. Clause 7.4 specifies the set of Ethernet frame transfer reference events that provide the basis for performance parameter definition. These reference events are derived from and are consistent with relevant Ethernet service and protocol definitions. Clause 7.5 then uses those reference events to enumerate the possible outcomes when a frame is delivered into a section. Clause 7.6 defines the populations of interest. + +## 7.1 Network components + +The ETH topological components are defined in [ITU-T G.8010]. + +The following groupings of network components are defined. + +## 7.2 Links and network sections + +### 7.2.1 Exchange link (EL) + +The link connecting: + +- 1) a source or destination CE to its adjacent PE (e.g., bridge) possibly in another jurisdiction, sometimes referred to as an access link, ingress link or egress link; or +- 2) a bridge in one network section with a bridge in another network section. + +Note that the responsibility for an exchange link, its capacity and its performance is typically shared between the connected parties. + +### 7.2.2 Network section (NS) + +A set of bridges together with all of their interconnecting links that together provide a part of the Ethernet service between an SRC and a DST, and are under a single (or collaborative) jurisdictional responsibility. Some network sections consist of a single bridge with no interconnecting links. Source NS and destination NS are particular cases of network sections. Pairs of network sections are connected by exchange links. + +NOTE – "Network section" is roughly equivalent to the term "transport operator network" as defined in [b-ITU-T G.8011]. It is also possible that a transport operator network contains more than one network section. + +Any set of bridges interconnected by links could be considered a network section. However, for the (future) purpose of Ethernet performance allocation, it will be relevant to focus on the set of bridges and links under a single (or collaborative) jurisdictional responsibility. Typically, these bridges belong to the same domain. The destination address, VLAN ID, and the configuration of the Ethernet network (e.g., forwarding rules) dictate the permissible egress port(s) out of this network section (to other NS via exchange links). + +## **7.3 Measurement points and measurable sections** + +This clause defines the key elements of this Recommendation's performance measurement and specification framework. See Appendix VI for additional information on measurement points and measurable sections in the ITU-T G.8010 architecture. + +### **7.3.1 Measurement point (MP)** + +A measurement point is the boundary between a bridge and an adjacent link at which performance reference events can be observed and measured. + +A section or a combination of sections is measurable if it is bounded by a set of MPs. In this Recommendation, the following sections are measurable. + +### **7.3.2 Basic section** + +A basic section is either an EL or a NS. Basic sections are delimited by MPs. + +The performance of any EL or NS is measurable relative to any given Ethernet service. The *ingress MPs* are the set of MPs crossed by frames from that service as they go into that basic section. The *egress MPs* are the set of MPs crossed by frames from that service as they leave that basic section. + +### **7.3.3 End-to-end Ethernet network** + +An end-to-end Ethernet network is the set of EL and NS that provide the transport of Ethernet frames transmitted from SRC to DST. The MPs that bind the end-to-end Ethernet network are the MPs at the SRC and the DST. + +The end-to-end Ethernet network performance is measurable relative to any given Ethernet service. The *ingress MPs* are the MPs crossed by frames from that service as they go into the end-to-end network at the SRC. The *egress MPs* are the MPs crossed by frames from that service as they leave the end-to-end network at the DST. + +### **7.3.4 Network section ensemble (NSE)** + +An NSE refers to any connected subset of NSs together with all of the ELs that interconnect them. The term "NSE" can be used to refer to a single NS, two NSs or any number of NS and their connecting EL. Pairs of distinct NSEs are connected by exchange links. The term "NSE" can also be used to represent the entire end-to-end Ethernet network. NSEs are delimited by MPs. + +The performance of any given NSE is measurable relative to any given unidirectional end-to-end Ethernet service. The *ingress MPs* are the set of MPs crossed by frames from that service as they go into that NSE. The *egress MPs* are the set of MPs crossed by frames from that service as they leave that NSE. + +## **7.4 Ethernet frame transfer reference events (FREs)** + +In the context of this Recommendation, the following definitions apply on a specified point-to-point Ethernet connection or point-to-multipoint Ethernet connection. The defined terms are illustrated in Figure 3. + +![Diagram illustrating Ethernet frame transfer reference events. It shows a sequence of components: 'Bridge or SRC' (containing 'Ethernet layer' and 'Lower layer' with frame A), an 'Exchange link', a 'Bridge' (containing 'Ethernet layer' and 'Lower layer' with frame B), another 'Exchange link', a second 'Bridge' (containing 'Ethernet layer' and 'Lower layer' with frame C), a third 'Exchange link', and finally a 'Bridge or DST' (containing 'Ethernet layer' and 'Lower layer' with frame D). Each bridge is associated with a 'Measurement Point (MP)'. A central oval labeled 'Network section' encompasses the two bridges and the links between them. The diagram is labeled 'Y.1563(09)_F03'.](33ed1f9b27c7c21c797aa928b0f06851_img.jpg) + +Diagram illustrating Ethernet frame transfer reference events. It shows a sequence of components: 'Bridge or SRC' (containing 'Ethernet layer' and 'Lower layer' with frame A), an 'Exchange link', a 'Bridge' (containing 'Ethernet layer' and 'Lower layer' with frame B), another 'Exchange link', a second 'Bridge' (containing 'Ethernet layer' and 'Lower layer' with frame C), a third 'Exchange link', and finally a 'Bridge or DST' (containing 'Ethernet layer' and 'Lower layer' with frame D). Each bridge is associated with a 'Measurement Point (MP)'. A central oval labeled 'Network section' encompasses the two bridges and the links between them. The diagram is labeled 'Y.1563(09)\_F03'. + +NOTE 1 – Ethernet exit events for frames A and C. + NOTE 2 – Ethernet entry events for frames B and D. + +**Figure 3 – Example Ethernet frame transfer reference events** + +An Ethernet frame transfer event occurs when: + +- an Ethernet frame crosses a measurement point (MP); and +- standard Ethernet procedures applied to the frame verify that the FCS is valid; and +- the source and destination address fields within the Ethernet frame header contain the expected MAC addresses. + +Four types of Ethernet frame transfer events are defined below. + +### **7.4.1 Ethernet frame entry event into a CE** + +An Ethernet frame transfer entry event into a bridge occurs when an Ethernet frame crosses an MP entering a bridge (PE or DST) from the attached EL. + +### **7.4.2 Ethernet frame exit event from a CE** + +An Ethernet frame transfer exit event from a bridge occurs when an Ethernet frame crosses an MP exiting a bridge (PE or SRC) into the attached EL. + +### **7.4.3 Ethernet frame ingress event into a basic section or NSE** + +An Ethernet frame transfer ingress into a basic section event occurs when an Ethernet frame crosses an ingress MP into a basic section. + +### **7.4.4 Ethernet frame egress event from a basic section or NSE** + +An Ethernet frame transfer egress event from a basic section occurs when an Ethernet frame crosses an egress MP out of a basic section. + +NOTE 1 – Ethernet frame entry and exit events always represent, respectively, entry into and exit from an end station. Ethernet frame ingress events and egress events always represent ingress into and egress from a section or an NSE. To illustrate this point, note that an ingress into an EL creates an exit event from the preceding bridge, while an ingress into an NS is an entry event because, by definition, NSs always have end stations at their edges. + +NOTE 2 – For practical measurement purposes, Ethernet frame transfer reference events need not be observed within the MAC layer of the end station. Instead, the time of occurrence of these reference events can be approximated by observing the Ethernet frames crossing an associated physical interface. This physical interface should, however, be as near as possible to the desired MP. In cases where reference events are monitored at a physical interface, the time of occurrence of an exit event from an end station is approximated by the observation of the first bit of the Ethernet frame coming from the end station or test equipment. The time of occurrence of an entry event into an end station is approximated by the observation of the last bit of the Ethernet frame going to the end station or test equipment. + +## 7.5 Ethernet frame transfer outcomes + +By considering Ethernet frame transfer reference events associated with a particular source-destination pair, a number of elementary Ethernet frame transfer outcomes may be defined for any frame attempting to cross a basic section or an NSE. A transmitted Ethernet frame is either *successfully transferred*, *errored*, *misdirected*, or *lost*. A delivered Ethernet frame for which no corresponding Ethernet frame was offered is said to be *spurious*. + +Figure 4 illustrates the Ethernet frame transfer outcomes. + +The definitions of Ethernet frame transfer outcomes are based on the concepts of *permissible ingress MP*, *permissible egress MP* and *corresponding frames*. + +![Figure 4: Ethernet frame transfer outcomes. A diagram showing the relationship between Ingress MP and Egress MP for different frame transfer outcomes. It includes boxes for FRE1 and FRE2, time constraints (t ≤ Tmax and t > Tmax), and labels for Successful, Errored, Spurious, and Lost Ethernet frame outcomes.](16152cf1d84aea10848758f51a91ff6a_img.jpg) + +``` + +graph TD + subgraph Ingress_MP [Ingress MP] + I1[FRE1 + $t \leq T_{max}$ ] + I2[FRE1 + $t \leq T_{max}$ ] + I3[FRE1] + I4[FRE1 + $t > T_{max}$ ] + end + + subgraph Egress_MP [Egress MP] + E1[FRE2 +valid header and +error-free payload] + E2[FRE2 +corrupted header or +errored payload] + E3[FRE2 +(Note)] + E4[Never delivered or +delivered to an unpermitted +egress MP] + E5[FRE2 +(Note)] + end + + I1 --> E1 + I2 --> E2 + E3 + I3 --> E4 + I4 --> E5 + + E1 --- S1[Successful +Ethernet frame outcome] + E2 --- S2[Errored +Ethernet frame outcome] + E3 --- S3[Spurious +Ethernet frame outcome] + E4 --- S4[Lost +Ethernet frame outcome] + E5 --- S5[Lost +Ethernet frame outcome] + +``` + +NOTE – Outcome occurs independently of Ethernet frame contents. + +Y.1563(09)\_F04 + +Figure 4: Ethernet frame transfer outcomes. A diagram showing the relationship between Ingress MP and Egress MP for different frame transfer outcomes. It includes boxes for FRE1 and FRE2, time constraints (t ≤ Tmax and t > Tmax), and labels for Successful, Errored, Spurious, and Lost Ethernet frame outcomes. + +**Figure 4 – Ethernet frame transfer outcomes** + +### 7.5.1 Global forwarding information and permissible output links + +In theory, once connectivity has been established in an Ethernet network, a frame can be delivered to any switch, NS or NSE within the network, and still arrive at its destination. However, global forwarding information for an NS may define a restricted set of destination addresses (MAC address, or a combination of MAC address and VLAN ID) that each network is willing and able to serve on behalf of each of its adjoining NSs. The global forwarding information for an NS is the consolidation of all the local bridging information in that NS. It is reasonable to assume that (in the worst case) an NS will completely discard any frames with destination MAC addresses for which that NS is unable or not configured to serve. Therefore, all Ethernet frames leaving a basic section should only be forwarded to other basic sections as *permitted* by the available global forwarding information. + +For performance purposes, the transport of an Ethernet frame by an Ethernet network will be considered successful only when that Ethernet network forwards all of the frame contents to other basic sections as permitted by the currently available global forwarding information. If the + +destination MAC address corresponds to a CE attached directly to this NSE, the only permitted output and the only successful Ethernet forwarding is to the destination CE. + +Address learning procedures allow Ethernet switches to learn the MAC addresses of unknown bridges in order to identify on which port the traffic should be sent and establish connectivity. This operation may be considered as part of the access phase of the communication, and as such only the output links (or egress MP) identified in the bridge table for a given end-to-end Ethernet service will be considered permissible. + +NOTE – Ethernet procedures and protocols (STP, RSTP) include updating of global forwarding information. An NS that was permissible may no longer be permissible following an update of the forwarding information shared between NSs, and this may include information from other networking technologies that support the Ethernet network. Alternatively, a NS that was not previously permissible may have become permissible after an update of the global forwarding information. The notion of permissible basic sections should be studied further in the context of Ethernet networks. + +At a given time, and relative to a given end-to-end Ethernet service and a basic section or NSE: + +- an ingress MP is a *permissible ingress MP* if the crossing of this MP into this basic section or NSE is permitted by the global forwarding information; +- an egress MP is a *permissible egress MP* if the crossing of this MP leads into another basic section that is permitted by the global forwarding information. + +### 7.5.2 Corresponding events + +Performance analysis makes it necessary to associate the frames crossing one MP with the frames that crossed a different MP. A frame should leave a basic section on more than one permissible egress MP when the section performs replication in a point-to-multipoint case or when flooding during MAC learning. Successive frames (intended for a given destination) may use a different egress MP over time due to network topology changes. + +An Ethernet egress event is said to *correspond* to an earlier ingress event if they were created by the "same" Ethernet frame. In the point-to-multipoint case, several egress events usually *correspond* to a single ingress event (e.g., MAC learning frames, broadcast frames). + +The practical determination of whether Ethernet reference events are corresponding is usually ad hoc and will often rely on consideration of the MAC addresses, VLAN identifiers, the global bridging information, other header information and the Ethernet frame contents. + +When maintenance end points (MEPs) are used ([b-ITU-T Y.1731], [IEEE 802.1ag]), accurate frame counting requires access to information about the MEP that corresponds with the source address, and this information can come from provider bridge [IEEE 802.1ad] and provider backbone bridge [IEEE 802.1ah] encapsulations. In the absence of this information, customer MAC addresses need to be maintained in MEPs possibly with a large overhead. + +### 7.5.3 Successful Ethernet frame transfer outcome + +A successful frame transfer outcome occurs when a single Ethernet frame reference event at a permissible ingress MP0 results in one (or more) corresponding reference event(s) at one (or more) egress MPi, all within a specified time Tmax of the original ingress event and: + +- 1) all egress MPi where the corresponding reference events occur are permissible; and +- 2) the complete contents of the original frame observed at MP0 are included in the delivered frame(s); and +- 3) the binary contents of the delivered Ethernet frame information field(s) conform exactly with that of the original frame; and +- 4) the header field(s) of the delivered frame(s) is (are) valid. + +NOTE – The value of Tmax is for further study. + +### 7.5.4 Errored Ethernet frame outcome + +An errored frame outcome occurs when a single Ethernet frame reference event at a permissible ingress $MP_0$ results in one (or more) corresponding reference event(s) at one (or more) egress $MP_i$ , all within $T_{max}$ time of the original reference event and: + +- 1) all egress $MP_i$ where the corresponding reference events occur are permissible; and +- 2) the complete contents of the original frame observed at $MP_0$ are included in the delivered frame(s); and +- 3) either: + - the binary contents of the delivered Ethernet frame information field(s) do not conform exactly with that of the original frame; or + - one or more of the header field(s) of the delivered frame(s) is (are) corrupted. + +NOTE – Most frames with errored headers that are not detected by the FCS at the Ethernet layer will be discarded. The result is that no reference event is created for the higher layer protocols expecting to receive this frame. Because there is no Ethernet reference event, these frame transfer attempts will be classified as lost frame outcomes. Errored headers that do not result in discarding or misdirecting will be classified as errored frame outcomes. + +### 7.5.5 Lost Ethernet frame outcome + +A lost frame outcome occurs when there is a single Ethernet frame reference event at a permissible ingress $MP_0$ , and when some or all of the contents corresponding to that ingress frame do not result in an Ethernet reference event at a permissible egress $MP_i$ within the time $T_{max}$ . + +A lost Ethernet frame outcome may in fact be one or more *misdirected frame* outcomes (which were not observed), as defined below. + +A misdirected frame occurs when a single Ethernet frame reference event at a permissible ingress $MP_0$ results in one (or more) corresponding reference event(s) at one (or more) egress $MP_i$ , all within a specified $T_{max}$ time of the original reference event and: + +- 1) the complete contents of the original frame observed at $MP_0$ are included in the delivered frame(s); but +- 2) one or more of the egress $MP_i$ where the corresponding reference events occur are not permissible egress $MP(s)$ . + +### 7.5.6 Spurious Ethernet frame outcome + +A spurious Ethernet frame outcome occurs for a basic section, or on an end-to-end path, when a single Ethernet frame creates an egress event for which there was no corresponding ingress event. + +A spurious Ethernet frame may have diverse origins. As an example, it may result from bit errors modifying the Ethernet frame MAC destination address, but not detected by the FCS. + +NOTE – Alternatively, the cause could be an error in a forwarding table. In this case, this should go in the misdelivered outcome. + +### 7.5.7 Secondary Ethernet frame outcomes + +The following outcomes are based on the fundamental outcomes described above. + +#### 7.5.7.1 In-order and reordered Ethernet frame outcomes + +The definition of these Ethernet frame outcomes requires some background discussion. + +In-order frame delivery is a property of successful frame transfer attempts, where the sending frame order is preserved on arrival at the destination (or measurement point). Arrival order is determined by position relative to other frames of interest, though the extent to which a given frame has been reordered may be quantified in the units of position, time and payload byte distances. A reordered + +frame performance parameter is relevant for most applications, especially when assessing network support for real-time media streams, owing to their finite ability to restore order or the performance implications a lack of that capability. Frames usually contain some unique identifier applied at the SRC, sometimes assumed to be a sequence number, so this number or other information (such as time stamps from the MP0) is the reference for the original order at the source. The evaluation of arrival order also requires the ability to determine which specific frame is the "next expected" frame, and this is greatly simplified sequence numbers that are consecutive increasing integers. + +An in-order frame outcome occurs when a single Ethernet frame reference event at a permissible egress measurement point results in the following: + +- The frame has a sequence number greater than or equal to the next expected frame value. The next expected value increases to reflect the arrival of this frame, setting a new value of expectation. + +A reordered or out-of-order frame outcome occurs when a single Ethernet frame reference event at a permissible egress measurement point results in the following: + +- The frame has a sequence number lower than the next expected frame value, and therefore the frame is reordered. The next expected value does not change due to arrival of this frame. + +#### **7.5.7.2 Duplicate Ethernet frame outcome** + +A duplicate Ethernet frame outcome is a subset of successful frame outcomes, and occurs when a single Ethernet frame reference event at a permissible ingress MP0 results in two or more corresponding reference event(s) on at least one permissible egress MPi, and the binary information fields of all the output frames are identical to the original frame. The egress reference event at MPi for a duplicate frame occurs subsequently to at least one other corresponding egress reference event for the original frame (usually also at MPi). + +Note that in point-to-point communication, there is only one permissible egress MPi where the destination is directly attached to the NSE. In point-to-multipoint communication, there may be many permissible egress MPi for the various destinations. + +#### **7.5.7.3 Replicated Ethernet frame outcome** + +A replicated frame transfer outcome occurs when a single Ethernet frame reference event at a permissible ingress MP0 results in two or more corresponding reference event(s) on at least one permissible egress MPi, and the binary information fields of all the output frames are identical to the original frame. The egress reference event at MPi for a replicated frame is the first for the original frame and occurs prior to at least one other egress reference event for a duplicate frame (usually also at MPi). + +## **7.6 Frame qualifications** + +Most of the performance parameters are defined over sets of frames called *populations of interest*. + +Descriptions of the population of interest must include: + +- 1) The interval of time from the first to the last ingress reference events (at the source MP and destination MP), TPOI. The corresponding time interval at a particular egress MP n is TR,n. +- 2) The number of frames in the population (all such frames must correspond to ingress reference events). +- 3) The set of permissible ingress and egress MPs during TPOI. +- 4) Other qualifying aspects from the frame header, such as the source and group MAC addresses, etc. + +### 7.6.1 Population of interest for the point-to point case + +For the *end-to-end case*, the population of interest is usually the total set of frames being sent from SRC to DST, over a VLAN where appropriate. The measurement points in the end-to-end case are the MP at the SRC and DST. + +For a basic section or NSE and relative to a particular SRC and DST pair, the population of interest at a particular permissible ingress MP is that set of frames being sent from SRC to DST that are forwarded into the basic section or NSE across that specific MP. This is called the *specific-ingress case*. + +The total population of interest for a basic section or NSE relative to a particular SRC and DST pair is the total set of frames from SRC to DST that are delivered into the section or NSE across any of its permissible ingress MP. This is called the *ingress-independent case*. + +### 7.6.2 Ethernet frame flow + +An Ethernet frame flow is the set of frames associated with a given connection or connectionless stream having the same source MAC address (SRC), the same destination MAC address (DST) in case of point-to-point connections or the same set of destinations in case of point-to-multipoint connections, the same Ethernet VLAN tag, or the same session identification (e.g., IP addresses or port numbers from a higher-layer protocol). The VLAN tag includes both a VLAN ID and the user priority bits, commonly referred to as the p-bits. + +An Ethernet frame flow is the most common example of a population of interest. Some in-service measurements (or monitoring) may be conducted on the aggregate of many frame flows for practical reasons. + +### 7.6.3 Population of interest for the point-to-multipoint case + +For the *point-to-multipoint case*, the population of interest is usually the total set of frames being sent from source to a set of destinations that are members of a specific multipoint VLAN (a VLAN with two or more permissible egress MP). The measurement points in the typical NSE "end-to-end" case are the MPs at the source and destinations. + +It is important to note that the set of permissible ingress and egress MPs may change during $T_{POI}$ . In some forms of point-to-multipoint communication, the source transmits to the multicast group continuously, and destinations may join or leave the group whenever they wish (this would correspond to a user viewing the live television channels offered in an IPTV system). A destination's group membership activity determines the portion of the population of interest that is relevant to the calculation of its point-to-point parameters. + +Thus, when a source has transmitted $S$ frames during $T_{POI}$ , and a specific destination $n$ joins the group while $T_{POI}$ is in progress, then the number of frames relevant to calculating that destination's point-to-point parameters is $S_n$ . The first frame considered to count toward $S_n$ is the first frame observed that is part of a particular multicast group. If a destination leaves the group during $T_{POI}$ , then the last frame considered to count toward $S_n$ is the last frame observed that is part of a particular multicast group. Likewise, the number of frames successfully delivered to a particular destination is $R_n$ . + +A set of $n$ destinations is designated by $D = \{D_1, D_2, D_3, D_4, D_5, \dots, D_n\}$ , registered for the multicast group included in the population of interest. + +# 8 Ethernet frame transfer performance parameters + +This clause defines a set of Ethernet frame information transfer performance parameters using the Ethernet frame transfer outcomes defined in clause 7.5. All of the parameters may be estimated on the basis of observations made at MP that bound the basic section or NSE under test. + +The performance parameters in packet networks are usually defined in terms of packet loss and packet delay. Ethernet services are no different and their performance can be identified based on frame transfer delay and frame loss. Performance parameters are useful for monitoring the quality of a connection and are usually a part of the overall network management and OAM. The performance of point-to-multipoint frame distribution to a set of destinations can be considered a set of point-to-point frame transfers, and characterized using any or all of the point-to-point parameters. Parameters that are specific to the point-to-multipoint case are also defined below. + +The names of the point-to-multipoint parameters employ two adjectives with the following meanings: + +- **Global**: equal weighting given to all *frames* in the population of interest. +- **Group**: equal weighting given to the point-to-point parameters calculated for each *destination* that is member of the group. + +Both types of parameters take the possibility of group membership changes into account. + +Some parameters can be taken as more primary than others. For example, a global frame loss ratio result of zero indicates that all frames have been delivered to all destinations, and there is no need to investigate any per-destination point-to-point results for that population of interest. + +## 8.1 Point-to-point Ethernet frame transfer delay (FTD) + +Point-to-point frame transfer delay is the time required to transfer a frame from its source to its intended destination. Using round-trip delays may be worthwhile inclusions in this Recommendation because of their simplicity. These inclusions are for further study. + +Ethernet frame transfer delay is defined for all successful and errored frames outcomes across a transport operator network. FTD is the time, $(t_2 - t_1)$ between the occurrence of two corresponding Ethernet frame reference events, ingress event FRE1 at time $t_1$ and egress event FRE2 at time $t_2$ , where $(t_2 > t_1)$ and $(t_2 - t_1) \leq T_{\max}$ . The end-to-end Ethernet frame transfer delay is the one-way delay between the MP at the SRC and DST as illustrated in Figure 5. + +![Figure 5: Ethernet frame transfer delay events. The diagram illustrates the path of an Ethernet frame from a Source (SRC) to a Destination (DST) through a series of Multipoint (MP) nodes. The path starts at SRC (MP1) and ends at DST (MPn). The frame enters the network at SRC (Ingress event FRE1 at time t1) and exits at DST (Egress event FRE2 at time t2). The path is divided into segments by nodes MP2, MP3, MP4, MP5, MPn-2, and MPn-1. Each segment is labeled with 'EL' (Ethernet Link) or 'NS' (Network Segment). The diagram shows the frame's entry and exit at each node, with the total delay being the time between the ingress event at SRC and the egress event at DST.](75e4b78ee25f885d73120e3066a5253e_img.jpg) + +Y.1563(09)\_F05 + +Figure 5: Ethernet frame transfer delay events. The diagram illustrates the path of an Ethernet frame from a Source (SRC) to a Destination (DST) through a series of Multipoint (MP) nodes. The path starts at SRC (MP1) and ends at DST (MPn). The frame enters the network at SRC (Ingress event FRE1 at time t1) and exits at DST (Egress event FRE2 at time t2). The path is divided into segments by nodes MP2, MP3, MP4, MP5, MPn-2, and MPn-1. Each segment is labeled with 'EL' (Ethernet Link) or 'NS' (Network Segment). The diagram shows the frame's entry and exit at each node, with the total delay being the time between the ingress event at SRC and the egress event at DST. + +**Figure 5 – Ethernet frame transfer delay events** +(illustrated for the end-to-end transfer of a single Ethernet frame) + +Due to the nodal queuing delay, frame transfer delay is a random quantity that is usually characterized by its mean and variations. + +### **8.1.1 Mean Ethernet frame transfer delay** + +Mean Ethernet frame transfer delay is the arithmetic average of Ethernet frame transfer delays for a population of interest. + +### **8.1.2 Minimum Ethernet frame transfer delay** + +Minimum Ethernet frame transfer delay is the smallest value of Ethernet frame transfer delay among all Ethernet frame transfer delays of a population of interest. This includes propagation delay and queuing delays common to all frames. Therefore, this parameter may not represent the theoretical minimum delay of the path between MPs. + +### **8.1.3 Maximum Ethernet frame transfer delay** + +Maximum Ethernet frame transfer delay is the largest value of Ethernet frame transfer delay among all Ethernet frame transfer delays of a population of interest. + +### **8.1.4 Median Ethernet frame transfer delay** + +The median Ethernet frame transfer delay is the 50th percentile of the frequency distribution of Ethernet frame transfer delays from a population of interest. The median is the middle value once the transfer delays have been rank-ordered. To obtain this value if the population contains an even number of values, the mean of the two central values will be used. + +### **8.1.5 End-to-end 2-point Ethernet frame delay variation** + +The variations in Ethernet frame transfer delay are also important. Streaming applications might use information about the total range of Ethernet frame delay variation to avoid buffer underflow and overflow. Extreme variations in Ethernet frame delay will cause TCP retransmission timer thresholds to grow and may also cause frame retransmissions to be delayed or cause frames to be retransmitted unnecessarily. + +End-to-end 2-point Ethernet frame delay variation is defined based on the observations of corresponding Ethernet frame arrivals at ingress and egress MP (e.g., $MP_{DST}$ , $MP_{SRC}$ ). These observations characterize the variability in the pattern of Ethernet frame arrival events at the egress MP and the pattern of corresponding events at the ingress MP with respect to a reference delay. + +The 2-point frame delay variation ( $v_k$ ) for an Ethernet frame $k$ between SRC and DST is the difference between the absolute Ethernet frame transfer delay ( $x_k$ ) of frame $k$ and a defined reference Ethernet frame transfer delay, $d_{1,2}$ , between those same MPs (see Figure 6): $v_k = x_k - d_{1,2}$ . + +![Figure 6: 2-point Ethernet frame delay variation. The diagram illustrates frames 0 through k being transmitted from a source through two measurement points, MP1 and MP2. Vertical lines represent the measurement points. Horizontal arrows represent frames. Vertical arrows indicate arrival times: a1,1, a1,2, ..., a1,k at MP1 and a2,0, a2,1, a2,2, ..., a2,k at MP2. A dashed line at the top indicates t=0. A box contains the equations: x_k = a_{2,k} - a_{1,k} and v_k = x_k - d_{1,2}. A separate small diagram on the right shows the relationship between d_{1,2}, v_k, and x_k on a timeline.](c914f51f4427bc672dd0526cfc90ebe9_img.jpg) + +Variables: + +- $a_{1,k}$ Frame $k$ actual arrival time at $MP_1$ . +- $a_{2,k}$ Frame $k$ actual arrival time at $MP_2$ . +- $d_{1,2}$ Absolute ref. frame transfer delay between $MP_1$ and $MP_2$ . +- $x_k$ Absolute frame $k$ transfer time between $MP_1$ and $MP_2$ . +- $v_k$ 2-point frame delay variation value between $MP_1$ and $MP_2$ . + +Y.1563(09)\_F06 + +Figure 6: 2-point Ethernet frame delay variation. The diagram illustrates frames 0 through k being transmitted from a source through two measurement points, MP1 and MP2. Vertical lines represent the measurement points. Horizontal arrows represent frames. Vertical arrows indicate arrival times: a1,1, a1,2, ..., a1,k at MP1 and a2,0, a2,1, a2,2, ..., a2,k at MP2. A dashed line at the top indicates t=0. A box contains the equations: x\_k = a\_{2,k} - a\_{1,k} and v\_k = x\_k - d\_{1,2}. A separate small diagram on the right shows the relationship between d\_{1,2}, v\_k, and x\_k on a timeline. + +**Figure 6 – 2-point Ethernet frame delay variation** + +The reference Ethernet frame transfer delay, $d_{1,2}$ , is the absolute Ethernet frame transfer delay experienced by a selected Ethernet frame between $MP_1$ and $MP_2$ . + +Positive values of 2-point FDV correspond to Ethernet frame transfer delays greater than those experienced by the reference Ethernet frame; negative values of 2-point FDV correspond to Ethernet frame transfer delays less than those experienced by the reference Ethernet frame. The distribution of 2-point FDVs is identical to the distribution of absolute Ethernet frame transfer delays displaced by a constant value equal to $d_{1,2}$ . + +This Recommendation terminology for frame delay and frame delay variation differs somewhat from the terminology used presently by the Metro Ethernet Forum. Appendix III provides the mapping between similar metrics developed by these two standards bodies. + +#### 8.1.5.1 Using minimum delay as the basis for delay variation + +As illustrated in Figure 6, the delay variation of an individual frame is naturally defined as the difference between the actual delay experienced by that frame and a nominal or reference delay. The preferred reference is the minimum delay of the population of interest. This ensures that all variations will be reported as positive values, and simplifies reporting the range of variation (the maximum value of variation is equal to the range). + +There is an alternative to using the minimum frame delay as the nominal delay: to use the average delay of the population of interest as the nominal or reference delay. This has the effect of centring the distribution of delay variation values on zero (when the distribution is symmetrical), and produces both positive and negative variations. However, the average delay of the population may not match the delay of any individual frame, creating an inappropriate reference for variation (e.g., when a bimodal distribution is present). + +#### 8.1.5.2 Quantile-based limits on Ethernet frame delay variation + +The preferred method for summarizing the delay variation of a population of interest is to select upper and lower quantiles of the delay variation distribution and then measure the distance between those quantiles. For example, select the $1-10^{-3}$ quantile and the 0 quantile (or minimum), make measurements, and observe the difference between the delay variation values at these two quantiles. + +This example would help application designers determine the de-jitter buffer size for no more than 0.1% total buffer overflow. + +An objective for Ethernet frame delay variation could be established by choosing an upper bound for the difference between pre-specified quantiles of the delay variation distribution. For example, "the difference between the 99.9 quantile and the minimum of the frame delay variation should be no more than 50 ms." + +#### 8.1.5.3 Interval-based limits on Ethernet frame delay variation + +An alternative method for summarizing the Ethernet frame delay variation experienced by a population of interest is to pre-specify a delay variation interval, e.g., 50 ms, and then observe the percentage of individual frame delay, variations that fall inside and outside of that interval. If the 50 ms interval were used, applications with fixed buffer sizes of at or near 50 ms would then know approximately how many frames would cause buffer overflow or underflow. + +NOTE – If this method is used for summarizing Ethernet frame delay variation, the delay variant of individual frames should be calculated using the minimum delay as nominal in clause 8.1.5.1., instead of the definition of clause 8.1.5 using the first frame. Using the definition of clause 8.1.5, the pre-selected interval (e.g., the 50 ms) might occasionally be anchored on an unusually large or small value. + +An objective for Ethernet frame delay variation could be established by choosing a lower bound for the percentage of individual frame delay variations that fall within a pre-specified interval. For example, "≥99.9% of frame delay variations should be within the interval [0 ms, 50 ms]." + +#### 8.1.5.4 Secondary parameters for Ethernet frame delay variation + +Annex A gives secondary methods for assessing delay variation. Some aspects of these definitions and guidance on their use is for further study. + +## 8.2 Point-to-multipoint Ethernet frame transfer delay + +For the *point-to-multipoint case*, the population of interest (usually the total set of frames that have been sent from the source to a set of destinations that have registered as members of a specific multicast group) forms the matrix displaying frame transfer delays as illustrated in Figure 7. The measurement points in the typical NSE case are the MP at the source and destinations. + +![Diagram illustrating point-to-multipoint terms. It shows a source (SRC) connected to a network of bridges (Br) and destinations (D1, D2, D3, ..., DN). The ingress time is FRE1 at t1, and the egress time is FRE2 at t2. The difference (t2 - t1) is the Frame Transfer Delay (FTD). A matrix of FTD values is shown, with a group vector for each destination. The matrix is labeled 'Matrix (space and time)'.](d3b5eac55166fc428a223bba5c46961b_img.jpg) + +The diagram illustrates the point-to-multipoint Ethernet frame transfer delay. On the left, a source (SRC) is connected to a network of bridges (Br) and destinations (D1, D2, D3, ..., DN). The ingress time is FRE1 at t1, and the egress time is FRE2 at t2. The difference (t2 - t1) is the Frame Transfer Delay (FTD). A matrix of FTD values is shown, with a group vector for each destination. The matrix is labeled 'Matrix (space and time)'. + +| Single value | Results from point-to-point population of interest | | | +|--------------------|----------------------------------------------------|--------------------|--| +| FTD 1,1 | FTD 1,2 | FTD 1,3 | | +| FTD 2,1 | FTD 2,2 | FTD 2,3 | | +| FTD 3,1 | FTD 3,2 | FTD 3,3 | | +| FTD N,1 | FTD N,2 | FTD N,3 | | +| Group vector | | | | + +Matrix (space and time) + +Diagram illustrating point-to-multipoint terms. It shows a source (SRC) connected to a network of bridges (Br) and destinations (D1, D2, D3, ..., DN). The ingress time is FRE1 at t1, and the egress time is FRE2 at t2. The difference (t2 - t1) is the Frame Transfer Delay (FTD). A matrix of FTD values is shown, with a group vector for each destination. The matrix is labeled 'Matrix (space and time)'. + +Figure 7 – Illustration of point-to-multipoint terms + +In addition to $S_n$ and $R_n$ , which are defined in clause 7.6.3, the other point-to-point outcomes can be represented in a similar way. Lost frame outcomes for destination $n$ are counted as $L_n$ , errored frame outcomes are $E_n$ , spurious frame outcomes as $F_n$ , and so forth. Thus, for each point-to-multipoint population of interest, there are sets of counts as follows: + +$$\bar{S} = \{S_1, S_2, \dots, S_N\} \quad \bar{R} = \{R_1, R_2, \dots, R_N\} \quad \bar{L} = \{L_1, L_2, \dots, L_N\}$$ + +and sets of point-to-point parameters, such as: + +$$\overline{FLR} = \{FLR_1, FLR_2, \dots, FLR_N\} \quad \overline{FDV} = \{FDV_1, FDV_2, \dots, FDV_N\}$$ + +where the indices are for destinations (these are vectors of point-to-point parameter results). + +On the other hand, the set of permissible MPs for an NS may be revised due to forwarding adaptation to equipment failures during $T_{POI}$ . This category of changes to the permissible set is expected to be infrequent. + +| | | Point-to-point
populations of interest | | | | Point-to-point parameter
(mean FTD) | Group parameter
(group mean FTD) | +|----------------------------------------------------------------------------------------------------------------------|--------------------|-------------------------------------------|--------------------|------------------------|-----------------------------|----------------------------------------|-------------------------------------| +| triangle
D 1 | FTD 1,1 | FTD 1,2 | FTD 1,3 | ...FTD 1,R1 | $R_1^{-1} \sum_r FTD_{1,x}$ | | | +| triangle
D 2 | FTD 2,1 | FTD 2,2 | FTD 2,3 | ...FTD 2,R2 | $R_2^{-1} \sum_r FTD_{2,x}$ | $N^{-1} \sum_n \text{mean FTD}_n$ | | +| triangle
D 3 | FTD 3,1 | FTD 3,2 | FTD 3,3 | ...FTD 3,R3 | $R_3^{-1} \sum_r FTD_{3,x}$ | | | +| triangle
D N | FTD N,1 | FTD N,2 | FTD N,3 | ...FTD N,RN | $R_N^{-1} \sum_r FTD_{N,x}$ | | | + +Y.1563(09)\_F08 + +NOTE – $R_N$ is the number of received frames at destination $D_N$ . + +**Figure 8 – Illustration of a point-to-multipoint group parameter calculation** + +Note that with group parameters, *any* statistic can be applied to the point-to-point populations of interest, and then *any* statistic can be applied to the point-to-point parameters, not just the mean as illustrated in Figure 8. With global parameters, *any* statistic can be applied to the complete matrix of point-to-point results. Appendix II discusses the possibilities in more detail. + +### 8.2.1 Global mean transfer delay + +The overall mean frame transfer delay for all individual destinations, calculated as the sum of frame transfer delays for all successful Ethernet frame transfer outcomes divided by the total successful Ethernet frame transfer outcomes at all individual destinations. + +Using the concepts and symbols introduced above, the mathematical representation of this parameter is: + +$$\frac{\sum_{n,r}^{N,R_n} FTD_{n,r}}{\sum_{n=1}^N R_n}$$ + +### 8.2.2 Group mean transfer delay + +The overall mean frame transfer delay for all individual destinations, calculated as the sum of point-to-point mean frame transfer delays for all destinations divided by the number of individual destinations (N). This parameter is illustrated in Figure 8. + +The mathematical representation of this parameter is: + +$$\frac{\sum_{n=1}^N \text{mean}(FTD_n)}{N} \quad \text{where } \text{mean}(FTD_n) = R_n^{-1} \sum_r^{R_n} FTD_{n,r}$$ + +### 8.2.3 Mean transfer delay range over group + +This range is determined from the minimum and maximum values of the point-to-point mean frame transfer delays for the set of destinations in the group and a population of interest. Both the minimum and the maximum are recorded, and the range is the difference between the maximum and the minimum. + +The mathematical representation of this parameter is: + +$$\max(\overline{\text{mean}(FTD)}), \min(\overline{\text{mean}(FTD)})$$ + +### 8.2.4 End-to-end 2-point delay variation range over group + +This range is determined from the minimum and maximum values of the point-to-point Ethernet frame delay variation for the set of destinations in the group and a population of interest, where the delay variation is usually expressed as the 1-10-3 quantile of one-way delay minus the minimum one-way delay. If a more demanding service is considered, one alternative is to use the 1-10-5 quantile and, in either case, the quantile used should be recorded with the results. Both the minimum and the maximum are recorded, and both values are given to indicate the range. + +The mathematical representation of this parameter is: + +$$\max(\overline{FDV}), \min(\overline{FDV})$$ + +## 8.3 Ethernet frame error ratio (FER) + +Ethernet frame error ratio is the ratio of total errored Ethernet frame outcomes to the total of successful Ethernet frame transfer outcomes plus errored Ethernet frame outcomes in a population of interest. + +## 8.4 Ethernet frame loss ratio (FLR) + +### 8.4.1 Ethernet frame loss ratio + +The ratio of total lost Ethernet frame outcomes to total transmitted Ethernet frames in a population of interest. + +In point-to-multipoint configurations, it can also be useful to compare the successful frame transfers among destinations using the destination with the largest number of successful frame transfers as the reference. + +### 8.4.2 Global loss ratio + +The overall loss ratio for all individual destinations and a frame population of interest, calculated as the sum of all lost frame outcomes divided by the sum of frames transmitted to each destination while a member of the specified group. + +Using the concepts and symbols introduced above, the mathematical representation of this parameter is: + +$$\frac{\sum_{n=1}^N L_n}{\sum_{n=1}^N S_n}$$ + +### 8.4.3 Mean group loss ratio + +The mean group loss ratio for all registered destinations and a frame population of interest is calculated as the sum of all point-to-point Ethernet frame loss ratios (FLRs) divided by the number of registered destinations that were members of the specified group during $T_{POI}$ . + +The mathematical representation of this parameter is: + +$$\frac{\sum_{n=1}^N FLR_n}{N} \text{ where } FLR_n = \frac{L_n}{S_n}$$ + +### 8.4.4 Loss ratio range over group + +The loss ratio range is determined from the minimum and maximum values of the point-to-point Ethernet frame loss ratios for the set of destinations in the group and a population of interest. Both the maximum and the minimum are recorded, and both values are given to indicate the range. + +The mathematical representation of this parameter is: + +$$\max(\overline{FLR}), \min(\overline{FLR})$$ + +This parameter may be based on a low percentile and a high percentile, such as 1% and 99% or other values, rather than minimum and maximum, because these cannot be known with certainty when sub-sampling the population. In any case, the basis of the range must be included with the results. See Appendix I for further discussion. + +### 8.4.5 Comparative group delivery ratio + +The ratio between the number of successful Ethernet frame transfer outcomes $R_n$ , for a particular individual destination $D_n$ , and the largest number of successful Ethernet frame transfer outcomes at another individual destination, designated $R_{\max}$ , for the population of interest, where both destinations were registered group members throughout $T_{POI}$ . The mathematical representation of this parameter is: + +$$R_n / R_{\max}$$ + +Note that the use of $R_{\max}$ enables a destination-only assessment, but $R_{\max}$ may not equal the transmitted frame count, $S$ for the population of interest. Also, note that the one's-complement of this parameter would be the comparative group loss ratio + +## 8.5 Spurious Ethernet frame rate + +Spurious Ethernet frame rate at an egress MP is the total number of spurious Ethernet frames observed at that egress MP during a specified time interval divided by the time interval duration (equivalently, the number of spurious Ethernet frame per service-second)1. + +## 8.6 Frame rate-related parameters + +Two types of rate-related parameters may currently be defined. One type of parameter measures the rate in terms of the rate of successfully transmitted Ethernet frames; another type of parameter is octet-based and measures the rate in terms of the octets that have been transmitted in those frames. + +**Point-to-point Ethernet frame rate (FR):** For a given population of interest, the Ethernet frame rate at an egress MP is the total number of Ethernet frame transfer reference events observed at that egress MP during a specified time interval divided by the time interval duration, $T_R$ (equivalently, the number of Ethernet frame transfer reference events per service-second). + +Accounting for the possibility that destinations may join or leave a group during $T_{POI}$ , the mathematical representation of this parameter is: + +$$R_n / T_{R,n}$$ + +where $T_{R,n}$ is the time interval corresponding to reception of the population of interest at destination n. + +**Point-to-point octet-based Ethernet frame rate (FOR):** For a given population of interest, the octet-based Ethernet frame rate at an egress MP is the total number of octets transmitted in **Ethernet frame payloads and headers** (including FCS) that result in an Ethernet frame transfer reference event at that egress MP during a specified time interval divided by the time interval duration, $T_{POI}$ (equivalently, the number of octets in the Ethernet frames resulting in Ethernet frame reference events per service-second). + +**Group mean Ethernet frame rate:** The overall mean Ethernet frame rate for all registered destinations, calculated as the sum of FR for all destinations divided by the number of registered destinations (N). + +**Group mean octet-based Ethernet frame rate:** The overall mean Ethernet frame rate for all registered destinations, calculated as the sum of FOR for all destinations divided by the number of registered destinations (N). + +The mathematical representation of these parameters is: + +$$mean(\overline{FR}) = \frac{\sum_{n=1}^N (FR_n)}{N} \quad \text{and} \quad mean(\overline{FOR}) = \frac{\sum_{n=1}^N (FOR_n)}{N}$$ + +**One-way Ethernet frame rate range over group:** This range is determined from the minimum and maximum values of the point-to-point mean one-way Ethernet frame rate for the set of Destinations in the group and a population of interest. Both the minimum and the maximum are recorded, and the range is the difference between the maximum and the minimum. + +The mathematical representation of this parameter is: + +$$\max(\overline{FR}), \min(\overline{FR})$$ + +--- + +1 Since the mechanisms that cause spurious Ethernet frames are expected to have little to do with the number of Ethernet frames transmitted across the sections under test, this performance parameter is not expressed as a ratio, only as a rate. + +(and similar for octet-based rate). + +## 8.7 Comparison with objectives (general calculation for all point-to-multipoint parameters) + +Typically, the users of performance parameters need to make comparisons with objectives. This clause treats the point-to-multipoint parameters as a general case. Results collected for a population of interest and a set of registered destinations should be compared with an objective, $O$ , as follows: + +**Percent meeting objective (PMO):** The percentage of total destinations with point-to-point performance that is categorized as meeting the stated objective for a specific population of interest. + +The objectives are evaluated over sets of point-to-point parameters, such as the following for FLR: + +$$\frac{\text{Count}(\overline{FLR} | \overline{FLR}_n \leq O_{IPLR})}{\text{Count}(\overline{FLR})} \times 100$$ + +where the $\text{Count}()$ function determines the number of elements in the set that meet the stated condition. + +## 8.8 Organization of parameters according to use case + +This clause categorizes the performance parameters according to the audience most likely to benefit from the results expressed in those terms. In Table 1, customer representatives are the persons responsible for a large community of users, and may act on the user's behalf for contract negotiations or bill-paying. Network operators and individual users are also included. + +**Table 1 – Point-to-multipoint performance parameters organized by use case** + +| | Customer representative-oriented parameters | Network operator-oriented parameters | +|---------------------------|----------------------------------------------------|---------------------------------------------| +| Throughput (rates) | Min and max rates over group | Mean, min and max rates | +| Loss | Group loss ratio | Loss ratio range over group | +| Delay | Global mean | Delay range over group | +| Delay variation | Range over group | Range over group | + +The point-point metrics are best suited for the needs of individual users. + +Availability is important to all categories, and parameters are defined in clause 9. + +# 9 Ethernet service availability + +The Ethernet service availability definition is based on a model which uses two states corresponding to the ability or inability of the network to sustain the service in the available state. Transitions between the states of the model are governed by the occurrence of patterns of severe errored seconds in the Ethernet layer ( $\text{SES}_{\text{ETH}}$ ). This Recommendation views availability from the network perspective, where availability performance is characterized independently of user behaviour. + +## 9.1 Severe errored second ( $\text{SES}_{\text{ETH}}$ ) + +A severe errored second ( $\text{SES}_{\text{ETH}}$ ) outcome occurs for a block of frames observed during a one-second interval at ingress $\text{MP}_0$ when the corresponding FLR (i.e., the ratio of lost frames to total frames in the block) at egress $\text{MP}_1$ exceeds $s_1$ . + +A provisional value $s_1$ of 0.5 is proposed, and different values may also be chosen depending on the class of service (CoS). + +Evaluation of successive one-second intervals is non-overlapping. + +NOTE – Measurement methodologies for the service availability definition are beyond the scope of this Recommendation, and are for further study. The minimum number of frames that should be used in evaluating the $SES_{ETH}$ outcome, $M$ , is one aspect that requires further consideration, along with the state designation when the number of frames present is less than $M$ (when using non-dedicated frames, or live traffic, as a basis for measurement). + +Note that provisional values are subject to change following additional study and real network experience. + +## 9.2 Criteria for entry to and exit from unavailable state + +A period of unavailable time begins at the onset of 10 consecutive $SES_{ETH}$ outcomes. The corresponding period of time is considered to be part of unavailable time. During the unavailable time period, the Ethernet network is in unavailable state. A new period of available time begins at the onset of 10 consecutive non- $SES_{ETH}$ outcomes. The corresponding period of time is considered to be part of available time. During the available time period, the Ethernet network is in available state. Figure 9 illustrates the definition of criteria for transition to/from the unavailable state. + +![Figure 9: Example of unavailability determination. A timeline diagram showing the transition between unavailable and available states based on 10 consecutive severe errored seconds (SES_ETH) or non-severe errored seconds (non-SES_ETH).](7d2d1d3870cd224c4430d19334557716_img.jpg) + +This definition of availability has been chosen to allow comparison with other link layer techniques. + +The diagram illustrates the criteria for entry to and exit from an unavailable state over time. The timeline is represented by a horizontal axis labeled 'Time'. The timeline is divided into segments representing one-second intervals. A legend indicates that a dark gray square represents $SES_{ETH}$ (severe errored second) and a white square represents Non- $SES_{ETH}$ . + +The timeline shows the following sequence of events: + +- An initial period of 10 consecutive $SES_{ETH}$ (dark gray squares). A double-headed arrow labeled '10 $SES_{ETH}$ ' spans this period. Below this, a vertical arrow points to the text 'Unavailability detected'. A horizontal double-headed arrow below the timeline, starting from the beginning of this period, is labeled 'Unavailable period'. +- Following the unavailable period, there is a period of 10 consecutive Non- $SES_{ETH}$ (white squares). A double-headed arrow labeled '10 non- $SES_{ETH}$ ' spans this period. Below this, a vertical arrow points to the text 'Availability detected'. A horizontal double-headed arrow below the timeline, starting from the beginning of this period, is labeled 'Available period'. + +The diagram is identified by the code Y.1563(09)\_F09 in the bottom right corner. + +Figure 9: Example of unavailability determination. A timeline diagram showing the transition between unavailable and available states based on 10 consecutive severe errored seconds (SES\_ETH) or non-severe errored seconds (non-SES\_ETH). + +**Figure 9 – Example of unavailability determination** + +All 10-second intervals evaluated for state determination must be entirely composed of scheduled service time (the time interval when the service is intended to be operational, and is usually specified in a service agreement). This means that all seconds of scheduled service time are evaluated at least once for state determination purposes. + +Because an Ethernet service is bidirectional, an Ethernet network is in the unavailable state if either one, or both directions, are in the unavailable state. The unidirectional availability can be measured by the criteria mentioned above. + +## 9.3 Ethernet service availability parameters + +### 9.3.1 Percent Ethernet service unavailability (PEU) + +The percentage of total scheduled Ethernet service time (the percentage of one-second intervals) that is (are) categorized as unavailable using the Ethernet service availability function. + +### 9.3.2 Percent Ethernet service availability (PEA) + +The percentage of total scheduled Ethernet service time (the percentage of one-second intervals) that is (are) categorized as available using the Ethernet service availability function: + +$$PEU = 100 - PEA$$ + +# Annex A + +## Secondary terminology for assessing delay variation + +(This annex forms an integral part of this Recommendation) + +## A.1 Introduction + +The body of this Recommendation specifies a primary/normative definition for frame delay variation which will be the basis for future numerical objectives on performance of Ethernet services. This annex describes a secondary method based on IETF's inter-packet delay variation as used in the Metro Ethernet Forum (MEF), and briefly lists areas intended for further study. + +## A.2 Definition of IP packet delay variation + +[IETF RFC 3393] defines delay variation as follows: + +- A definition of the IP packet delay variation (IPDV) can be given for packets inside a stream of packets. +- The IPDV of a pair of packets within a stream of packets is defined for a selected pair of packets in the stream going from measurement point MP1 to measurement point MP2. +- The IPDV is the difference between the one-way delay of the selected packets. + +A selection function unambiguously determines the pair of packets used in each calculation of the delay variation metric. Only packets that arrive successfully are used in IPDV calculations. + +The first selection function defined is for adjacent packets in the stream. The one-way delay of the current packet has the one-way delay of the previous packet subtracted from it to determine the current packet's IPDV. If either of the packets in the pair (or both) are lost, then the IPDV is undefined. + +The IETF definition has considerable flexibility. Either the ITU-T Y.1563 2-point frame delay variation parameter (clause 8.1.5) or the MEF 10.1 method described below can be derived by specifying the appropriate selection functions. + +## A.3 Definition of inter-frame delay variation (IFDV) for Ethernet frame transfer + +The IFDV ( $v'_k$ ) is the difference between the frame reference arrival ( $c_k$ ) time and the actual arrival time ( $d_k$ ) at the point of interest, e.g., network egress. + +$$v'_k = d_k - c_k$$ + +Where $c_k = d_j + \tau_{kj}$ , $j < k$ and $\tau_{kj}$ is the inter-arrival time between the j-th and the k-th frames as shown in Figure A.1. The IFDV parameter may take positive and negative values. Negative values are an indication of the network tendency to clump frames together while positive values are an indication of the network tendency to spread frames apart. The relationship between the various delay values is depicted in Figure A.1. Figure A.1 shows a scenario where a frame arrives at the egress before its reference arrival time. + +![Figure A.1 – Inter-frame delay variation. The diagram shows two horizontal lines representing time axes. The top line has two vertical arrows pointing down, labeled 'Frame j' and 'Frame k'. A dashed horizontal line with double-headed arrows between these two points is labeled \tau_{jk}. The bottom line has three vertical arrows pointing down, labeled d_j, d_k, and c_k. Dashed lines connect 'Frame j' to d_j and 'Frame k' to d_k. A dashed horizontal line with double-headed arrows between d_j and d_k is shown. A dashed vertical line with a double-headed arrow between d_k and c_k is also shown. The text 'Y.1563(09)_FA.1' is in the bottom right corner.](692541e65db4dc852988ce77ebb60ce5_img.jpg) + +Figure A.1 – Inter-frame delay variation. The diagram shows two horizontal lines representing time axes. The top line has two vertical arrows pointing down, labeled 'Frame j' and 'Frame k'. A dashed horizontal line with double-headed arrows between these two points is labeled \tau\_{jk}. The bottom line has three vertical arrows pointing down, labeled d\_j, d\_k, and c\_k. Dashed lines connect 'Frame j' to d\_j and 'Frame k' to d\_k. A dashed horizontal line with double-headed arrows between d\_j and d\_k is shown. A dashed vertical line with a double-headed arrow between d\_k and c\_k is also shown. The text 'Y.1563(09)\_FA.1' is in the bottom right corner. + +**Figure A.1 – Inter-frame delay variation** + +Since the inter-frame time $\tau_{ij}$ is generally a variable, one can choose the two frames $j$ and $k$ such that there is a predefined fixed separation between them, $\Delta t$ ( $\tau_{ij} = \Delta t$ , for all $i$ and $j$ ). In this case, the reference arrival for any frame $k$ is equal to: + +$$c_k = d_j + \Delta t$$ + +where $d_j$ is the arrival time of a frame that is separated by time $\Delta t$ from frame $k$ at ingress. + +## **A.4 Summarizing IFDV performance** + +There could be a number of ways for summarizing the IFDV performance. One method that has seen implementation and is used for certification of Ethernet products is that specified in [MEF 10.1]. With this method, the absolute values of the IFDV $|v'_k|$ are taken, and the IFDV value that achieves a predetermined percentile, $P$ , is determined. + +## **A.5 Areas for further study** + +When considering the IFDV method of measurement, the following aspects should be studied further: + +- What value(s) should be recommended for the ingress packet spacing, $\Delta t$ ? +- How many values of $\Delta t$ are necessary to provide a sufficient characterization of network performance? +- Must each frame pair be separated by $\Delta t$ ? Or, should the frame pairs overlap in time? +- What are the measurement applications where this method is suitable? + +# Appendix I + +## Implications of sampling large groups + +(This appendix does not form an integral part of this Recommendation) + +## I.1 Introduction + +There are always limitations on the practical size of the group measurements. Specifically, the scale of large multicast groups tends to prevent measurements at every member destination. + +## I.2 Performance at sample destinations + +It should be permissible to measure at a sub-set of the destinations in a group and report the measured range of loss ratio variation, or other parameters. + +If the sub-set can be selected with knowledge of the multicast tree structure, then all of the tree but the final links to the un-sampled destinations can be assessed. + +![A hierarchical multicast tree diagram. At the top is a node labeled 'SRC'. It branches into two nodes. The left branch further splits into two nodes, which then split again to reach destinations D1, D2, D3, and D4. The right branch from SRC splits into two; one path leads to destinations D5 and D6, while the other path leads to an intermediate node labeled 'MPx'. From 'MPx', the tree branches out to destinations D7, D8, D9, and D10. Arrows indicate the flow from the source down to the destinations.](1b893df61c2b73b7a85e65fc1f58e203_img.jpg) + +Y.1563(09)\_FI.1 + +A hierarchical multicast tree diagram. At the top is a node labeled 'SRC'. It branches into two nodes. The left branch further splits into two nodes, which then split again to reach destinations D1, D2, D3, and D4. The right branch from SRC splits into two; one path leads to destinations D5 and D6, while the other path leads to an intermediate node labeled 'MPx'. From 'MPx', the tree branches out to destinations D7, D8, D9, and D10. Arrows indicate the flow from the source down to the destinations. + +**Figure I.1 – Sample of destinations** + +For example, if the performance of all odd numbered or all even numbered destinations is sampled, then all shared branches and nodes of the tree are assessed. + +Note that the population of interest could be defined as described in the body of this Recommendation, but with the additional qualification "that are successfully delivered to the intermediate node with $MP_{x}$ ". This flexibility allows assessment of a partial multicast tree, where $R_{x}$ becomes the effective $S$ for this population of interest, and frame loss parameter results for destinations 7 through 10 may assist in the isolation of a cause of loss within the tree. + +If objectives are developed for a multicast tree, then the measurement and sampling methodology is critical in determining how the objectives are constructed, and possibly even the numerical values set for the objectives. + +The body of this Recommendation specifies several parameters that emphasize the performance range across all destinations in a group. When a sub-set of destinations is measured, it is possible to report the sample range, or to report the range between several percentiles (1% and 99%, for example) because the true performance range of the group cannot be known with certainty. + +# Appendix II + +## Alternative parameters using the framework of this Recommendation + +(This appendix does not form an integral part of this Recommendation) + +## II.1 Introduction + +It is possible to calculate many different performance parameters using the framework of point-to-point parameters at registered destinations of a multicast group. At the same time, it is impossible to anticipate all the ways that point-to-multipoint parameters might be used, and therefore only the statistics that are anticipated to be relevant for many uses have been specified in the body of this Recommendation. This appendix is intended to give a view of the alternate possibilities. + +## II.2 Point-to-multipoint performance parameters + +The lists that follow give examples of the point-to-multipoint parameters that can be created from frame transfer outcomes and point-to-point parameters. Parameters expressed as ratios are treated separately from continuous-value parameters. + +For the point-to-multipoint case, the atomic measurement results (the point-to-point measurements) can be organized into a matrix where the horizontal axis represents the time and the vertical axis represents the destinations, as in Figure 8. This matrix can be processed by rows (creating point-to-point parameters), by columns (creating vectors describing the performance at all destinations for a given frame transfer attempt) or the entire matrix can be processed. This post-processing could be a minimum/maximum, mean/median or range calculation as well. Then these post-processed parameters can be further post-processed (e.g., a column-maximum can be averaged over time, etc.). + +As an example, the following interpretation is presented: + +Loss (and other outcomes that use a ratio in the parameter): + +- Point-to-point + - Single outcome + - i) a frame is lost/errored/... + - Calculated values for a population of interest + - i) ratio (e.g., Ethernet frame loss ratio in clause 8.4.1) +- Point-to-multipoint + - Ratio + - i) singles ( $\rightarrow$ group vector) + - ii) populations of singles ( $\rightarrow$ whole matrix) + - iii) of ratios + - Mean + - i) of ratios (e.g., mean group loss ratio in clause 8.4.3) + +Delay (and others that produce results in a continuous range): + +- Point-to-point + - Single value + - i) delay of a frame + - ii) delay variation of two frames + +- Calculated values for a population of interest + - i) minimum/maximum + - ii) mean/median + - iii) range +- Point-to-multipoint + - Minimum/maximum + - i) singles (→ group vector) + - ii) populations of singles (→ whole matrix) + - iii) min/mean/range + - Mean/median + - i) singles + - ii) populations of singles (e.g., global mean transfer delay in clause 8.2.1) + - iii) min/mean/range + - Range + - i) singles + - ii) population of singles + - iii) min/mean/range (e.g., mean transfer delay range over group in clause 8.2.3) + +## **II.3 Relationship to other standards** + +MEF defines two types of multipoint services, a tree and a LAN. Neither of these is the same as the point-to-multipoint connection discussed here. However, for comparison purposes and with simplifications, the MEF multipoint delay/delay variation/loss ratio performance can be handled as a maximum of the vector point-to-point performance parameters (at each destination), and the availability performance as the minimum of the vector. Then the performance objectives are defined for these maxima/minima in [MEF 10.1]. + +# Appendix III + +## Harmonizing terminology for frame delay and frame delay variation metrics + +(This appendix does not form an integral part of this Recommendation) + +## III.1 Introduction + +The terminology for frame delay and frame delay variation used in this Recommendation differs somewhat from the terminology used presently by the Metro Ethernet Forum (MEF). For example, this Recommendation specifies a single primary/normative definition for frame delay variation, 2-point frame delay variation, which assesses the variation in a set of one-way delays with respect to a single reference delay (using the minimum delay is strongly recommended as the reference delay). This appendix provides a mapping between similar metrics developed by these two standards bodies. It also discusses other forms of delay variation metrics. + +## III.2 Frame delay and frame delay variation + +In their technical specification [MEF 10.1], the MEF defined its service performance attributes (or metrics) in section 6.9. There are different performance attributes for point-to-point Ethernet virtual connections (EVCs) and multipoint-to-multipoint EVCs. Point-to-point EVCs have exactly two user-to-network interfaces (UNIs), supporting a bidirectional frame transfer service between the designated UNI pair. + +![Diagram of a point-to-point Ethernet virtual connection (EVC) between two user-to-network interfaces (UNIs).](315bdbeafb39026e19b77c26b19d9d1f_img.jpg) + +The diagram illustrates a point-to-point Ethernet virtual connection (EVC) between two user-to-network interfaces (UNIs). On the left is a box labeled 'UNI A' and on the right is a box labeled 'UNI B'. Two horizontal arrows connect them: the top arrow points from UNI B to UNI A, and the bottom arrow points from UNI A to UNI B. The space between the two arrows is labeled 'EVC'. Below the diagram, the text 'Y.1563(09)\_FIII.1' is visible. + +Diagram of a point-to-point Ethernet virtual connection (EVC) between two user-to-network interfaces (UNIs). + +**Figure III.1 – Point-to-point Ethernet virtual connections (EVCs)** + +In most ways, the definition of point-to-point EVC frame delay in [MEF 10.1] is similar to the definition in this Recommendation. One-way delay uses the first bit on ingress and the last bit on egress. However, the *population of interest* in [MEF 10.1] includes successfully transferred frames in both directions on the EVC. This is unusual, and a follow-on effort is in progress to separate the populations by direction (e.g., the population of interest would include frames transferred on the direction). This follow-on work will be captured in an incremental update to [MEF 10.1], provisionally identified as [b-MEF 10.1.1]. + +A service level specification (SLS) for a point-to-point EVC frame delay would be based on a specified percentile of the one-way delay of subscriber traffic submitted during an evaluation time interval, T (the traffic must meet several other qualifications, see [MEF 10.1]). The MEF follow-on work will allow for the calculation of multiple percentiles of the delay distribution. Also, work on [b-MEF 10.1.1] proposes to add a new SLS objective on the difference between two percentiles of the one-way delay of subscriber traffic. This is the foundation for a direct comparison between the MEF performance attributes and the 2-point frame delay variation parameter specified in this Recommendation. + +When the objective for the difference between percentiles (or "one-way frame delay range") is based on the same values used in the 2-point frame delay variation parameter (e.g., the 99.9 percentile and the minimum), then with the other modifications described above, the MEF and ITU-T will be able to specify equivalent metrics. + +The MEF follow-on effort also intends to add a mean one-way frame delay objective, consistent with widespread usage in SLS and this Recommendation. + +## III.3 Inter-frame delay variation + +[b-MEF 10.1.1] clarified that the form of delay variation specified in [MEF 10.1] is more accurately referred to as inter-frame delay variation (IFDV). This attribute is loosely based on [IETF RFC 3393], where the variation is assessed between packets sent with constant time spacing. Thus, the reference delay for each value of delay variation is the delay of a packet following the current packet by a constant $\Delta t$ . Discussions in the follow-on activity have revealed that network characterization requires use of several values of $\Delta t$ (on the order of milliseconds, seconds and tens of seconds). + +IFDV is recognized as another form of delay variation assessment in this appendix and in Annex A. However, the 2-point frame delay variation specified in body of this Recommendation is preferred. + +For one reason, there are tested and verified methods for combining segment measurements to estimate the UNI-to-UNI performance based on the 2-point FDV form (see clause 8 of [b-ITU-T Y.1541] for one such method). + +The ITU-T Y.1541 IP performance objectives for packet delay variation (PDV) are specified in terms of the normative 2-point packet delay variation parameter, which is identical to the 2-point FDV in this Recommendation. This is because objectives using the 2-point PDV have been more straightforward to rationalize (or to relate to real-world networking aspects) than IFDV and similar forms. + +It is worthwhile noting that the IETF IPPM Working Group has completed [b-IETF RFC 5481] comparing the two delay variation metrics in additional dimensions and to provide detailed guidance. [b-IETF RFC 5481] analyses the two forms in order to determine the tasks and circumstances that are most appropriate for each form. + +## III.4 Concatenation of inter-frame delay variation + +The proposed method is an extension of the approach for combining 2-point delay variation measurements that appear in Appendix IV of [b-ITU-T Y.1541]. + +Both these methods employ approximations that produce computationally simple procedures while retaining an accuracy that should be sufficient for many planning purposes. + +Suppose Ethernet frames flow through $n$ network segments, which could be routers or networks themselves. Let $T_k$ denote the 1-point frame delay variation through the $k$ -th segment. The following procedure can be used to estimate the corresponding 1-point frame delay variation $T$ of the flow measured upon output from the $n$ -th (last) segment. Suppose we are given a set of measurements $m_1, m_2, \dots, m_r$ of $|T_k|$ for each $k = 1, 2, \dots, n$ and a fixed probability $p$ . First define $x$ to be the value + +satisfying $\Phi(x) = \frac{p+1}{2}$ where $\Phi$ is the standard normal (mean 0, variance 1) distribution function. + +Then: + +- For each $k$ compute the $p$ -th quantile $t_k$ satisfying $\Pr(|T_k| < t_k) = p$ . + +- For each $k$ compute $\kappa_k = \frac{1}{r} \sum_{i=1}^r m_i^4 - 3 \cdot \sigma_k^4$ where $\sigma_k^2 = \frac{1}{r} \sum_{i=1}^r m_i^2$ . + +NOTE – $\kappa_k$ and $\sigma_k^2$ are in fact the 4th cumulant and variance of $T_k$ . Alternatively, the cumulants can be estimated from the expression: + +$$\kappa_k = 24 \cdot \frac{\sigma_k^4}{x} \cdot \frac{t_k / \sigma_k - x}{x^2 - 3}.$$ + +- Compute the end-to-end variance $\sigma^2$ and 4th cumulant of $T = \sum_{k=1}^n T_k$ as: + +$$\sigma^2 = \sum_{k=1}^n \sigma_k^2 \quad \kappa = \sum_{k=1}^n \kappa_k$$ + +- The $p$ -th quantile $t$ satisfying $\Pr(|T| < t) = p$ is finally computed as: + +$$t = \sigma \cdot x \left\{ 1 + \frac{\kappa}{24 \cdot \sigma^4} (x^2 - 3) \right\}.$$ + +# Appendix IV + +## Networking technologies making use of Ethernet + +(This appendix does not form an integral part of this Recommendation) + +Different networking opportunities can make use of Ethernet. This appendix, which requires further study, will summarize the raw definitions of VLAN, PB (provider bridging) and PBB (provider backbone bridging). These technologies correspond to different encapsulations of Ethernet frames as shown in Figure IV.1. + +![Diagram showing the encapsulation of Ethernet frames for IEEE 802.1 Ethernet, IEEE 802.1Q VLAN, IEEE 802.1ad PB, and IEEE 802.1ah PBB.](b58cedaf15ad4f0edee5621820865ccc_img.jpg) + +The diagram illustrates the encapsulation of Ethernet frames for four different technologies. Each frame is represented as a vertical stack of layers, with dashed lines indicating the mapping between corresponding layers across the different technologies. + +| IEEE 802.1 Ethernet | IEEE 802.1Q VLAN | IEEE 802.1ad PB | IEEE 802.1ah PBB | +|--------------------------|--------------------------|--------------------------|---------------------| +| FCS | FCS | FCS | FCS | +| Payload | Payload | Payload | Payload | +| EtherType:
e.g. 08-00 | EtherType:
e.g. 08-00 | EtherType:
e.g. 08-00 | I-TAG | +| SA | Q-TAG | C-TAG | EtherType:
88-e7 | +| DA | EtherType:
81-00 | EtherType:
81-00 | B-TAG | +| | SA | EtherType:
88-a8 | EtherType:
88-a8 | +| | DA | SA | B-SA | +| | | DA | B-DA | + +The diagram shows that the IEEE 802.1 Ethernet frame is the base. IEEE 802.1Q VLAN adds a Q-TAG (EtherType: 81-00) and a new SA/DA. IEEE 802.1ad PB adds a C-TAG (EtherType: 81-00) and an S-TAG (EtherType: 88-a8). IEEE 802.1ah PBB adds an I-TAG (EtherType: 88-e7), a B-TAG (EtherType: 88-a8), and a B-SA/B-DA. + +Diagram showing the encapsulation of Ethernet frames for IEEE 802.1 Ethernet, IEEE 802.1Q VLAN, IEEE 802.1ad PB, and IEEE 802.1ah PBB. + +Y.1563(09)\_FIV.1 + +**Figure IV.1 – Different Ethernet technologies** + +# Appendix V + +## OAM measurement considerations + +(This appendix does not form an integral part of this Recommendation) + +## V.1 Introduction + +Operation, administration and management (OAM) systems can introduce various types of maintenance frames into the subscriber traffic. This appendix examines the differences between OAM methods of measurement and the corresponding parameters defined in this Recommendation. + +One type of OAM frame conveys frame counts at a particular MP, an ingress UNI MP, for example. Assuming that the MP counter only counts frames intended for some egress UNI MP, then the ingress count can be compared with the egress count to determine whether any frames were lost. + +This Recommendation defines loss by tracking the transfer of *corresponding frames* between MPs, and uses a waiting time threshold to distinguish between loss and unlikely long delay. In practice, all frames have a useful lifetime. Thus, the waiting time, $T_{\max}$ , can be set fairly long (on the order of seconds). If the apparent delay of a frame exceeds $T_{\max}$ , then the frame is declared lost. + +The OAM counter system does not use a rigorous time-out to determine frame loss. This appendix examines the ramifications of the OAM approach. + +## V.2 Loss performance based on counters + +When OAM counter packets are introduced into a stream on a periodic basis, the delay variation influences the ingress frame counts. The ingress count can be quite accurate. However, the following factors influence the accuracy of the egress counts: + +- 1) Frames may be counted at one MP which did not pass the other MP. +- 2) Assuming that frame order cannot be changed by the network, the arrival of an OAM frame indicates that no more frames applying to the count in that OAM packet can possibly arrive. +- 3) Where the order of frame delivery can change between MPs, then the frame counts carried in OAM frames may not be valid. This is especially true when the OAM frame itself is delivered out-of-order, or when a frame re-ordering event takes place in the vicinity of an OAM frame. + +The interval between OAM counter frames, $T_{\text{OAM}}$ , plus the one-way delay of the OAM frame, determines the maximum waiting time for frame arrival at a given counter location. $T_{\text{OAM}}$ may not be equal to $T_{\max}$ , and thus the waiting time applied in an OAM measurement may differ from the specified $T_{\max}$ . + +# Appendix VI + +## Mapping to Recommendation ITU-T G.8010 terms and conventions (and to those of other associated Recommendations) + +## VI.1 Introduction + +The body of this Recommendation uses the terminology and architectural conventions for connectionless networks that were developed beginning with [ITU-T I.380] ([ITU-T I.380] was renumbered [ITU-T Y.1540] a year later), for IP-based network service performance. This terminology and architecture has been adapted to the specific case of Ethernet connectionless networks, as it was for [b-ITU-T Y.1561] (MPLS) in 2004. + +A telecommunication network is a complex network which can be described in a number of different ways, depending on the purpose of the description, and therefore other Recommendations may use alternate terminology and conventions. For example, [ITU-T G.8010] relies on other Recommendations developed to serve the needs of Study Group 15. This appendix provides a mapping between key terms of [ITU-T G.8010] and this Recommendation. Annexes A and B of [b-ITU-T G.8011] also provide a mapping between Ethernet service attributes/interfaces and the architecture of [ITU-T G.8010]. + +## VI.2 Mapping between Ethernet network performance and architecture Recommendations + +**Table VI.1 – Mapping between sets of terminology** + +| ITU-T Y.1563 | ITU-T G.8010 ETH | +|--------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Source (SRC) | Flow termination source. | +| Destination (DST) | Flow termination sink. | +| Measurement point (MP) | Possibly a maintenance entity associated with an access point, flow point, or a termination flow point. | +| Point-to-point topology (2 MP) | Possibly Ethernet access groups with a point-to-point relationship association, and the Ethernet flow domains and Ethernet flow point pool links between them. | +| Point-to-multipoint topology ( $n > 2$ MP) | Possibly Ethernet access groups with a point-to-multipoint relationship association, and the Ethernet flow domains and Ethernet flow point pool links between them (also known as a rooted multipoint Ethernet VLAN). | +| Bridge* | Special case of a flow domain. | +| Exchange link | Flow point pool link, link flow domain fragment, or link connection when used to connect a user's flow domain to a network provider's flow domain (access link), or when used to connect between provider's flow domains. | +| Network section | Possibly a flow domain, (sub)network flow domain fragment which is under a single jurisdictional boundary. | +| Network section ensemble | One or more flow domains or (sub)network flow domain fragments (connected by flow point pool links), or an entire layer network. | +| Virtual LAN (VLAN)* | Possibly a flow point pool component link and corresponding flow domain fragment(s). | + +**Table VI.1 – Mapping between sets of terminology** + +| ITU-T Y.1563 | ITU-T G.8010 ETH | +|----------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------| +| End-to-end Ethernet network | Possibly a layer network, (sub)network flow domain fragment, or connectionless trail. | +| Population of interest | Possibly a flow domain flow, or a flow domain fragment. | +| * New term in this Recommendation, not used in earlier Recommendations on performance. | | + +Measurement points (MPs) may be assigned in the architecture wherever needed (and practical). For example, measurement points may be located at the ETH access point between the ETH/client adaptation function and the ETH flow termination function, or between the ETH/ETH adaptation function and the ETH flow termination function. ETH service performance may be monitored between MP at ETH layer access points (NC-MEG) or ETH sublayer access points (TC-MEG, LC-MEG). MP at ETH (sub)layer access points may be located in UNI-C ports, UNI-N ports and E-NNI ports. Note that one port may contain more than one measurement point for an ETH flow domain fragment. + +![Figure VI.1: Example mapping between Figure 2 of this Recommendation and Figure 4 of [ITU-T G.8010]. The diagram illustrates the mapping between higher layer performance, Ethernet service performance (Y.1563), and lower layer performance (3 instances). It shows user information (e.g., data) flowing through IP, MPLS, and Ethernet layers, then through Ethernet layers, LL (Link Layer), and Bridge components, and finally through SRC, Link, Bridge, Link, Bridge, Link, and DST components. The lower layer performance is mapped to ETH FP (Flow Point), ETH FD (Flow Domain), ETH FDF (Flow Domain Fragment), and ETH LF (Link Fragment) components.](9252ccfbbe9e34cb108f0060f2b563f1_img.jpg) + +The diagram illustrates the mapping between higher layer performance, Ethernet service performance (Y.1563), and lower layer performance (3 instances). It shows user information (e.g., data) flowing through IP, MPLS, and Ethernet layers, then through Ethernet layers, LL (Link Layer), and Bridge components, and finally through SRC, Link, Bridge, Link, Bridge, Link, and DST components. The lower layer performance is mapped to ETH FP (Flow Point), ETH FD (Flow Domain), ETH FDF (Flow Domain Fragment), and ETH LF (Link Fragment) components. + +Y.1563(09)\_FVI.1 + +Figure VI.1: Example mapping between Figure 2 of this Recommendation and Figure 4 of [ITU-T G.8010]. The diagram illustrates the mapping between higher layer performance, Ethernet service performance (Y.1563), and lower layer performance (3 instances). It shows user information (e.g., data) flowing through IP, MPLS, and Ethernet layers, then through Ethernet layers, LL (Link Layer), and Bridge components, and finally through SRC, Link, Bridge, Link, Bridge, Link, and DST components. The lower layer performance is mapped to ETH FP (Flow Point), ETH FD (Flow Domain), ETH FDF (Flow Domain Fragment), and ETH LF (Link Fragment) components. + +**Figure VI.1 – Example mapping between Figure 2 of this Recommendation and Figure 4 of [ITU-T G.8010]** + +![Figure VI.2: Example mapping between Figure 3 of this Recommendation and Figure 6 of [ITU-T G.8010]. The diagram illustrates the mapping between the Ethernet layer and the lower layer across a network section. At the top, the Ethernet layer shows a sequence of frames A, B, C, and D. Frame A is sent from a Bridge or SRC, frame B from a Bridge, frame C from a Bridge, and frame D from a Bridge or DST. These frames are mapped to the lower layer via Maintenance Points (MP). The lower layer shows the internal structure of the frames, including the Ethernet Flow Domain (ETH FDF) and the Ethernet Termination Function (ETH(T)FP). The diagram also shows the mapping of the frames to the lower layer via the Exchange link. The lower layer shows the internal structure of the frames, including the Ethernet Flow Domain (ETH FDF) and the Ethernet Termination Function (ETH(T)FP). The diagram also shows the mapping of the frames to the lower layer via the Exchange link. The lower layer shows the internal structure of the frames, including the Ethernet Flow Domain (ETH FDF) and the Ethernet Termination Function (ETH(T)FP).](798679874d1c29f8343506a156c79d7e_img.jpg) + +NOTE 1 – Ethernet exit events for frames A and C. +NOTE 2 – Ethernet entry events for frames B and D. + +Y.1563(09)\_FV1.2 + +Figure VI.2: Example mapping between Figure 3 of this Recommendation and Figure 6 of [ITU-T G.8010]. The diagram illustrates the mapping between the Ethernet layer and the lower layer across a network section. At the top, the Ethernet layer shows a sequence of frames A, B, C, and D. Frame A is sent from a Bridge or SRC, frame B from a Bridge, frame C from a Bridge, and frame D from a Bridge or DST. These frames are mapped to the lower layer via Maintenance Points (MP). The lower layer shows the internal structure of the frames, including the Ethernet Flow Domain (ETH FDF) and the Ethernet Termination Function (ETH(T)FP). The diagram also shows the mapping of the frames to the lower layer via the Exchange link. The lower layer shows the internal structure of the frames, including the Ethernet Flow Domain (ETH FDF) and the Ethernet Termination Function (ETH(T)FP). The diagram also shows the mapping of the frames to the lower layer via the Exchange link. The lower layer shows the internal structure of the frames, including the Ethernet Flow Domain (ETH FDF) and the Ethernet Termination Function (ETH(T)FP). + +**Figure VI.2 – Example mapping between Figure 3 of this Recommendation and Figure 6 of [ITU-T G.8010]** + +## VI.3 In-service measurement and applicability of performance and availability parameters + +Frame transfer delay (clause 8.1) and frame transfer delay variation (clause 8.1.5) are applicable between ingress and egress points of a maintenance entity group (MEG) level within an ETH flow domain fragment. + +For the in-service monitoring ETH-CCM with its CC, LM and RDI, functions may be used to monitor the performance of an ETH flow domain fragment. An ETH flow domain fragment may have three types of maintenance entity groups (MEGs); one network connection MEG, up to six tandem connection MEGs and up to one link connection MEG. The performance of each MEG level in an ETH flow domain fragment is monitored in-service by means of an MEG level-specific ETH-CCM. The presence of lost or spurious frames is determined by counting the transmitted frames with a specific priority in the ETH flow termination source function, transmitting this value in the CCM frame, counting the received frames with this priority in the ETH flow termination sink function, extracting the transmitted frame count values from the incoming CCM frames and processing this information. Note that the CCM bit rate (100 ms period) is 7.2 kbit/s. [b-ITU-T Y.1731], [b-ITU-T G.8021], [b-ITU-T G.8051] and [b-ITU-T G.7710] should be consulted for additional specifications on in-service monitoring. + +The ETH-CC function (supported in the ETH-CCM OAM) is one in-service monitoring function which determines if there is continuity and connectivity. Loss of continuity and/or incorrect connectivity will result in LOC and MMG defects. Those defects contribute to the defect second performance parameter and are the first contribution to the error performance primitives of the ETH flow domain fragment (indicate 100% frame loss). In addition, ETH-LM function (supported in the ETH-CCM OAM) is available for 2-port ETH flow domain fragments to determine the frame loss during periods without loss of continuity or wrong connectivity conditions. ETH-CCM is very important, but it is only one option for performance monitoring (and not ideal for some aspects of the task). + +# Bibliography + +- [b-ITU-T G.707] Recommendation ITU-T G.707/Y.1322 (2003), *Network node interface for the synchronous digital hierarchy (SDH)*. +- [b-ITU-T G.709] Recommendation ITU-T G.709/Y.1331 (2001), *Interfaces for the Optical Transport Network (OTN)*. +- [b-ITU-T G.827] Recommendation ITU-T G.827 (2003), *Availability performance parameters and objectives for end-to-end international constant bit-rate digital paths*. +- [b-ITU-T G.7041] Recommendation ITU-T G.7041/Y.1303 (2001), *Generic framing procedure (GFP)*. +- [b-ITU-T G.7042] Recommendation ITU-T G.7042/Y.1303 (2001), *Link capacity adjustment scheme (LCAS) for virtual concatenated signals*. +- [b-ITU-T G.7710] Recommendation ITU-T G.7710/Y.1701 (2007), *Common equipment management function requirements*. +- [b-ITU-T G.8011] Recommendation ITU-T G.8011/Y.1307 (2004), *Ethernet over Transport – Ethernet services framework*. +- [b-ITU-T G.8011.1] Recommendation ITU-T G.8011.1/Y.1307.1 (in force), *Ethernet private line service*. +- [b-ITU-T G.8011.2] Recommendation ITU-T G.8011.2/Y.1307.2 (2005), *Ethernet virtual private line service*. +- [b-ITU-T G.8012] Recommendation ITU-T G.8012/Y.1308 (2004), *Ethernet UNI and Ethernet NNI*. +- [b-ITU-T G.8021] Recommendation ITU-T G.8021/Y.1341 (2007), *Characteristics of Ethernet transport network equipment functional blocks*. +- [b-ITU-T G.8051] Recommendation ITU-T G.8051/Y.1345 (2007), *Management aspects of the Ethernet-over-Transport (EoT) capable network element*. +- [b-ITU-T I.350] Recommendation I.350 (1993), *General aspects of quality of service and network performance in digital networks, including ISDNs*. +- [b-ITU-T I.380] Recommendation ITU-T I.380 (1999), *Internet protocol data communication service – IP packet transfer and availability performance parameters*. +- [b-ITU-T Y.1540] Recommendation ITU-T Y.1540 (2007), *Internet protocol data communication service – IP packet transfer and availability performance parameters*. +- [b-ITU-T Y.1541] Recommendation ITU-T Y.1541 (2006), *Network performance objectives for IP-based services*. +- [b-ITU-T Y.1561] Recommendation ITU-T Y.1561 (2004), *Performance and availability parameters for MPLS networks*. +- [b-ITU-T Y.1730] Recommendation ITU-T Y.1730 (2004), *Requirements for OAM functions in Ethernet-based networks and Ethernet services*. + +- [b-ITU-T Y.1731] Recommendation ITU-T Y.1731 (2008), *OAM functions and mechanisms for Ethernet based networks*. +- [b-IEEE 802] IEEE 802 (2001), *IEEE Standard for Local and Metropolitan Area Networks: Overview and Architecture*. +- [b-IEEE 802.1D] IEEE 802.1D (2004), *IEEE Standard for Local and metropolitan area networks: Media Access Control (MAC) Bridges*. +- [b-IEEE 802.1Q] IEEE 802.1Q (2005), *IEEE standard for Local and metropolitan area networks: Virtual bridged local area networks*. +- [b-IETF RFC 5481] IETF RFC 5481 (2009), *Packet Delay Variation Applicability Statement*. +- [b-MEF 10.1.1] MEF 10.1.1 (2007), *Amendment to Ethernet Services Attributes Phase 2*. +- [b-MEF 6] MEF 6 (2004), *Metro Ethernet Services Definitions Phase I*. + + + +# SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|--------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/Y/T-REC-Y.1903-201401-I_PDF-E/4e4be0bd8b235167902f2c03e41da651_img.jpg b/marked/Y/T-REC-Y.1903-201401-I_PDF-E/4e4be0bd8b235167902f2c03e41da651_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..e0acd1e05452e14f293727d0f2220710fd23b132 --- /dev/null +++ b/marked/Y/T-REC-Y.1903-201401-I_PDF-E/4e4be0bd8b235167902f2c03e41da651_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:dcac7d9dfe4bcd873e7714c383995f0bb3dce868775b8eea40e5a554e83bed9c +size 34166 diff --git a/marked/Y/T-REC-Y.1903-201401-I_PDF-E/724c7777b608e53be38b12b6fb3c43bc_img.jpg b/marked/Y/T-REC-Y.1903-201401-I_PDF-E/724c7777b608e53be38b12b6fb3c43bc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..6b1f3c07bfe3a2a94dfd4ff033ab461a5ee584a5 --- /dev/null +++ b/marked/Y/T-REC-Y.1903-201401-I_PDF-E/724c7777b608e53be38b12b6fb3c43bc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:eb009e15c96e7f34a2ae6bd828ff1bc03c3b5879d1baa5096ba32e7eb45ed1e2 +size 113307 diff --git a/marked/Y/T-REC-Y.1903-201401-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg b/marked/Y/T-REC-Y.1903-201401-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..ddc2d86595291397b6e9e8f6cbafc0364c5f7181 --- /dev/null +++ b/marked/Y/T-REC-Y.1903-201401-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:bdd2ea26596b0a128c2e6f6216e4312884aa3acf2448cd3553f4604f94c06ead +size 6552 diff --git a/marked/Y/T-REC-Y.1903-201401-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg b/marked/Y/T-REC-Y.1903-201401-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..ccf7fca2058e2640805fc798593012c41b42b41b --- /dev/null +++ b/marked/Y/T-REC-Y.1903-201401-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:12b0234ebee2c94d9f259c6ba2f380ee856196126acf156a281556789f304905 +size 56387 diff --git a/marked/Y/T-REC-Y.1903-201401-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg b/marked/Y/T-REC-Y.1903-201401-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..9bd8c08097bf5bd64245267f30f21ef711e92d2b --- /dev/null +++ b/marked/Y/T-REC-Y.1903-201401-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:989334ad8af7898f0f09640c2636910cd986750790c1f50c26e15239938dea3a +size 217251 diff --git a/marked/Y/T-REC-Y.1903-201401-I_PDF-E/raw.md b/marked/Y/T-REC-Y.1903-201401-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..0e53d7ca1daee39ce63bf2ad9f3d110445177780 --- /dev/null +++ b/marked/Y/T-REC-Y.1903-201401-I_PDF-E/raw.md @@ -0,0 +1,538 @@ + + +I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +# Y.1903 + +(01/2014) + +SERIES Y: GLOBAL INFORMATION +INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS +AND NEXT-GENERATION NETWORKS + +Internet protocol aspects – IPTV over NGN + +# --- Functional requirements of mobile IPTV + +Recommendation ITU-T Y.1903 + +![ITU logo: A blue globe with red lightning bolts and the text 'ITU International Telecommunication Union'.](84a1d09fb489061482111515543b60dc_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with two red lightning bolts striking it. To the right of the globe, the text "ITU" is written in a large, bold, blue font, and below it, the words "International Telecommunication Union" are written in a smaller, blue font. + +ITU logo: A blue globe with red lightning bolts and the text 'ITU International Telecommunication Union'. + +# ITU-T Y-SERIES RECOMMENDATIONS + +# GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS + +| | | +|--------------------------------------------------------------------|---------------| +| GLOBAL INFORMATION INFRASTRUCTURE | | +| General | Y.100–Y.199 | +| Services, applications and middleware | Y.200–Y.299 | +| Network aspects | Y.300–Y.399 | +| Interfaces and protocols | Y.400–Y.499 | +| Numbering, addressing and naming | Y.500–Y.599 | +| Operation, administration and maintenance | Y.600–Y.699 | +| Security | Y.700–Y.799 | +| Performances | Y.800–Y.899 | +| INTERNET PROTOCOL ASPECTS | | +| General | Y.1000–Y.1099 | +| Services and applications | Y.1100–Y.1199 | +| Architecture, access, network capabilities and resource management | Y.1200–Y.1299 | +| Transport | Y.1300–Y.1399 | +| Interworking | Y.1400–Y.1499 | +| Quality of service and network performance | Y.1500–Y.1599 | +| Signalling | Y.1600–Y.1699 | +| Operation, administration and maintenance | Y.1700–Y.1799 | +| Charging | Y.1800–Y.1899 | +| IPTV over NGN | Y.1900–Y.1999 | +| NEXT GENERATION NETWORKS | | +| Frameworks and functional architecture models | Y.2000–Y.2099 | +| Quality of Service and performance | Y.2100–Y.2199 | +| Service aspects: Service capabilities and service architecture | Y.2200–Y.2249 | +| Service aspects: Interoperability of services and networks in NGN | Y.2250–Y.2299 | +| Enhancements to NGN | Y.2300–Y.2399 | +| Network management | Y.2400–Y.2499 | +| Network control architectures and protocols | Y.2500–Y.2599 | +| Packet-based Networks | Y.2600–Y.2699 | +| Security | Y.2700–Y.2799 | +| Generalized mobility | Y.2800–Y.2899 | +| Carrier grade open environment | Y.2900–Y.2999 | +| FUTURE NETWORKS | Y.3000–Y.3499 | +| CLOUD COMPUTING | Y.3500–Y.3999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T Y.1903 + +# Functional requirements of mobile IPTV + +## Summary + +Recommendation ITU-T Y.1903 describes detailed functional requirements of mobile IPTV, which is an application of IPTV (Recommendation ITU-T Y.1901). It applies to where the IPTV terminal device is connected to the IPTV service provider via an IPTV-enabled mobile network to provide the IPTV services irrespective of changes of the location or technical environment. This Recommendation focuses on the requirements for networking aspects of an IPTV terminal device to the IPTV service provider. This Recommendation does not address the common functional requirements of an IPTV service, which are covered by Recommendation ITU-T Y.1901, but provides the requirements specific to mobile IPTV services only. Thus, these functional requirements are used to develop the detailed specifications of the IPTV functional components which are defined in Recommendation ITU-T Y.1910 for support of mobile IPTV. + +## History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|----------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T Y.1903 | 2014-01-13 | 13 | 11.1002/1000/12070 | + +## Keywords + +Broadcast, functional requirements, IPTV, mobile IPTV, multicast. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. For example, . + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2014 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|--------------------------------------------------------------------------|-------------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 2 | +| 4 Abbreviations and acronyms ..... | 3 | +| 5 Conventions ..... | 4 | +| 6 Overview ..... | 4 | +| 6.1 Architectural aspects of mobile IPTV ..... | 4 | +| 6.2 Technical issues of mobile IPTV ..... | 7 | +| 7 Functional requirements of mobile IPTV ..... | 8 | +| 7.1 General requirements of mobile IPTV ..... | 8 | +| 7.2 Functional requirements of service aspects ..... | 8 | +| 7.3 Functional requirements of networking aspects ..... | 9 | +| 7.4 Functional requirements of QoS and QoE aspects ..... | 12 | +| 7.5 Functional requirements of mobile IPTV terminal device aspects ..... | 12 | +| 8 Security considerations ..... | 13 | +| Bibliography..... | 14 | + + + +# Recommendation ITU-T Y.1903 + +# Functional requirements of mobile IPTV + +# 1 Scope + +This Recommendation describes detailed functional requirements of mobile IPTV, which is an application of IPTV [ITU-T Y.1901]. It applies to where the IPTV terminal device is connected to the IPTV service provider via an IPTV-enabled mobile network to provide the IPTV services irrespective of changes of the location or technical environment. This Recommendation focuses on the requirements for networking aspects between an IPTV terminal device and an IPTV service provider. This Recommendation does not address the common functional requirements of IPTV service, which are covered by [ITU-T Y.1901] but provides the requirements specific to mobile IPTV services only. Thus, these functional requirements are used to develop the detailed specifications of the IPTV functional components which are defined in [ITU-T Y.1910] for support of mobile IPTV. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- [ITU-T X.1191] Recommendation ITU-T X.1191 (2009), *Functional requirements and architecture for IPTV security aspects*. +- [ITU-T X.1196] Recommendation ITU-T X.1196 (2012), *Framework for the downloadable service and content protection system in the mobile Internet Protocol television environment*. +- [ITU-T Y.1901] Recommendation ITU-T Y.1901 (2008), *Requirements for the support of IPTV services*. +- [ITU-T Y.1910] Recommendation ITU-T Y.1910 (2008), *IPTV functional architecture*. +- [ITU-T Y.2201] Recommendation ITU-T Y.2201 (2009), *Requirements and capabilities for ITU-T NGN*. + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 home network** [b-ITU-T Q.1706]: The network to which a mobile user is normally connected, or the service provider with which the mobile user is associated, and where the user's subscription information is managed. + +**3.1.2 Internet Protocol Television (IPTV)** [ITU-T Y.1901]: Multimedia services such as television/video/audio/text/graphics/data delivered over IP-based networks managed to support the required level of QoS/QoE, security, interactivity and reliability. + +**3.1.3 IPTV terminal function (ITF)** [ITU-T Y.1901]: The end-user function(s) associated with a) receiving and responding to network control channel messages regarding session set-up, maintenance, and tear-down, and b) receiving the content of an IP transport from the network and rendering. + +**3.1.4 IPTV terminal device** [ITU-T Y.1901]: A terminal device which has ITF functionality, e.g., a STB. + +**3.1.5 mobile network** [b-ITU-T Y.2091], clause 9: A network that provides wireless access to its services and supports mobility. + +**3.1.6 multicast** [b-ITU-T G.9959]: A type of communication when a node sends the same frame simultaneously to one or more other nodes in the network. + +**3.1.7 nomadism** [b-ITU-T Q.1761]: Ability of the user to change his network access point after moving; when changing the network access point, the user's service session is completely stopped and then started again, i.e., there is no handover possible. It is assumed that the normal usage pattern is that users shutdown their service session before moving to another access point or changing terminal. This is the mobility alluded to in the case of fixed mobile convergence. + +**3.1.8 personal mobility** [b-ITU-T Q.1761]: Ability of a user to access telecommunication services at any terminal on the basis of a personal identifier, and the capability of the network to provide those services according to the user's service profile. Note that personal mobility involves the network capability to locate the terminal associated with the user for the purposes of addressing, routing and charging of the user's calls. + +**3.1.9 service** [ITU-T Y.1901]: A set of functionalities enabled by a provider for end-users. + +NOTE – Example provisioned functionalities include IP connectivity with managed quality of service, video-on-demand. + +**3.1.10 service mobility** [b-ITU-T H.510]: The ability of a user to use the particular (subscribed) service irrespective of the location of the user and the terminal that is used for that purpose. + +**3.1.11 terminal device (TD)** [ITU-T Y.1901]: An end-user device which typically presents and/or processes the content, such as a personal computer, a computer peripheral, a mobile device, a TV set, a monitor, a VoIP terminal or an audiovisual media player. + +**3.1.12 terminal mobility** [b-ITU-T Q.1761]: Ability of a terminal to access telecommunication services from different locations and while in motion, and the capability of the network to identify and locate that terminal. + +**3.1.13 visited network** [b-ITU-T Q.1706]: The network outside a home network that provides service to a mobile user. This term is more business significant than geographically significant. + +**3.1.14 wireless network characteristics** [ITU-T Y.1901]: The characteristics of a wireless network expressed in terms of the current available bandwidth, packet loss and possibly other wireless network information parameters for a specific wireless link type, e.g., WLAN, cellular, WPAN or WMAN. + +## 3.2 Terms defined in this Recommendation + +This Recommendation defines the following terms: + +**3.2.1 broadcast** (based on [b-ITU-T G.9959]): A type of communication where a node sends the same frame simultaneously to all other network nodes within a direct range. + +**3.2.2 broadcast service:** A service using broadcast technology to deliver information simultaneously from a single sender to every receiver on the network. + +**3.2.3 broadcast service region:** A service region providing broadcast service(s) to mobile IPTV TDs. + +**3.2.4 mobile IPTV:** An application of IPTV as specified in [ITU-T Y.1901]. It applies to where the IPTV terminal device is connected to the IPTV service provider via an IPTV-enabled mobile network. It must be able to communicate and access services irrespective of changes of the location or technical environment. + +NOTE – There are multiple possible levels of mobility, from nomadism, where IPTV service is resumed only after the move is complete, to full mobility, where IPTV service is continuous throughout the movement. + +**3.2.5 mobile IPTV TD:** An IPTV terminal device supporting mobile IPTV. + +**3.2.6 mobility** (defined as 'generalized mobility' in [b-ITU-T Y.2001]): The ability for the user or other mobile entities to communicate and access services irrespective of changes of the location or technical environment. The degree of service availability may depend on several factors including the access network capabilities, service level agreements between the user's home network and the visited network (if applicable), etc. Mobility includes the ability of telecommunication with or without service continuity. + +**3.2.7 multicast service:** A service using multicast technology to deliver information simultaneously from a single sender to multiple receivers belonging to a specific service group. + +**3.2.8 multicast service region:** A service region providing multicast service(s) to mobile IPTV TDs. + +**3.2.9 radio resources:** Available bandwidth in the mobile access network to provide services to mobile IPTV TDs. + +**3.2.10 service region:** A logical area, consisting of more than one base station (BS) or access point (AP) of the mobile access network, used to provide in an efficient way the same services to all mobile IPTV TDs connected to that service region. + +NOTE – As an example, in a 3G mobile access network, a service region consists of several neighbouring cells. + +# 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|------|--------------------------------------------| +| AAA | Authentication, Authorization, Accounting | +| AP | Access Point | +| BS | Base Station | +| IPTV | Internet Protocol Television | +| ITF | IPTV Terminal Function | +| MBMS | Multimedia Broadcast and Multicast Service | + +| | | +|-------|-------------------------------------------------------------| +| MBS | Multicast and Broadcast Service | +| MCBCS | MultiCast and BroadCast Service | +| QoE | Quality of Experience | +| QoS | Quality of Service | +| SVC | Scalable Video Coding | +| TD | Terminal Device | +| xDSL | Any of the various types of Digital Subscriber Lines (DSLs) | + +# 5 Conventions + +In this Recommendation: + +The keywords "is required to" indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this Recommendation is to be claimed. + +The keywords "is prohibited from" indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this Recommendation is to be claimed. + +The keywords "is recommended" indicate a requirement which is recommended but which is not absolutely required. Thus this requirement need not be present to claim conformance. + +The keywords "is not recommended" indicate a requirement which is not recommended but which is not specifically prohibited. Thus, conformance with this specification can still be claimed even if this requirement is present. + +The keywords "can optionally" indicate an optional requirement which is permissible, without implying any sense of being recommended. This term is not intended to imply that the vendor's implementation must provide the option and the feature can be optionally enabled by the network operator/service provider. Rather, it means the vendor may optionally provide the feature and still claim conformance with the specification. + +# 6 Overview + +## 6.1 Architectural aspects of mobile IPTV + +Mobile IPTV is defined as an IPTV application as specified in [ITU-T Y.1901] and applies to where the IPTV terminal devices (IPTV TDs) of the end-user domain are connected to the IPTV service provider via an IPTV-enabled mobile network. With an IPTV-enabled mobile network, it is intended to indicate here a mobile network connecting mobile IPTV TDs, which provides resource control capabilities to support the QoS required by the end user of mobile IPTV. + +The basic network configuration of mobile IPTV is shown in Figure 1 in accordance with the IPTV domains as described in [ITU-T Y.1910]. + +![Figure 1: Basic network configuration of mobile IPTV with the IPTV domains. The diagram is divided into four vertical sections. The first section, labeled 'End-user', contains an 'IPTV TD' (represented by a monitor and a set-top box) and a 'Mobile IPTV TD' (represented by a smartphone). A blue cloud labeled 'IPTV-enabled mobile network' connects the two. The second section, 'Network provider', shows a central router connected to a server. The third section, 'Service provider', shows a server connected to a database. The fourth section, 'Content provider', shows a globe connected to a server. All sections are interconnected by a horizontal line.](cfef993dcc8fb513de79eb1f93cf26ae_img.jpg) + +The diagram illustrates the basic network configuration of mobile IPTV, divided into four domains: End-user, Network provider, Service provider, and Content provider. The End-user domain includes an IPTV TD (Internet Protocol Television Terminal Device) and a Mobile IPTV TD (Mobile Internet Protocol Television Terminal Device), both connected to an IPTV-enabled mobile network. The Network provider domain includes a central router and a server. The Service provider domain includes a server and a database. The Content provider domain includes a globe and a server. All domains are interconnected by a horizontal line. + +Figure 1: Basic network configuration of mobile IPTV with the IPTV domains. The diagram is divided into four vertical sections. The first section, labeled 'End-user', contains an 'IPTV TD' (represented by a monitor and a set-top box) and a 'Mobile IPTV TD' (represented by a smartphone). A blue cloud labeled 'IPTV-enabled mobile network' connects the two. The second section, 'Network provider', shows a central router connected to a server. The third section, 'Service provider', shows a server connected to a database. The fourth section, 'Content provider', shows a globe connected to a server. All sections are interconnected by a horizontal line. + +Y.1903(14)\_F01 + +**Figure 1 – Basic network configuration of mobile IPTV with the IPTV domains** + +The basic IPTV architectural overview diagram is shown in Figure 2 of [ITU-T Y.1910]. + +NOTE – As detailed in Figure 2, the IPTV TD can also be connected to a home network through network attachment devices such as home gateways, access point devices, etc. + +![IPTV architectural overview diagram showing four main functional areas: End-user functions, Application functions, Service control functions, and Network functions, along with Management and Content provider functions.](d4af765160d04ecef538e5066006dc77_img.jpg) + +The diagram illustrates the IPTV architectural overview, organized into several functional blocks and their interactions: + +- End-user functions (Red box):** + - IPTV terminal functions:** Includes Application client functions and SCP client functions. Application client functions connect to the Transaction protocol. + - Content delivery client functions:** Includes Content delivery client functions and Control client functional block. Content delivery client functions connect to the Multicast delivery control protocol. + - Home network functions:** Includes the Delivery network gateway functional block. It connects to the Authentication and configuration protocol. +- Application functions (Blue box):** + - IPTV application functions:** Connects to the Transaction protocol and the Application profile functional block. + - Application profile functional block:** Connects to the SCP functions. + - SCP functions:** Connects to the Content preparation functions. + - Content preparation functions:** Connects to the Content and metadata. + - Control:** Connects to the Content delivery functions. +- Service control functions (Yellow box):** + - IPTV service control functional block:** Connects to the Multicast delivery control protocol and the Service user profile functional block. + - Service user profile functional block:** Connects to the Content delivery functions. +- Content delivery functions (Orange box):** + - Content distribution and location control functions:** Connects to the Delivery protocols. + - Content delivery and storage functions:** Connects to the Delivery protocols and the Content and control. +- Network functions (Green box):** + - Authentication and configuration protocol:** Connects to the Authentication and IP allocation functional block. + - Authentication and IP allocation functional block:** Connects to the Access network functions. + - Resource control functional block:** Connects to the Core transport functions. + - Content and control:** Connects to the Transport functions. + - Transport functions:** Includes Access network functions, Edge functions, and Core transport functions. +- Management functions (Grey box):** + - Application management functional block:** Connects to the Content and metadata. + - Service control management functional block:** Connects to the Content and metadata. + - Control delivery management functional block:** Connects to the Content and metadata. + - End-user device management functional block:** Connects to the Content and metadata. + - Transport management functional block:** Connects to the Content and metadata. +- Content provider functions (Dark Grey box):** + - Content and metadata sources:** Connects to the Content and metadata. + +IPTV architectural overview diagram showing four main functional areas: End-user functions, Application functions, Service control functions, and Network functions, along with Management and Content provider functions. + +Y.1903(14)\_F02 + +Figure 2 – IPTV architectural overview [ITU-T Y.1910] + +Considering the generic IPTV architecture shown in Figure 2, the mobile IPTV end user can be connected to IPTV service providers using the mobile network interfaces through mobile access network functions of mobile IPTV TD. Most of the architectural components of mobile IPTV are the same as fixed IPTV, but it is required to have wireless connectivity between the terminal device and network provider. The impact of mobile IPTV on the architectural components of IPTV is shown in Figure 3. + +![Figure 3: The impact of mobile IPTV on the IPTV architectural components. The diagram shows two main blocks. On the left, a red box labeled 'End-user functions of mobile IPTV' contains two sub-blocks: 'Mobile IPTV terminal functions' and 'Mobile access network functions'. On the right, a larger grey box labeled 'Network functions' contains a purple box 'Resource control functional block' and a green box 'Mobile access network functions'. The green box is labeled 'Transport functions' below it. An orange lightning bolt connects the 'Mobile access network functions' block in the red box to the 'Mobile access network functions' block in the green box. Ellipses (...) are shown next to the 'Resource control functional block' and the 'Mobile access network functions' block in the grey box. The text 'Y.1903(14)_F03' is at the bottom right of the diagram.](4e4be0bd8b235167902f2c03e41da651_img.jpg) + +Figure 3: The impact of mobile IPTV on the IPTV architectural components. The diagram shows two main blocks. On the left, a red box labeled 'End-user functions of mobile IPTV' contains two sub-blocks: 'Mobile IPTV terminal functions' and 'Mobile access network functions'. On the right, a larger grey box labeled 'Network functions' contains a purple box 'Resource control functional block' and a green box 'Mobile access network functions'. The green box is labeled 'Transport functions' below it. An orange lightning bolt connects the 'Mobile access network functions' block in the red box to the 'Mobile access network functions' block in the green box. Ellipses (...) are shown next to the 'Resource control functional block' and the 'Mobile access network functions' block in the grey box. The text 'Y.1903(14)\_F03' is at the bottom right of the diagram. + +**Figure 3 – The impact of mobile IPTV on the IPTV architectural components** + +Figure 3 shows that mobile IPTV terminal functions are connected to the transport functions of a network provider through mobile access network functions. All other functions and functional blocks of the IPTV architecture can be re-used to provide mobile IPTV service, however, some extensions for support of the mobile network environment and the mobility aspects of a mobile IPTV TD may need to be considered for those functions and functional blocks. + +One of the key features of mobile IPTV is that it must be able to communicate and access the IPTV services irrespective of changes of the location or technical environment, such as various mobile access networks. These changes in the physical location and technical environment of mobile devices may derive differences in terms of network resources, network characteristics, network configurations, network policies, etc., among the home network and the visiting networks [b-ITU-T Q.1706]. Those differences may impact the QoS of the accessed IPTV services so that the configurations and operations of the IPTV functions need to adapt to the location and environment changes. + +## 6.2 Technical issues of mobile IPTV + +In order to describe the adaptation on the configurations and operations of IPTV functions, this Recommendation provides the functional requirements of mobile IPTV to provide continuous IPTV services even if the mobile IPTV TD moves to different locations and/or technical environments. + +The main technical issues of mobile IPTV are categorized as follows: + +- Service continuity support for terminal mobility: As an end-user IPTV TD moves to different locations, it should be expected to support the continuity of the ongoing IPTV service in the visited network to minimize the impact on QoS or QoE. +- QoS support for transport over mobile networks: Because the network resources of mobile networks are mostly shared and limited, it should be considered to provide appropriate mechanisms to support QoS in the mobile networks. +- Adaptability to dynamic resource changes in the mobile networks: Mobile IPTV TDs receive IPTV content via mobile networks. Because the network resources and states are highly dynamic as the terminal device moves, it should be considered to adapt the mobile IPTV service to the changes of resources to meet the QoS requirements and optimize the resource usage of the mobile networks. + +- Heterogeneity and portability support of IPTV terminal devices: Mobile IPTV TDs are heterogeneous and portable so that it should be considered to support diverse capabilities and lightweight functions of terminal devices. + +# **7 Functional requirements of mobile IPTV** + +## **7.1 General requirements of mobile IPTV** + +[ITU-T Y.1901] describes IPTV requirements in various aspects. The following requirements extracted from [ITU-T Y.1901] are applicable as general requirements for mobile IPTV. + +- R 6.4.3-01: The IPTV architecture is required to support mechanisms for exchanging subscriber-related information between the visited network (where the end user accesses the IPTV services) and the home IPTV service provider (where the end user has its subscription to the IPTV services) in case mobility is supported. +- R 6.4.3-02: The IPTV architecture is required to support mechanisms for discovering and selecting the end-user's service profile from the IPTV terminal device or the home service provider that will be used by the end user whenever it accesses such IPTV services from a visited network in case mobility is supported. +- R 6.4.3-03: The IPTV architecture is required to support mechanisms for discovering and selecting IPTV services provided by the home IPTV service provider for roaming users in case mobility is supported. +- R 6.4.3-04: The IPTV architecture is required to support capturing relevant control context information from the originating terminal device, and transferring them to the target terminal device in case mobility is supported. +- R 6.4.3-05: IPTV architecture is required to support nomadism for both personal mobility and terminal mobility. + +NOTE – Further information concerning nomadism, personal mobility and terminal mobility can be found in [ITU-T Y.2201]. + +- RR 6.1.1-01: The IPTV architecture is recommended to allow seamless IPTV service provision and operation across different networks supporting IPTV services. +- RR 6.1.4-03: The IPTV architecture is recommended to support capabilities for end-user mobility allowing access to IPTV services by the end user either in motion or not. +- RR 6.4-03: The IPTV architecture is recommended to support the ability to identify wireless network characteristics information sent by the IPTV terminal device. +- RR 6.4.1-02: The IPTV architecture is recommended to allow the delivery of IPTV services over different access networks (e.g., cable, optical, xDSL, wireless). +- RR 6.4.3-01: Where support for terminal mobility with service continuity exists, such support is also recommended for IPTV. + +## **7.2 Functional requirements of service aspects** + +- The IPTV architecture is recommended to use codecs, which are robust to packet losses, in order to maintain the minimum quality that is defined by QoS in case of some loss of multimedia data. +- The IPTV architecture is recommended to provide mechanisms to adapt the level of error protection in real time according to the related QoS parameters. +- The IPTV architecture is recommended to provide mechanisms to negotiate a media-coding scheme between the terminal device and IPTV service provider to select an appropriate coding scheme according to the terminal capability and wireless network characteristics. + +- The IPTV architecture is recommended to use scalable video coding schemes in content delivery. +- NOTE – The scalable video coding schemes such as H.264/AVC provide on-time adaptation to abrupt changes in the available bandwidths of mobile networks during handover. + +## 7.3 Functional requirements of networking aspects + +![Figure 4: An example architectural diagram concerning mobile access network operation for mobile IPTV. The diagram shows a Service controller (Service provider) at the top, connected to three Service channels (A, B, C) which lead to a Content server (Service provider). Below the service controller are two Gateways (Network provider). These gateways connect to three Mobile networks (Service regions X, Y, Z). Each mobile network is represented by a cluster of hexagonal cells. Mobile IPTV TDs (Terminals) are shown within these cells. Arrows indicate the flow of data from the content server through the service channels and gateways to the mobile networks and terminals. A label 'Y.1903(14)_F04' is present in the bottom right corner of the diagram area.](724c7777b608e53be38b12b6fb3c43bc_img.jpg) + +Figure 4: An example architectural diagram concerning mobile access network operation for mobile IPTV. The diagram shows a Service controller (Service provider) at the top, connected to three Service channels (A, B, C) which lead to a Content server (Service provider). Below the service controller are two Gateways (Network provider). These gateways connect to three Mobile networks (Service regions X, Y, Z). Each mobile network is represented by a cluster of hexagonal cells. Mobile IPTV TDs (Terminals) are shown within these cells. Arrows indicate the flow of data from the content server through the service channels and gateways to the mobile networks and terminals. A label 'Y.1903(14)\_F04' is present in the bottom right corner of the diagram area. + +**Figure 4 – An example architectural diagram concerning mobile access network operation for mobile IPTV** + +Figure 4 shows an example architectural diagram concerning mobile access network operation for mobile IPTV services. In Figure 4, the IPTV service controller is used by the IPTV service provider to manage and control the IPTV service. The gateways are used by the network provider to manage the service regions and to control mobile network facilities, such as base stations, for provision of the required QoS to mobile IPTV TDs. + +The mobile access network consists of cells (represented as hexagons in Figure 4) covered by a single base station. The cells can be grouped as service regions, with each service region including more than one base station (BS). As an example, the mobile access network of Figure 4 consists of six different service regions. + +The IPTV service controller chooses some base station(s) to create each service region based on the location information of mobile terminals and base stations, as well as based on the available resources of the mobile access network for the provision of the mobile IPTV service. A service region can be created, updated and removed by the IPTV service controller in collaboration with the related gateway. A service region can be differentiated as a broadcast service region and multicast + +service region, according to the content delivery mechanisms used in the service region. Within each service region, IPTV contents are delivered to the mobile IPTV TDs using various delivery mechanisms such as unicast, broadcast and multicast technologies. + +The relevant information for joining a specific multicast/broadcast channel to enjoy IPTV contents needs to be provided to the mobile IPTV TD using an appropriate procedure. The mobile IPTV TD can move within a service region and it can also move to neighbouring service regions. There is no service discontinuity due to the handover of mobile IPTV TD within the same service region because radio resources with the same characteristics are allocated to each base station, belonging to the same service region. Service discontinuity may take place when the mobile IPTV TD crosses the boundary of different service regions. The allocation of radio resources for a service region is managed by the IPTV service controller and enforced by the gateway to provide the required QoS to mobile IPTV TDs. In general, the use of multicast and broadcast technologies is very useful due to scarcity of radio resources in the mobile network environments. + +Considering this example architectural diagram concerning mobile access network operation for mobile IPTV services, the following requirements for provision of the mobile IPTV service using multicast/broadcast technologies are specified: + +- The IPTV architecture is required to support broadcast and multicast capabilities for efficient use of radio resources in the mobile access network. + +NOTE 1 – Multicast and broadcast technologies that can be used include multicast and broadcast service (MBS) by IEEE [b-IEEE 802.16m], multimedia broadcast and multicast service (MBMS) by 3GPP [b-3GPP-TS23.246] and multicast and broadcast service (MCBCS) by mobile WiMAX forum [b-WMF-T23], etc. + +- The IPTV architecture is required to be capable of managing service regions for the mobile IPTV service. + +NOTE 2 – Managing operations include group management and session management for the multicast/broadcast channel, and management of IPTV contents for each service region. + +- The IPTV architecture is required to be capable of selecting BSs (or APs) to create a specific service region for the mobile IPTV service. +- The IPTV architecture is required to be capable of changing a service region by newly adding/excluding one or more BSs (or APs) to/from an existing service region for the mobile IPTV service. + +NOTE 3 – The service region can be reconfigured, for example, when 1) a mobile IPTV TD moves to a new BS (or AP) in the middle of receiving IPTV content, or 2) a mobile IPTV TD has turned off its power and as a consequence there is no more IPTV content to be delivered to the associated BS (or AP). + +- The IPTV architecture is required to be capable of distributing physical multicast/broadcast channel information of the mobile IPTV services associated with the service region. +- The IPTV architecture is required to be capable of transmitting the IPTV service information via all of the BSs and APs forming the service region for the mobile IPTV service. +- The IPTV architecture is required to be capable of selecting those BSs (or APs) which participate in transmitting IPTV service traffic to the mobile IPTV TDs among the BSs (or APs) forming a single service region for the mobile IPTV service. + +NOTE 4 – A service region can be reconfigured with BSs (or APs) where mobile IPTV TDs exist in that area, for the efficient use of radio resources. + +- The IPTV architecture is required to support the mobile IPTV service regardless of power management of mobile IPTV TD. + +NOTE 5 – Even if the communication status between a specific mobile IPTV TD and a BS (or AP) is idle or in sleep mode, the IPTV service needs to be provided continuously for other mobile IPTV TDs in that service region. + +- The IPTV architecture is recommended to support multicarrier operations to increase the data rate. +- The IPTV architecture is required to be capable to choose a limited number of IPTV services from all available IPTV services for a specific multicast/broadcast channel, considering the resource limitations of the mobile network. +- The IPTV architecture is required to support mapping between content identifiers provided by the IPTV service provider and channel identifiers provided by the mobile network provider. +- The IPTV architecture is recommended to be capable of simultaneously transmitting the same IPTV content using different transmission modes such as multicast, broadcast and unicast in the mobile network. + +NOTE 6 – For example, the same IPTV content may be provided via multiple video resolutions (e.g., SVC): high resolution video is transmitted to specific high-quality terminal devices in unicast mode, and low resolution video is transmitted to multiple low-quality terminal devices in multicast/broadcast mode. + +- The IPTV architecture is required to be capable of switching between multicast/broadcast and unicast transmission modes. + +NOTE 7 – A terminal device selects the IPTV content in unicast mode first; as more terminal devices select the same IPTV content, the IPTV architecture switches from unicast mode to multicast/broadcast mode to deliver that IPTV content. When only one terminal device receives the IPTV content in multicast/broadcast mode, the IPTV architecture switches again from multicast/broadcast mode to unicast mode. If there is no spare broadcast/multicast channel, the IPTV architecture uses the unicast mode. + +- The IPTV architecture is required to support synchronization of broadcast contents in the same multicast/broadcast service region. +- The IPTV architecture is required to support seamless handover between APs (or BSs) within the same multicast/broadcast service region. +- The IPTV architecture is recommended to support robustness in IPTV content delivery where high packet loss and error rates occur in the mobile network. +- The IPTV architecture is recommended to use congestion control and/or flow control functions for the efficient delivery of the mobile IPTV service when the network conditions change. +- The IPTV architecture can optionally support multiple mobile network connectivity. +- The IPTV architecture is recommended to support synchronization and merging of the content from multiple mobile network interfaces of an IPTV TD. +- The IPTV architecture is recommended to support N-screen services [b-ITU-T Y-Sup.24] among mobile IPTV TDs, which may be connected to different access networks. +- The IPTV architecture is recommended to support terminal mobility with service continuity in the case of supporting the mobile IPTV service. +- The IPTV architecture is recommended to support seamless mobile IPTV service provision and operation across different service regions. +- The IPTV architecture is required to be capable of monitoring the status of the mobile IPTV TD in a given service region. +- The IPTV architecture is recommended to be capable of collecting and managing the channel usage information of BSs (or APs) in a given service region. + +- The IPTV architecture is recommended to be capable of collecting and managing the user's environmental information. +NOTE 8 – The user's environmental information includes the current user's connected link state, location, status of the terminal device and channel usage information. +- The IPTV architecture is required to be capable of determining whether there is any mobile IPTV TD which uses the multicast/broadcast channel allocated to a specific BS (or AP) in a service region. + +## **7.4 Functional requirements of QoS and QoE aspects** + +- The IPTV architecture is required to be capable of providing error control and radio resource management based on QoS/QoE requirements for mobile IPTV. +- The IPTV architecture is required to be capable of providing a resource allocation function in the access network to decide its availability between the subscriber terminal and base station. +- The IPTV architecture is required to free allotted resources such as the wireless channel and radio bandwidth in case of unicast when a session ends. Freed resources of the mobile network can be used for QoS enhancement in another mobile IPTV TD. +- The IPTV architecture is required to be capable of measuring the QoS between BS (or AP) and mobile IPTV TD necessary to support the required QoE of the mobile IPTV service. +- The IPTV architecture is required to be capable of supporting resource allocation and negotiation in the mobile network according to location changes of the mobile IPTV TD. +- The IPTV architecture is recommended to be capable of supporting mechanisms to inform service providers of the characteristics of the mobile network (e.g., available bandwidth, bit error rate, signal-to-noise ratio). +- The IPTV architecture is required to be capable of allocating radio resources for a specific service region associated with the mobile IPTV service. +- The IPTV architecture is required to be capable of managing the priority of traffic scheduling associated with the mobile IPTV service. +- The IPTV architecture is required to be capable of reconfiguring the service region according to the quality of the multicast/broadcast channel to maintain the required QoS/QoE of the mobile IPTV service. +- The IPTV architecture is required to be capable of releasing and reusing the radio resources which are dedicated to a specific mobile IPTV service, if and when those dedicated radio resources are not used any more. + +NOTE 1 – Recommendation ITU-T G.1080 "Quality of experience requirements for IPTV services" [b-ITU-T G.1080] can be applied for mobile IPTV (the QoE requirements of ITU-T G.1080 are defined from an end-user perspective and are agnostic to network deployment architectures and transport protocols). + +NOTE 2 – Recommendation ITU-T G.1082 "Measurement-based methods for improving the robustness of IPTV performance" [b-ITU-T G.1082] can be considered concerning solutions to provide QoS for mobile IPTV. + +## **7.5 Functional requirements of mobile IPTV terminal device aspects** + +The following requirements of mobile IPTV terminal devices are related to their usage by an IPTV-enabled mobile network. + +NOTE – As far as general requirements of mobile IPTV terminal devices, these are outside the scope of this Recommendation. + +- The mobile IPTV TD is required to receive and process the IPTV contents transmitted over the multicast/broadcast channel in the mobile network. + +- The mobile IPTV TD is required to be able to select specific network interfaces among the available mobile network interfaces. +- The mobile IPTV TD is required to be capable of identifying the service region to which it is currently associated. +- The mobile IPTV TD is required to be capable of measuring the quality of radio resources for the purpose of providing the mobile IPTV service. +- The mobile IPTV TD is required to be capable of informing the service provider or network provider about the measured quality information which is used to reconfigure the service region for the mobile IPTV service. +- The mobile IPTV TD is required to be capable of measuring the performance characteristics of the mobile network between the BS (or AP) and mobile IPTV TD, and to be capable of informing the BS (or AP). +- The IPTV terminal device is required to be able to select and receive IPTV contents through the service region that is set up for that mobile IPTV TD. + +# **8 Security considerations** + +As far as the security requirements of mobile IPTV are concerned, the requirements contained in [ITU-T X.1191] are applicable. Also, [ITU-T X.1196] may be considered depending on specific mobile IPTV service deployments. + +# Bibliography + +- [b-ITU-T G.1080] Recommendation ITU-T G.1080 (2008), *Quality of experience requirements for IPTV services*. +- [b-ITU-T G.1082] Recommendation ITU-T G.1082 (2009), *Measurement-based methods for improving the robustness of IPTV performance*. +- [b-ITU-T G.9959] Recommendation ITU-T G.9959 (2012), *Short range narrow-band digital radiocommunication transceivers – PHY and MAC layer specifications*. +- [b-ITU-T H.264] Recommendation ITU-T H.264 (2014), *Advanced video coding for generic audiovisual services*. +- [b-ITU-T H.510] Recommendation ITU-T H.510 (2002), *Mobility for H.323 multimedia systems and services*. +- [b-ITU-T H.701] Recommendation ITU-T H.701 (2009), *Content delivery error recovery for IPTV services*. +- [b-ITU-T H.720] Recommendation ITU-T H.720 (2008), *Overview of IPTV terminal devices and end systems*. +- [b-ITU-T Q.1706] Recommendation ITU-T Q.1706 (2006), *Mobility management requirements for NGN*. +- [b-ITU-T Q.1761] Recommendation ITU-T Q.1761 (2004), *Principles and requirements for convergence of fixed and existing IMT-2000 systems*. +- [b-ITU-T Y.1902] Recommendation ITU-T Y.1902 (2011), *Framework for multicast-based IPTV content delivery*. +- [b-ITU-T Y.2001] Recommendation ITU-T Y.2001 (2004), *General overview of NGN*. +- [b-ITU-T Y.2091] Recommendation ITU-T Y.2091 (2011), *Terms and definitions for next generation networks*. +- [b-ITU-T Y-Sup.24] ITU-T Y-series Recommendations – Supplement 24 (2013), *ITU-T Y.2000-series – Supplement on N-screen service scenarios for fixed mobile convergence*. +- [b-IEEE 802.16m] IEEE 802.16m-2011, *IEEE Standard for Local and metropolitan area networks – Part 16: Air Interface for Broadband Wireless Access Systems – Amendment 3: Advanced Air Interface*. +<> +- [b-WMF-T23] WiMAX Forum (2009), *WiMAX Forum Mobile System Profile Specification*. WMF-T23-001-R015v01. +<[http://www.wimaxforum.org/imt-2000/9/WMF-T23-001-R015v01\\_MSP-Common-Part.pdf](http://www.wimaxforum.org/imt-2000/9/WMF-T23-001-R015v01_MSP-Common-Part.pdf)> +- [b-3GPP TS 23.246] 3GPP TS 23.246 (2012) *Technical Specification Group Services and System Aspects; Multimedia Broadcast/Multicast Service (MBMS); Architecture and functional description Release 11*. +<> + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|--------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Terminals and subjective and objective assessment methods | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/08ccf644bfe3417a310e15f03a536ff8_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/08ccf644bfe3417a310e15f03a536ff8_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..7b81f50a11565104f0069ce4846b74ae53df4975 --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/08ccf644bfe3417a310e15f03a536ff8_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:0dc7f899220082a7d9935143b81619e665e847b24b19fc1cdb0f1403bc3ac0cc +size 105912 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/0b7849dae424b0dd33e6386d2384643a_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/0b7849dae424b0dd33e6386d2384643a_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..41ee792358fd50e16ab4e1ed427d4b8df8ebf722 --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/0b7849dae424b0dd33e6386d2384643a_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:90977cce0df1bf6fea3b2360b186a1f3ee64333578dcb21564a29b254b759507 +size 318082 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/11edb7fcedf09ac6a817f8d7b8c61eec_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/11edb7fcedf09ac6a817f8d7b8c61eec_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..b457e038438dde263e17919885a310f75a114db4 --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/11edb7fcedf09ac6a817f8d7b8c61eec_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:5bd6747c9af0183a7784f799f2e5aecb32ef2907e12efce650dfddba6725d594 +size 284083 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/1b23b78336d8bd286c653cbdb38428dd_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/1b23b78336d8bd286c653cbdb38428dd_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..5a3272ecd6aa7af153c796d045781313e7d8c257 --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/1b23b78336d8bd286c653cbdb38428dd_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:7abe7b776dfdcb673be34200086091a5c7c92a30b3eedfb95a7cea3b204c6ba7 +size 253652 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/2f587210e4f97c32758c5972e2e83d20_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/2f587210e4f97c32758c5972e2e83d20_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..8fd6fb2c4c083446cbc1cc1689f30f0954abcb63 --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/2f587210e4f97c32758c5972e2e83d20_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:d624fa5c3172af8610cd5f86c98a1d0ffa375ccd101106277f7c8c6337940da8 +size 130080 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/3493d7ba4c86f944e159de1bf45ff03d_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/3493d7ba4c86f944e159de1bf45ff03d_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..2c4ea97497ef7be70da6e9462336c27daff8d6f1 --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/3493d7ba4c86f944e159de1bf45ff03d_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:08274053e91405cff5ba42e47e3c8184c338c270eb765929c7a19c866b5a883b +size 150376 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/352d21d1e740e4a58cb17ab8656cfad8_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/352d21d1e740e4a58cb17ab8656cfad8_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..3590da475536df8f78d1de429aac636cb05e36dd --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/352d21d1e740e4a58cb17ab8656cfad8_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:8435f21465812143ee0b3e459ef5746639a890c12ce0c974b29fc2bedd0113e6 +size 75578 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..d56ea12835051ae0d2bd8318e0074f2662685ecc --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:ad03bac0c412039287686e1ce9fbb8d9ad689fb7086d09e2a6c0eea60e067ff4 +size 148726 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/50ef8602c7c9edd2da0e2133e772c2a2_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/50ef8602c7c9edd2da0e2133e772c2a2_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..6269b99a1f34b610f19359fbca8068730c5ead93 --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/50ef8602c7c9edd2da0e2133e772c2a2_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:2f2ed2e3cfea72f455a332b9bd8e52955ff3d2dee370331a4c61f96fb15e4c44 +size 118946 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/6629e8a87e7552e2454b7c3e9f6d73a0_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/6629e8a87e7552e2454b7c3e9f6d73a0_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..f35643c8914f6104e6ce3036b354b4a699622e16 --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/6629e8a87e7552e2454b7c3e9f6d73a0_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:b9ea4ea5bc739d69da93e80574c8265559cf3d5d327cd3ac48e223c2ead99330 +size 85554 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/7133ccf78043568ca62ecbcd43628a4a_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/7133ccf78043568ca62ecbcd43628a4a_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..b6bfc994b049d3268ec0c2651df96354a3dc97ec --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/7133ccf78043568ca62ecbcd43628a4a_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:e6e1571062e84de3de6b3ce8e432f36156a309e1882c496f7496f188d6178969 +size 275448 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/77959075c823bb5169480d7b8ff82a63_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/77959075c823bb5169480d7b8ff82a63_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..8bee99cd99d4e7f713ca0e5f58a87ec57fafc794 --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/77959075c823bb5169480d7b8ff82a63_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:00e019a1b14baefd8d61b53b8cf121a2366dd628004d1d7cb4e218a417afe06b +size 228473 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/798679874d1c29f8343506a156c79d7e_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/798679874d1c29f8343506a156c79d7e_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..0ef337424205233e84dab2becb516d77b1d13f91 --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/798679874d1c29f8343506a156c79d7e_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:37c993cc9a6d01ed83b356c3fb54aa6d2dbf3ded53388a524e4f0b664facf447 +size 325580 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/7b7596fb5ef925025341a9aacb6f2be7_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/7b7596fb5ef925025341a9aacb6f2be7_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..59ca392f548173ccac5a37023551499d292afed0 --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/7b7596fb5ef925025341a9aacb6f2be7_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:bbf1941fe2c6136e3322964a74accca4576faf6c73ed4a7938cca15dc8c211fa +size 283051 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/811d62d08ce934a2a7e5bd877abff7ad_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/811d62d08ce934a2a7e5bd877abff7ad_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..594e250f269c530c537a36ab24f4fd3305919b37 --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/811d62d08ce934a2a7e5bd877abff7ad_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:5a40b3eaed3e905e38d1f2811376784361d62ca979d2c89c58eed65398b28476 +size 226769 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..cd0ba943f1695e64b724ba2b0b86c40c0422ae1a --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:73c7056b7c804bddd7ec35f726212ee332aafddb90ac4775c5b890b23b579069 +size 6753 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/8c3eb53c927f55acd19723cfcd0c43b6_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/8c3eb53c927f55acd19723cfcd0c43b6_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..17458fe23c3861695ba2f568d9b327e10a5add0f --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/8c3eb53c927f55acd19723cfcd0c43b6_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:d34f84a16cd34db3312038ef3f172cb9d365edac0ce9f81b26ca6f31f3c0920f +size 115938 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/8e14350b4b669119a3bdfca7869110ca_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/8e14350b4b669119a3bdfca7869110ca_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..a7bbc3e9e08cb25f3832156ccecc011962369925 --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/8e14350b4b669119a3bdfca7869110ca_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:1f9c31e88fb311a9892fb8d7d844953bbc6717a59978bbbd2ef83d2b7226ba5c +size 4870 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/99698c448635861b7dc8d352f87a1b2b_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/99698c448635861b7dc8d352f87a1b2b_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..0c03aa1eb2ae0d0254e56e70228c9af98a2cc76e --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/99698c448635861b7dc8d352f87a1b2b_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:6d2d20ddb165630914bb1a250ed1c7fe6104738ca877d3913648857a9c591f8c +size 242265 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/9a5927586a691c4908aa2cf98bd47ebb_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/9a5927586a691c4908aa2cf98bd47ebb_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..857c87228563f6bb012a39e8e4ab6b99c1c061a5 --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/9a5927586a691c4908aa2cf98bd47ebb_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:aeceb8084c09652859194b5904f1645701807f846d379cd0bbbbd6bedd9ac045 +size 309813 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/9d49325b5cb2d7a1431cb30637b5a7c9_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/9d49325b5cb2d7a1431cb30637b5a7c9_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..8fceb53cadb2d1eadaa255854ee2ba73b8e97845 --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/9d49325b5cb2d7a1431cb30637b5a7c9_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:4bef593f6a3401fa37e9232ee150e18587b7ae3fb2f400f8bdc2059972d99f35 +size 91510 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/aaf3e6e44cdeabd6d1df869c5f392ea1_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/aaf3e6e44cdeabd6d1df869c5f392ea1_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..48d7400ad6fac98b08091f44b3fd2a74fb7062d6 --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/aaf3e6e44cdeabd6d1df869c5f392ea1_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:67b07ae1a9a76ad3a63952702cde546461a8b25aa6ef0b389c466d225acc27a1 +size 274480 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/af6c3f383ddc0c142cdd7e186cc78199_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/af6c3f383ddc0c142cdd7e186cc78199_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..02357947000d19ef9eb0ae038f940150243a9f4d --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/af6c3f383ddc0c142cdd7e186cc78199_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:eb5adcd09ff73d81bb92091cffcf2476dff5486ab3b7669a37828a2460d0e724 +size 240122 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/b20942bb14022381a243971ab9790dd9_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/b20942bb14022381a243971ab9790dd9_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..0b6c1e597cb86b4eac201311d9e71d47366da1c0 --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/b20942bb14022381a243971ab9790dd9_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:6f471c4f2cdccf0b08a08c750256344ebb9b3ea96014cc7e459beb2444a20f61 +size 237912 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/b3335932702b8668e62791e9fd12c9ff_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/b3335932702b8668e62791e9fd12c9ff_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..11d305e9c70811d15954a25a22fd63554b43aff9 --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/b3335932702b8668e62791e9fd12c9ff_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:474824c7c41cf96411e590df99a3bf1ba8ced1b0c586219eff34debaede0ee75 +size 285529 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/b68ed2f7c90787b2fcfeb6be5640ecd4_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/b68ed2f7c90787b2fcfeb6be5640ecd4_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..740d7ff436d088689bced864ac42e5f9644ba0a4 --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/b68ed2f7c90787b2fcfeb6be5640ecd4_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:fb4c7bc78e3aa3c100f89eec314430bbc44645e1a28481c18de0a7f19819249b +size 164241 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/c0b9e5fc63e19306394e0d4249da62cd_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/c0b9e5fc63e19306394e0d4249da62cd_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..5fe38cd98af7b36e166511966436337d5cb8c640 --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/c0b9e5fc63e19306394e0d4249da62cd_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:99a5c0c571db286483767f3d0c95393571c12bf91f6aeafd49cce3fab59c77f8 +size 164540 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/c2c4e63ebb9afc1ab64e39a159890e0f_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/c2c4e63ebb9afc1ab64e39a159890e0f_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..3e9ba0520a4f7a8f67e40e44c575f6dc304fe745 --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/c2c4e63ebb9afc1ab64e39a159890e0f_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:8c383cef74dfc36a79c91b98caef08751b4ff13885d8eb4f10e5a411143a49ed +size 131718 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/c3fcdb9e14cb1f7e5e0232c5fe0c5198_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/c3fcdb9e14cb1f7e5e0232c5fe0c5198_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..3a900c02403ff996f744a20430291bdded38f36c --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/c3fcdb9e14cb1f7e5e0232c5fe0c5198_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:907a30bfb8e82c3015213303c805ee228c9714f77ae19febc3f4f913af7c467c +size 150944 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/c914f51f4427bc672dd0526cfc90ebe9_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/c914f51f4427bc672dd0526cfc90ebe9_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..a28600bc2e1f9968982db62cafc16a2f8e89935b --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/c914f51f4427bc672dd0526cfc90ebe9_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:7bf62be433785319c0c508fcb4a29106cc5004129fc3ca851d1c723da1f38771 +size 252164 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/ca86f53f9735fe98b6c6003d1b759f64_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/ca86f53f9735fe98b6c6003d1b759f64_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..ee9c395ea5ac6960c6cd49d63a55cbcee66ec806 --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/ca86f53f9735fe98b6c6003d1b759f64_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:99bda22e0ed75a066ad2013dede17dde4bedc839925f047accec75f4c73d2169 +size 262624 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/d26959f4514c26ca19c3d6f00da85956_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/d26959f4514c26ca19c3d6f00da85956_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..e0d8c09bb752ef4d3bf0de777f30575d3a032516 --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/d26959f4514c26ca19c3d6f00da85956_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:3a7d77f05234aa8576fc355a50d0f84d6b1458bb8ddcf2b9ad04610897ca43c4 +size 4192 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..cea684790392d57637b109b6bf0912026fd0f32a --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:cb2866b3ec0c3093ac693a40a1376e32cf55e0ec398732aea38d1066119d2b63 +size 39237 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/e8f5117fb031f413a836525061addd61_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/e8f5117fb031f413a836525061addd61_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..624b5bdd11b0cb9b9e85dc91510794f63e6f18ef --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/e8f5117fb031f413a836525061addd61_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:64f45426e9fd137e17985735ea0ae74e51c7948762396ad1bbb0b8d13a50fd2c +size 222696 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/e9314c83043183351ed74908e9bf2f90_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/e9314c83043183351ed74908e9bf2f90_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..ad604880be69419a5017aa152d68acf6c99742ba --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/e9314c83043183351ed74908e9bf2f90_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:54b81e49aded84d3b63e2abce907e517a7876e1b96cbf622f2949641c70d41f8 +size 3488 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/f78d2e126f00fcc5d8d9797ca410cc09_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/f78d2e126f00fcc5d8d9797ca410cc09_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..be72b0ab53a07ec058eeaed6211a66684ed486e0 --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/f78d2e126f00fcc5d8d9797ca410cc09_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:7aa9f66ee6ee4e3f782cc50a4465f775a3c654a2593f12bbde7af91181b60eab +size 133915 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/fa859e4e468bfb2710a94527f2c504af_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/fa859e4e468bfb2710a94527f2c504af_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..1e3b0a192d2a73f9a82c2afcbba3673397f9b8b9 --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/fa859e4e468bfb2710a94527f2c504af_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:e49d9fe5fc1defd738eb2a01940278c748f03b56217c697149afc5e1695446f5 +size 252117 diff --git a/marked/Y/T-REC-Y.1910-200809-I_PDF-E/fed4a04822c24fb22cca3a14f4ddae83_img.jpg b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/fed4a04822c24fb22cca3a14f4ddae83_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..b1531a75f12028af79b433c87ecf9e22ef9e9342 --- /dev/null +++ b/marked/Y/T-REC-Y.1910-200809-I_PDF-E/fed4a04822c24fb22cca3a14f4ddae83_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:32029407a124d51c1adf9ba77340bfc50f5082d9db75abc65d0c37415277a507 +size 83325 diff --git a/marked/Y/T-REC-Y.1920-201207-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg b/marked/Y/T-REC-Y.1920-201207-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..2d8bbe6c90810e8d505635be14df5a79dc57b0f2 --- /dev/null +++ b/marked/Y/T-REC-Y.1920-201207-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:987a2dd33cdb1acad60bd7595ccd33499b2a5daa54e3a8c51a60ff5f2915fff5 +size 59756 diff --git a/marked/Y/T-REC-Y.1920-201207-I_PDF-E/474a819357587e34949a3e110ff19b30_img.jpg b/marked/Y/T-REC-Y.1920-201207-I_PDF-E/474a819357587e34949a3e110ff19b30_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..57796fea86bf9ad35a5d68bedf56cca9b498a1a2 --- /dev/null +++ b/marked/Y/T-REC-Y.1920-201207-I_PDF-E/474a819357587e34949a3e110ff19b30_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:9671e568ce94dd064361f28f26e18189e4b5030daa81f46076e7480323131609 +size 16365 diff --git a/marked/Y/T-REC-Y.1920-201207-I_PDF-E/58f4167687de8d7339594e5f6fbe0bc6_img.jpg b/marked/Y/T-REC-Y.1920-201207-I_PDF-E/58f4167687de8d7339594e5f6fbe0bc6_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..64691f15243ec49568ecf13ce5024459fe9fd6f6 --- /dev/null +++ b/marked/Y/T-REC-Y.1920-201207-I_PDF-E/58f4167687de8d7339594e5f6fbe0bc6_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:55661ede69dba2a12a22c7b9e374c1d8919e624da438a652ba941460573215fe +size 168893 diff --git a/marked/Y/T-REC-Y.1920-201207-I_PDF-E/7133ccf78043568ca62ecbcd43628a4a_img.jpg b/marked/Y/T-REC-Y.1920-201207-I_PDF-E/7133ccf78043568ca62ecbcd43628a4a_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..d9506bf5bd0fbb304a757cda76a1b9718cd2fa90 --- /dev/null +++ b/marked/Y/T-REC-Y.1920-201207-I_PDF-E/7133ccf78043568ca62ecbcd43628a4a_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:5303b68725464a1dac968d35e5d1ee071af0cc0abbf13e291af37383de0f3271 +size 64280 diff --git a/marked/Y/T-REC-Y.1920-201207-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg b/marked/Y/T-REC-Y.1920-201207-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..83de44cfa91ff96cd6d044185230bbdca1aff85e --- /dev/null +++ b/marked/Y/T-REC-Y.1920-201207-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:92c3c68bcdb95caa413d3d9a4747655489556a99ef57b3def4ad289d99ef7337 +size 6615 diff --git a/marked/Y/T-REC-Y.1920-201207-I_PDF-E/c85ded401105f62f2d6ff26b3b5eb4af_img.jpg b/marked/Y/T-REC-Y.1920-201207-I_PDF-E/c85ded401105f62f2d6ff26b3b5eb4af_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..183fbd63b2a65c1a5a7cd1135869980f9a92a24e --- /dev/null +++ b/marked/Y/T-REC-Y.1920-201207-I_PDF-E/c85ded401105f62f2d6ff26b3b5eb4af_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:5eff8d5a10d5efba0a4b297bac336d2140fa5961d245acb4a035394bea660143 +size 177126 diff --git a/marked/Y/T-REC-Y.1920-201207-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg b/marked/Y/T-REC-Y.1920-201207-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..285916fd121139b89a413435a623114237924686 --- /dev/null +++ b/marked/Y/T-REC-Y.1920-201207-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:e166d17c785b315e422add176f7e8c442b25b649573b5084410aed148feb525a +size 83806 diff --git a/marked/Y/T-REC-Y.1920-201207-I_PDF-E/raw.md b/marked/Y/T-REC-Y.1920-201207-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..84b4860a464c87b2ae6fd39b32f1dac7793bef5d --- /dev/null +++ b/marked/Y/T-REC-Y.1920-201207-I_PDF-E/raw.md @@ -0,0 +1,807 @@ + + +I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +## Y.1920 + +(07/2012) + +SERIES Y: GLOBAL INFORMATION +INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS +AND NEXT-GENERATION NETWORKS + +Internet protocol aspects – IPTV over NGN + +# --- **Guidelines for the use of traffic management mechanisms in support of IPTV services** + +Recommendation ITU-T Y.1920 + +![ITU logo: A globe with red lightning bolts and the text 'ITU International Telecommunication Union'.](84a1d09fb489061482111515543b60dc_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with two red lightning bolts striking it. To the right of the globe, the text 'ITU' is written in a large, bold, blue font, and below it, the words 'International Telecommunication Union' are written in a smaller, blue font. + +ITU logo: A globe with red lightning bolts and the text 'ITU International Telecommunication Union'. + +# ITU-T Y-SERIES RECOMMENDATIONS **GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT- GENERATION NETWORKS** + +| | | +|--------------------------------------------------------------------|----------------------| +| GLOBAL INFORMATION INFRASTRUCTURE | | +| General | Y.100–Y.199 | +| Services, applications and middleware | Y.200–Y.299 | +| Network aspects | Y.300–Y.399 | +| Interfaces and protocols | Y.400–Y.499 | +| Numbering, addressing and naming | Y.500–Y.599 | +| Operation, administration and maintenance | Y.600–Y.699 | +| Security | Y.700–Y.799 | +| Performances | Y.800–Y.899 | +| INTERNET PROTOCOL ASPECTS | | +| General | Y.1000–Y.1099 | +| Services and applications | Y.1100–Y.1199 | +| Architecture, access, network capabilities and resource management | Y.1200–Y.1299 | +| Transport | Y.1300–Y.1399 | +| Interworking | Y.1400–Y.1499 | +| Quality of service and network performance | Y.1500–Y.1599 | +| Signalling | Y.1600–Y.1699 | +| Operation, administration and maintenance | Y.1700–Y.1799 | +| Charging | Y.1800–Y.1899 | +| IPTV over NGN | Y.1900–Y.1999 | +| NEXT GENERATION NETWORKS | | +| Frameworks and functional architecture models | Y.2000–Y.2099 | +| Quality of Service and performance | Y.2100–Y.2199 | +| Service aspects: Service capabilities and service architecture | Y.2200–Y.2249 | +| Service aspects: Interoperability of services and networks in NGN | Y.2250–Y.2299 | +| Numbering, naming and addressing | Y.2300–Y.2399 | +| Network management | Y.2400–Y.2499 | +| Network control architectures and protocols | Y.2500–Y.2599 | +| Packet-based Networks | Y.2600–Y.2699 | +| Security | Y.2700–Y.2799 | +| Generalized mobility | Y.2800–Y.2899 | +| Carrier grade open environment | Y.2900–Y.2999 | +| FUTURE NETWORKS | Y.3000–Y.3499 | +| CLOUD COMPUTING | Y.3500–Y.3999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +## **Recommendation ITU-T Y.1920** + +# **Guidelines for the use of traffic management mechanisms in support of IPTV services** + +## **Summary** + +Recommendation ITU-T Y.1920 describes a set of traffic management mechanisms which are aimed to facilitate the efficient support of IPTV services over the network infrastructure and provides guidelines on the use of the traffic management mechanisms in various IPTV services such as VoD and Live TV. + +## **History** + +| Edition | Recommendation | Approval | Study Group | +|---------|----------------|------------|-------------| +| 1.0 | ITU-T Y.1920 | 2012-07-29 | 13 | + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2013 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|-------------------------------------------------------------------------------------------------|-------------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Term defined elsewhere ..... | 1 | +| 3.2 Term defined in this Recommendation ..... | 2 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 3 | +| 6 Requirements ..... | 3 | +| 6.1 High-level requirements ..... | 3 | +| 6.2 Functional requirements ..... | 3 | +| 6.3 Mapping among high-level requirements, functional requirements and mechanisms ..... | 4 | +| 7 Traffic management mechanisms for control plane, data plane and management plane..... | 5 | +| 7.1 Control plane ..... | 6 | +| 7.2 Data plane..... | 8 | +| 7.3 Management plane..... | 10 | +| 8 Guidelines to use IPTV traffic management mechanisms..... | 10 | +| 8.1 Mapping of traffic management mechanisms to functions in IPTV functional architecture ..... | 11 | +| 8.2 Guidelines for the use of traffic management mechanisms for IPTV services ..... | 12 | +| 9 Security considerations..... | 13 | +| Appendix I – Discussion on ITU-T Y.1541 performance classes for IPTV..... | 14 | +| Appendix II – Traffic management for core network, access network and home network..... | 16 | +| II.1 Traffic management for the core network ..... | 16 | +| II.2 Traffic management for the access network..... | 18 | +| II.3 Traffic management for home network..... | 18 | +| Appendix III – Admission control example for IMS based architecture ..... | 20 | +| Appendix IV – An example of guidelines for management plane mechanisms..... | 21 | +| IV.1 Management plane..... | 21 | +| IV.2 Performance measurement and management ..... | 21 | +| IV.3 SLA..... | 21 | +| IV.4 Policy management ..... | 22 | +| Appendix V – Cross-layer interaction for IPTV services ..... | 23 | +| Bibliography..... | 24 | + + + +# Recommendation ITU-T Y.1920 + +# Guidelines for the use of traffic management mechanisms in support of IPTV services + +# 1 Scope + +This Recommendation defines functional requirements which are derived from the high-level requirements of traffic mechanisms in [ITU-T Y.1901]. Based on them, a set of traffic management mechanisms at the transport stratum in support of IPTV services are described from the perspectives of control plane, data plane and management plane. Guidelines on how such mechanisms can be used to effectively meet the functional requirements are also provided in detail. + +The network supporting IPTV services will span a number of network domains which may be designed, deployed and operated by different providers and which may differ in their traffic management capabilities. Therefore, it is expected that the network provider(s) will implement a set of these mechanisms described in this Recommendation by following the guidelines to ensure that IPTV service objectives are satisfied efficiently. Furthermore, the traffic management mechanisms also depend on the specific network architectures used for IPTV services as defined in [ITU-T Y.1910]. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +| | | +|----------------|------------------------------------------------------------------------------------------------------------------------------| +| [ITU-T G.1081] | Recommendation ITU-T G.1081 (2008), Performance monitoring points for IPTV . | +| [ITU-T Y.1291] | Recommendation ITU-T Y.1291 (2004), An architectural framework for support of Quality of Service in packet networks . | +| [ITU-T Y.1541] | Recommendation ITU-T Y.1541 (2006), Network performance objectives for IP-based services . | +| [ITU-T Y.1901] | Recommendation ITU-T Y.1901 (2009), Requirements for the support of IPTV services . | +| [ITU-T Y.1910] | Recommendation ITU-T Y.1910 (2008), IPTV functional architecture . | +| [ITU-T Y.2701] | Recommendation ITU-T Y.2701 (2007), Security requirements for NGN release 1 . | + +# 3 Definitions + +## 3.1 Term defined elsewhere + +None. + +### 3.2 Term defined in this Recommendation + +None. + +# 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|-------|--------------------------------------------| +| AF | Assured Forwarding | +| BA | Behaviour Aggregate | +| BE | Best Effort | +| BRAS | Broadband Remote Access Server | +| BTV | Broadcast TV | +| CAC | Connection Admission Control | +| CLS | Controlled Load Service | +| CoS | Class of Service | +| CS | Class Selector | +| DF | Default Forwarding | +| DNGF | Delivery Network Gateway Functions | +| DSCP | Differentiated Services Code Point | +| DSLAM | Digital Subscriber Line Access Multiplexer | +| EF | Expedited Forwarding | +| GS | Guaranteed Service | +| HG | Home Gateway | +| IGMP | Internet Group Management Protocol | +| IMS | IP Multimedia Subsystem | +| IP | Internet Protocol | +| IPDV | IP packet Delay Variation | +| IPER | IP packet Error Ratio | +| IPLR | IP packet Loss Ratio | +| IPRR | IP Packet Reordering Ratio | +| IPTD | IP Packet Transfer Delay | +| IPTV | Internet Protocol Television | +| LAN | Local Area Network | +| MAC | Media Access Control | +| MF | Multi-Field | +| MPEG | Moving Picture Experts Group | +| NAL | Network Adaptation Layer | +| NVoD | Near Video on Demand | +| OSPF | Open Shortest Path First | + +| | | +|------|-------------------------------------| +| PHB | Per-hop Behaviour | +| PVR | Private Video Recorder | +| QoS | Quality of Service | +| RACF | Resource Admission Control Function | +| RSVP | Resource Reservation Protocol | +| SLA | Service Level Agreement | +| ToS | Type of Service | +| VLAN | Virtual LAN | +| VoD | Video on Demand | +| VoIP | Voice over IP | +| VTC | Video Teleconference | +| WAN | Wide Area Network | +| WLAN | Wireless LAN | + +# 5 Conventions + +In this Recommendation, functional requirements are identified using the following convention: + +- Functional requirement number xx in clause n.m is of the form FR n.m-xx. + +# 6 Requirements + +## 6.1 High-level requirements + +Clause 6.2.2 of [ITU-T Y.1901] specifies the high-level traffic management requirements for IPTV services. For the convenience of the reader, the traffic management related mandatory requirements are listed below: + +R 6.2.2-01: The IPTV architecture is required to support traffic management mechanisms for the differential treatment of IPTV traffic. + +R 6.2.2-02: The IPTV architecture is required to support the ability to configure quality of service (QoS) rules at the delivery network gateway functions (DNGF) that govern traffic mapping (upstream or downstream) for the different IPTV services. + +R 6.2.2-03: The IPTV architecture is required to support a mechanism for assigning IPTV traffic priorities. + +R 6.2.2-04: The IPTV architecture is required to support the relevant mechanisms for IPTV traffic identification, classification and marking, policing and conditioning, scheduling and discarding. + +## 6.2 Functional requirements + +This clause describes the functional requirements, derived from high-level requirements, on three different planes: control plane, management plane and data plane. + +#### 6.2.1 Control plane functional requirements + +FR 6.2.1-01: The traffic management mechanisms are required to support admission control capability. + +FR 6.2.1-02: The traffic management mechanisms are required to support the capability of controlling network congestion and improve network utilization by selecting an appropriate path. + +FR 6.2.1-03: The traffic management mechanisms are required to support exchanging the network traffic information with the network management systems. + +#### 6.2.2 Management plane functional requirements + +FR 6.2.2-01: The traffic management mechanisms are required to enable policy control and management capabilities. + +FR 6.2.2-02: The traffic management mechanisms are required to support capability of obtaining performance information for IPTV QoS assurance. + +FR 6.2.2-03: The traffic management mechanisms are required to support service level agreement (SLA) capability in IPTV. + +#### 6.2.3 Data plane functional requirements + +FR 6.2.3-01: The traffic management mechanisms are required to enable the differentiation of traffic to provide the expected delivery of IPTV services with corresponding level of quality and reliability. + +FR 6.2.3-02: The traffic management mechanisms are required to support traffic marking capability to associate packets with different priorities. + +FR 6.2.3-03: The traffic management mechanisms are required to support buffer management capability to deal with received packets. + +FR 6.2.3-04: The traffic management mechanisms are required to support traffic queuing and traffic scheduling capability. + +FR 6.2.3-05: The traffic management mechanisms are required to support traffic policing and traffic shaping capabilities for rate control. + +FR 6.2.3-06: The traffic management mechanisms are required to support congestion management capability. + +## 6.3 Mapping among high-level requirements, functional requirements and mechanisms + +**Table 1 – Mapping table among requirements, mechanisms and sections** + +| High-level requirement | Related functional requirements | Related mechanisms | Related clause | +|------------------------|---------------------------------|------------------------------|----------------------| +| R 6.2.2-01 | FR 6.2.3-01 | traffic classification | 7.2 data plane | +| | FR 6.2.3-02 | packet marking | | +| | FR 6.2.3-03 | buffer management | | +| | FR 6.2.3-04 | queuing and scheduling | | +| | FR 6.2.3-05 | traffic policing and shaping | | +| R 6.2.2-02 | FR 6.2.1-01 | admission control | 7.1 control plane | +| | FR 6.2.1-02 | QoS routing | | +| | FR 6.2.1-03 | resource control | | +| | FR 6.2.2-01 | policy | 7.3 management plane | +| | FR 6.2.2-03 | service level agreement | | + +**Table 1 – Mapping table among requirements, mechanisms and sections** + +| High-level requirement | Related functional requirements | Related mechanisms | Related clause | +|-------------------------------|----------------------------------------|------------------------------|-----------------------| +| R 6.2.2-03 | FR 6.2.2-01 | policy | 7.3 management plane | +| | FR 6.2.2-02 | performance measurement | | +| | FR 6.2.2-03 | service level agreement | | +| R 6.2.2-04 | FR 6.2.1-01 | admission control | 7.1 control plane | +| | FR 6.2.3-01 | traffic classification | 7.2 data plane | +| | FR 6.2.3-02 | packet marking | | +| | FR 6.2.3-04 | queuing and scheduling | | +| | FR 6.2.3-05 | traffic policing and shaping | | +| | FR 6.2.3-06 | congestion avoidance | | + +# **7 Traffic management mechanisms for control plane, data plane and management plane** + +IPTV traffic management mechanisms are typically used for dealing with IPTV service traffic directly as well as other user traffic. Traffic management systems enable delivery of IPTV services with required level of quality and reliability, and can be deployed with other network mechanisms as a comprehensive QoS solution. + +This clause provides an overview of the basic traffic management mechanisms that are commonly deployed in a managed network. A provider may choose to deploy a subset of these mechanisms depending on the performance objectives of applications supported by the network. + +The traffic management framework contains mechanisms dealing with the user traffic directly, the pathways through which user traffic travels, and the operation, administration and management aspects of the network. As depicted in Figure 1, its building blocks are organized into three planes: control plane, data plane and management plane. + +![Figure 1 – Traffic management framework for QoS support. The diagram shows three main planes: Control plane (top, light blue), Data plane (middle, light green), and Management plane (right, grey). The Control plane contains 'Resource and admission control' and 'QoS routing'. The Data plane contains 'Buffer management', 'Congestion avoidance', 'Queuing and scheduling', 'Packet marking', 'Traffic shaping', 'Traffic policing', and 'Traffic classification'. The Management plane contains 'Performance measurement', 'Policy', and 'Service level agreement'. Dashed lines connect the Control plane to the Data plane, and the Management plane to both the Control and Data planes. A reference 'Y.1920(12)_F01' is at the bottom right.](d4af765160d04ecef538e5066006dc77_img.jpg) + +Figure 1 – Traffic management framework for QoS support. The diagram shows three main planes: Control plane (top, light blue), Data plane (middle, light green), and Management plane (right, grey). The Control plane contains 'Resource and admission control' and 'QoS routing'. The Data plane contains 'Buffer management', 'Congestion avoidance', 'Queuing and scheduling', 'Packet marking', 'Traffic shaping', 'Traffic policing', and 'Traffic classification'. The Management plane contains 'Performance measurement', 'Policy', and 'Service level agreement'. Dashed lines connect the Control plane to the Data plane, and the Management plane to both the Control and Data planes. A reference 'Y.1920(12)\_F01' is at the bottom right. + +**Figure 1 – Traffic management framework for QoS support** + +## **7.1 Control plane** + +#### **7.1.1 Resource and admission control** + +The traffic management systems are recommended to be capable of supporting resource and admission control functions performed in a centralized or distributed way for the IPTV service, including traffic generated by end-users over the access and core network. + +The role of the resource and admission control is to control the traffic to be admitted into the network, i.e., accept or reject IPTV services request based on the traffic demand and the current utilization of network resources. Normally the admission criteria are policy driven [b-IETF RFC 2753]. Whether traffic is admitted depends on an *a priori* SLA. In addition, the decision can depend on whether adequate network resources are available so that newly admitted traffic does not overload the network and degrade service for on-going traffic. For a service provider, the goal is to admit as much traffic as possible without degrading the quality of service of traffic flows already in progress. To achieve that, the network resource manager may be configured in the control layer to collect network information by means of data transmission between the network resource controller and the network nodes (e.g., digital subscriber line access multiplexer (DSLAM), broadband remote access server (BRAS), switches, routers, gateways) and provide them to the network management system. Meanwhile, resource and admission control meets requirements for IPTV multicast/unicast services as negotiated in the SLA. Specifically, the desired IPTV services reliability and/or availability can be requested as a priority level for resource and admission control. Resource and admission control mechanisms can efficiently support QoS assurance for IPTV services on a managed network. IPTV services supported by resource and admission control will meet unicast and multicast service demand for subscribers. Unicast resource and admission control ensures IPTV unicast services, such as video on demand (VoD) and time + +shifted TV. Multicast resource and admission control satisfies multicast services, such as broadcast TV (BTV) and near video on demand (NVoD). The policy of multicast admission control is triggered through subscribers joining multicast groups via IP multicast protocols (e.g., Internet group management protocol (IGMP) or multicast listener discovery protocol (MLD)). + +There are two resource and admission controls for IPTV services: provider-based and subscription-based. + +##### **7.1.1.1 Provider-based resource and admission control for IPTV services** + +Provider-based resource and admission control uses the exchange of signalling between user equipment and provider. + +As an example, a service provider may apply resource and admission control to IPTV services. The request for IPTV services involves the exchange of signalling between user equipment (e.g., set-top box) and the service provider video server. The service provider may reject the IPTV services request based on network resources, user status, or the current use of a specific program across all subscribers. Criteria such as user standing and the current use of a given program are related to policies set by the service provider and do not change very frequently. + +As another example, a network provider may apply resource and admission control to IPTV services. Request for IPTV services involves exchanging of signalling between user equipment and network provider, e.g., by means of equipment that maintains subscriber privileges in a local database and may receive IPTV services request. Based on subscriber privileges, equipment may reject this request or forward it to network side transparently and then allow media stream to be transferred from network side to subscriber. + +The effect of an IPTV services request on the network resources is dynamic and it varies based on the program requested. For instance, requesting high definition content will impose more demand on the network compared to the demand generated when standard definition content is requested. + +##### **7.1.1.2 Subscription-based resource and admission control for IPTV services** + +Currently, linear TV service is provided on a subscription basis through cable or satellite. Once subscribed, the linear TV service will continue without interruption unless subscription is terminated by either the provider or the end-user. This behaviour must also be allowed for IPTV services, i.e., linear TV service must continue to be on subscription basis. A service provider ensures that the network is properly engineered to accommodate the number of subscribers that match its business model. + +There are scenarios where multiple set-top boxes may exist in a single home and reception of multiple video streams may be restricted due to the access bandwidth. For such cases the service provider may need to limit the number of streams admitted for a single subscriber. There are also times that a subscriber may request video streams that are denied due to insufficient bandwidth as per SLA. + +#### **7.1.2 QoS routing** + +The text in this clause is based on clause 7.2 of [ITU-T Y.1291] with modifications. This mechanism is used to control network congestion and improve network utilization by selecting an appropriate path. The path selected is most likely not the traditional shortest path. Depending on the specifics and the number of QoS metrics involved, computation required for path selection can become prohibitively expensive as the network size grows. Hence practical QoS routing schemes consider mainly cases for a single QoS metric (e.g., bandwidth or delay) or for dual QoS metrics (e.g., cost-delay, cost-bandwidth, and bandwidth-delay). To further reduce the complexity of path computation, various routing strategies can be utilized. Based on how the state information is maintained and how the search of feasible paths is carried out, different strategies such as source routing, hierarchical routing, and distributed routing can be used. Also based on QoS granularity + +and model expansibility, different mechanisms such as IntServ, DiffServ and IntServ over DiffServ (refer to [b-IETF RFC 2998]) can be used. In an IntServ over DiffServ in which the network is divided into several QoS domains, the QoS domain is divided into a QoS domain connected to the source terminal, a QoS domain connected to the destination terminal and other intermediate QoS domains. Each QoS comprises a plurality of QoS edge routers and a plurality of QoS core routers. A QoS server adopts its own resource allocation scheme so that end-to-end QoS can be achieved based on resources allocated in a single QoS domain or multiple QoS domains. In addition, depending on how multiple QoS metrics are handled, mechanisms, such as metric ordering and sequential filtering can be used, which may trade global optimality with reduced computational complexity [b-IETF RFC 2386]. + +The path selection process involves the knowledge of the flow's QoS requirements and characteristics and (frequently changing) information on the availability of network resources (expressed in terms of standard metrics such as available bandwidth and delay). The knowledge is typically obtained and distributed with the aid of signalling protocols. For example, the resource reservation protocol (RSVP) [b-IETF RFC 2205] can be used for conveying a flow's requirements and characteristics and open shortest path first (OSPF) extensions as defined in [b-IETF RFC 2676] for resource availability. Compared to shortest-path routing, which selects optimal routes based on a relatively constant metric (i.e., hop count or cost), QoS routing tends to entail more frequent and complex path computation and more signalling traffic. + +It is important to note that QoS routing provides a means to determine only a path that can likely accommodate the requested performance. To guarantee performance on a selected path, QoS routing needs to be used in conjunction with resource reservation to reserve necessary network resources along the path. + +QoS routing can also be generalized to apply to traffic engineering. (Concerning slowly-changing traffic patterns over a long time scale and a coarse granularity of traffic flows, traffic engineering encompasses traffic management, capacity management, traffic measurement and modelling, network modelling, and performance analysis.) To this end, routing selection often takes into account a variety of constraints such as traffic attributes, network constraints, and policy constraints [b-IETF RFC 3272]. Such generalized QoS routing is also called constraint-based routing. + +### **7.2 Data plane** + +Traffic management in data plane is a set of generic network mechanisms for controlling the network service response to a service request, which can be specific to a network element, or for signalling between network elements, or for controlling and administering traffic across a network, mainly including bandwidth allocation, packet classification/marketing, congestion management, congestion avoidance, traffic policing, traffic shaping, etc. + +The basic processing sequence is shown in Figure 2. It describes the traffic processing procedure of transport functions in the data plane, mainly including traffic classification, traffic conditioning, traffic schedule and queues, etc. The detailed procedure for traffic processing is described in clause 7.2. + +![Diagram illustrating the basic processing sequence of traffic. The process starts with 'Packet should be transmitted' (represented by colored bars). This leads to 'Classification/Marking' (a large blue arrow). The traffic then enters a 'Token bucket' (a cylinder with a vertical line and 'Token' label). From the token bucket, traffic can be 'Discarding' (indicated by orange and red triangles) or proceed to 'Other' (a blue arrow). The 'Other' path leads to 'In queuing' (a blue arrow). From 'In queuing', traffic is distributed into multiple 'Queue' blocks (Queue 0, Queue 1, Queue 2, ..., Queue N). These queues then lead to 'Out queuing' (a blue arrow), which finally results in 'Transmission' (represented by colored bars). The diagram also includes labels for 'Traffic policing' and 'Traffic shaping' (orange triangles) and 'Congestion avoidance' (red triangles). The identifier 'Y.1920(12)_F02' is present in the bottom right corner.](33ed1f9b27c7c21c797aa928b0f06851_img.jpg) + +Diagram illustrating the basic processing sequence of traffic. The process starts with 'Packet should be transmitted' (represented by colored bars). This leads to 'Classification/Marking' (a large blue arrow). The traffic then enters a 'Token bucket' (a cylinder with a vertical line and 'Token' label). From the token bucket, traffic can be 'Discarding' (indicated by orange and red triangles) or proceed to 'Other' (a blue arrow). The 'Other' path leads to 'In queuing' (a blue arrow). From 'In queuing', traffic is distributed into multiple 'Queue' blocks (Queue 0, Queue 1, Queue 2, ..., Queue N). These queues then lead to 'Out queuing' (a blue arrow), which finally results in 'Transmission' (represented by colored bars). The diagram also includes labels for 'Traffic policing' and 'Traffic shaping' (orange triangles) and 'Congestion avoidance' (red triangles). The identifier 'Y.1920(12)\_F02' is present in the bottom right corner. + +**Figure 2 – The basic processing sequence of traffic** + +#### 7.2.1 Traffic classification + +In traffic management, packet classifiers are used to select packets in a traffic stream based on the content of some portion of the packet header. The behaviour aggregate (BA) classifier classifies packets based on the differentiated services (DS) code point only. The multi-field (MF) classifier selects packets based on the value of a combination of one or more header fields, such as source address, destination address, DS field, protocol ID, source port and destination port numbers and other information such as incoming interface. It is recommended to follow the guidelines specified in [b-IETF RFC 4594]. + +#### 7.2.2 Traffic conditioning + +A traffic conditioner which refers to [b-IETF RFC 2475] is an entity that performs traffic conditioning functions where meter, marker, shaper and dropper are optional. A traffic stream is selected by a classifier, which steers the packets to a logical instance of a traffic conditioner. A meter is used (where appropriate) to measure the traffic stream against a user profile. The state of the meter with respect to a particular packet (e.g., whether it is in- or out-of-profile) may be used to affect a marking, dropping or shaping action. + +During traffic conditioning, the following are required in access network for supporting multimedia services such as IPTV services: + +- QoS provisioning per subscriber and per service; +- traffic classification based on multiple header fields (e.g., 5-tuple or 6-tuple); +- minimum bandwidth guarantee; +- traffic shaping/policing; +- advanced packet queuing and scheduling; +- packet marking IP differentiated services code point (DSCP), Ethernet priorities [b-IEEE 802.1q], etc.); +- congestion avoidance. + +#### 7.2.3 Buffer management + +Queue or buffer management deals with which packets, awaiting transmission, to store or drop. An important goal of buffer management is to minimize the steady-state buffer size while not underutilizing the link, as well as avoiding the monopolization of the available buffer space by a single flow [b-IETF RFC 2309]. Schemes for buffer management differ mainly in the allocation of the buffer space and the criteria for dropping packets. + +A common criterion for dropping packets is the buffer reaching its maximum size. Packets are dropped when the buffer is full. Determining which packet to drop depends on the drop disciplines, for example: + +- "Tail drop" drops newly arriving packets. This is the most common strategy since it is easy to implement. +- "Front drop": A buffer space for newly arriving packets is made available by dropping the packet at the front of the queue, provided that the length of the newly arriving packet is less than or equal to the dropped packet. +- "Random drop": A buffer space for the newly arriving packet is made available by randomly choosing a packet to drop from the queue, provided that the length of the newly arriving packet is less than or equal to the dropped packet. + +#### **7.2.4 Traffic queuing and scheduling** + +This mechanism controls which packets to select for transmission on an outgoing link. Incoming traffic is held in a queuing system, which is made of, typically, multiple queues and a scheduler. Governing the queuing system is the queuing and scheduling discipline it employs. There are several key approaches such as first-in-first-out and round-robin, which have been defined in [ITU-T Y.1291]. + +### **7.3 Management plane** + +### **7.3.1 Performance measurement** + +The performance of complete IPTV service delivery to an end user can be monitored by service provider/network provider at the performance monitoring points [ITU-T G.1081]. Monitored performance characteristics, across a single domain or multiple domains, can be integrated with existing or new operations support systems (OSSs) and/or network management systems (NMSs) for IPTV service and network elements to meet the appropriate performance objectives. + +### **7.3.2 SLA** + +A SLA in IPTV service typically represents the agreement between an end user and one or more providers of IPTV service that specifies the level of availability, service delivery, performance, operation, billing compensations or other attributes of the IPTV service. It may include the parameters and their values that define the IPTV service offered to an end user by a network. Overall, [b-ITU-T E.860] defines a general SLA framework for a multi-vendor service. + +#### **7.3.3 Policy** + +A policy is typically a set of rules which represents the provider's equipment operation and management criteria for resource usage and access. It can be specific to the needs of objective statements identified in SLA(s). The service and/or network provider can implement mechanisms in the control plane to manage its IPTV service based on policies. Policy-based admission control functionality, such as the resource admission control function (RACF) [b-ITU-T Y.2111], is recommended to be deployed by the IPTV service provider and/or network provider over the IP network for ensuring stable IPTV service provisioning and management. + +# **8 Guidelines to use IPTV traffic management mechanisms** + +This clause consists of two parts: mapping of traffic management mechanisms into the corresponding functions in IPTV functional architecture and usage guidelines of such mechanisms for IPTV services. + +## 8.1 Mapping of traffic management mechanisms to functions in IPTV functional architecture + +![Figure 3 – Traffic management in IPTV architecture. This diagram illustrates the mapping of traffic management mechanisms to various functional blocks within the IPTV architecture. The architecture is organized into four main vertical sections: End-user functions, Application functions, Network functions, and Management functions, with a separate Content provider functions section on the right. End-user functions include IPTV terminal functions, Application client functions, SCP client functions, Content delivery client functions, Control client functional block, and Home network functions. Application functions include IPTV application functions, Application profile functional block, Content preparation functions, SCP functions, Service control functions, and Content delivery functions. Network functions include Authentication and IP allocation function block, Resource control functional block (with Resource and admission control and QoS routing), Access network functions (with Traffic classification, Traffic policing, Traffic marking, Traffic scheduling, Traffic queuing, Traffic shaping, and Traffic identification), Edge functions (with Traffic shaping and Traffic scheduling), and Core transport functions (with Traffic classification, Traffic policing, Traffic marking, Traffic shaping, Traffic queuing, Traffic scheduling, and Traffic identification). Management functions include Application management functional block, Service control management functional block, Content delivery management functional block, End-user device management functional block, and Transport management functional block (with Policy, SLA, and Performance). Content provider functions include Content and metadata sources. Bold and solid lines indicate direct relationships between functions, functional blocks, or functions and functional blocks.](c85ded401105f62f2d6ff26b3b5eb4af_img.jpg) + +Figure 3 – Traffic management in IPTV architecture. This diagram illustrates the mapping of traffic management mechanisms to various functional blocks within the IPTV architecture. The architecture is organized into four main vertical sections: End-user functions, Application functions, Network functions, and Management functions, with a separate Content provider functions section on the right. End-user functions include IPTV terminal functions, Application client functions, SCP client functions, Content delivery client functions, Control client functional block, and Home network functions. Application functions include IPTV application functions, Application profile functional block, Content preparation functions, SCP functions, Service control functions, and Content delivery functions. Network functions include Authentication and IP allocation function block, Resource control functional block (with Resource and admission control and QoS routing), Access network functions (with Traffic classification, Traffic policing, Traffic marking, Traffic scheduling, Traffic queuing, Traffic shaping, and Traffic identification), Edge functions (with Traffic shaping and Traffic scheduling), and Core transport functions (with Traffic classification, Traffic policing, Traffic marking, Traffic shaping, Traffic queuing, Traffic scheduling, and Traffic identification). Management functions include Application management functional block, Service control management functional block, Content delivery management functional block, End-user device management functional block, and Transport management functional block (with Policy, SLA, and Performance). Content provider functions include Content and metadata sources. Bold and solid lines indicate direct relationships between functions, functional blocks, or functions and functional blocks. + +**Figure 3 – Traffic management in IPTV architecture** + +[ITU-T Y.1910] defines an overview of IPTV architecture intended to support IPTV services. In order to provide guidance on the use of traffic management mechanisms, it is necessary to implement these mechanisms in the functions of IPTV architecture. Figure 3 illustrates how the traffic management mechanisms are involved in IPTV architecture. The blue building blocks in Figure 3 indicate the traffic management mechanisms suggested to be implemented in the corresponding functions. The bold and solid lines in the figure represent direct relationships between functions, functional blocks, or functions and functional blocks. + +The mechanisms from data plane in this Recommendation are recommended to be mainly implemented in home network functions located in the home network and transport functions, which include access network functions, edge network functions and core network functions. Home network function and transport function verify transport resource availability and exchange with the control plane to enforce policy decision from control plane and handle traffic priority and so on. In the home network, traffic classification and marking mechanisms are implemented for differentiation at the service level. In the access network, traffic classification and marking mechanisms are used to isolate flows at a customer level. Traffic queuing, shaping, policing and scheduling are implemented to enable controlling traffic flow in different queues with different priorities. In the edge function, upstream traffic flows are aggregated to get traffic shaping and scheduling control. In the core network, traffic identification mechanisms can be used for upstream flows. For downstream flows, traffic classification and traffic marking mechanisms are used to differentiate different services. Traffic queuing, shaping, policing and scheduling are recommended to control traffic flow in different queues with different priorities in the core network. + +The mechanisms from control plane in this Recommendation are recommended to be mainly implemented in resource control functional block of network functions. Resource and admission control located in the resource control functional block can be triggered by requests from the IPTV service control block and then interact with transport functions to check user status and network resources for controlling service traffic to be admitted or not. It also performs bandwidth reservation and allocation control, traffic classification, marking, policing, etc. QoS routing mechanisms located in the resource control functional block are able to interact with other functions to obtain the necessary routing information, compute paths and then send the results back to transport functions. + +The mechanisms specified in management plane are required to be implemented in the transport management functional block of the management functions to provide overall system status monitoring and configuration. + +## **8.2 Guidelines for the use of traffic management mechanisms for IPTV services** + +IPTV services as listed in [b-ITU-T Y-Sup.5] usually consist of several service applications which can have different QoS requirements regarding the transport of related data. For example, real-time telephony applications consume relatively low sustained bandwidth (a typical voice connection is less than 100 kbit/s), they have stringent jitter and latency requirements. Video requires a high-level of sustained bandwidth per channel (a few hundred kbit/s to several Mbit/s), however some latency is tolerable. Online gaming and financial applications typically require relatively small amounts of extremely time-sensitive data. [ITU-T Y.1541] defines performance classes and Appendix I provides a guideline on potential mappings of various IPTV services into performance classes. + +Performance classes of various IPTV services represent the network service class subscribed by the end user device (e.g., CPE). And they should be carried along with the QoS resource information from the control plane to the transport functions across the core network, access network and home network in the data plane. Within the access, core and home network, it is recommended that three important abilities be required in a network designed to meet service-specific requirements modulated with subscriber-specific SLAs, including: + +- checking conformance (i.e., policing); +- making discard decisions (i.e., resource and admission control, buffer management); +- regulating traffic flow in various queues (i.e., traffic scheduling). + +The following appendices illustrate the use of different traffic management mechanisms. Appendix II provides an example guideline on how to implement traffic management mechanisms for the core network, access network and home network. Appendix III gives an illustration on the use of the admission control mechanism for VoD service in an IP multimedia subsystem (IMS)-based IPTV service scenario as defined in [ITU-T Y.1910]. Appendix IV gives implementation guidelines for management plane mechanisms. + +In addition, to ensure better-quality IPTV services and meet QoS requirements of various service applications, it is recommended to provide cross-plane interaction between different planes in the IPTV network. Taking the multicast resource management as an example, IPTV network supports multicast traffic and multicast admission control for QoS of IPTV services. The multicast admission control system allocates and reserves resource and controls IPTV multicast transportation based on users' admission control policy for subscribers. The multicast replication point forwards the IPTV multicast stream to subscribers according to their successful resources allocation in the network control system. In such a case, IPTV traffic management systems are recommended as an option to interact with policy-based management functions to install the management decisions relative to multicast, and use RACF [b-ITU-T Y.2111] for multicast resource management. Appendix V provides additional discussion of cross-layer interaction between different planes for IPTV services. + +Note that, due to the diversity of IPTV services and performance class requirements, the mapping from traffic management mechanisms to IPTV service and performance classes could be variable and complex. Any additional traffic management usage cases beyond the above guidelines are for further study. + +# **9 Security considerations** + +The major security requirements for the traffic management function are: + +- protection of the information exchange within three planes and with other functions; +- protection of the information contained in all function entities involved in traffic management; +- ensuring the availability of the traffic management function; +- preventing illegitimate access; +- maintaining the confidentiality of end-user information. + +For any additional security requirements, this Recommendation aligns with the security requirements in [ITU-T Y.2701]. + +# Appendix I + +## Discussion on ITU-T Y.1541 performance classes for IPTV + +(This appendix does not form an integral part of this Recommendation.) + +[ITU-T Y.1541] defines eight network classes for IP-based service performance. While the classes from 0 to 5 are defined as a set of normative QoS classes, the classes 6 and 7 are defined as a set of provisional QoS classes. These classes cover a wide range of services including real-time telephony, multimedia applications and interactive data transfer. Each class defined in [ITU-T Y.1541] is characterized by a set of performance parameters bounded by agreed upon parameter values. The class performance parameters of [ITU-T Y.1541] are: + +- IP packet transfer delay (IPTD) +- IP packet delay variation (IPDV) +- IP packet loss ratio (IPLR) +- IP packet error ratio (IPER) + +In order to classify any given service as compatible with a given performance class, it is necessary to carry out a supporting analysis that demonstrates the compliance of the observed performance parameters within the bounds specified for the desired class. The analysis for the desired service needs to consider proper evaluation time intervals, the reference path of the desired service and packet sizes. To provide guidance on traffic management for any given IPTV service component, a summary of [ITU-T Y.1541] performance class definitions, performance objectives and guidance for applicability is discussed below. + +Table I.1 summarizes all pertinent information from [ITU-T Y.1541] as given in Tables 1, 2 and 3 of [ITU-T Y.1541]. + +**Table I.1 – ITU-T Y.1541 IP network QoS class definitions +and network performance objectives/applications** + +| QoS class | IPTD | IPDV | IPLR | IPER | IPRR | Applications (examples) | +|---------------------------------------------------------------------------|--------|-------|--------------------|--------------------|--------------------|----------------------------------------------------------------| +| 0 | 100 ms | 50 ms | $1 \times 10^{-3}$ | $1 \times 10^{-4}$ | – | Real-time, jitter sensitive, highly interactive (VoIP, VTC) | +| 1 | 400 ms | 50 ms | $1 \times 10^{-3}$ | $1 \times 10^{-4}$ | – | Real-time, jitter sensitive, highly interactive (VoIP, VTC) | +| 2 | 100 ms | U | $1 \times 10^{-3}$ | $1 \times 10^{-4}$ | – | Transaction data, highly interactive (signalling) | +| 3 | 400 ms | U | $1 \times 10^{-3}$ | $1 \times 10^{-4}$ | – | Transaction data, interactive | +| 4 | 1 s | U | $1 \times 10^{-3}$ | $1 \times 10^{-4}$ | – | Low loss only (short transactions, bulk data, video streaming) | +| 5 | U | U | U | U | – | Traditional applications of default IP networks | +| 6 | 100 ms | 50 ms | $1 \times 10^{-5}$ | $1 \times 10^{-6}$ | $1 \times 10^{-6}$ | | +| 7 | 400 ms | 50 ms | $1 \times 10^{-5}$ | $1 \times 10^{-6}$ | $1 \times 10^{-6}$ | | +| NOTE 1 – U = undefined | | | | | | | +| NOTE 2 – QoS classes 6 and 7 are defined as a set of provisional classes. | | | | | | | + +Table I.2 provides an illustrative example of potential ITU-T Y.1541 performance class mappings for a variety of IPTV service applications. As indicated in clause 8, the precise mappings require extensive and detailed examination based on component characteristics (e.g., packet size) and network conditions (reference model). Such mappings are for further study. + +**Table I.2 – Illustrative example of potential mapping of IPTV service components to ITU-T Y.1541 QoS classes** + +| IPTV service | Service applications | Example IPTV services | ITU-T Y.1541 QoS class | | | | | | | | +|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------|-------------------------------------------------|------------------------|---|---|---|----|----|---|---| +| | | | 5 | 4 | 3 | 2 | 1 | 0 | 7 | 6 | +| Streaming | Live TV content | Linear TV including pay per view and multi-view | | | | | | ✓1 | | ✓ | +| | Video content | VoD, network PVR, time-shift TV | | | | | ✓1 | | ✓ | | +| | Audio content | Music on Demand | | | | | ✓ | | | | +| | Content control | VoD, network PVR, time-shift TV | | | | ✓ | | | | | +| | Live speech | Voice call, audio conference | | | | | | ✓ | | | +| | Live low-resolution video content | Video telephony, video conference | | | | | | ✓ | | | +| Download | Video content | Push VoD, near VoD | | ✓ | | | | | | | +| | Data | Content guides, pictures, applications download | ✓ | | | | | | | | +| Upload | Video content | User generated content | | ✓ | | | | | | | +| Message exchange | Interactive | Chatting | | | ✓ | | | | | | +| | Non-interactive | Messaging, email | ✓ | | | | | | | | +| Middleware/application | Portal | Web services, information services | | | ✓ | | | | | | +| | Payment transactions | VoD rental | | | ✓ | | | | | | +| NOTE – Consumer television quality can be achieved using ITU-T Y.1541 QoS classes 0 and 1 together with the DVB-IP AL-FEC mechanism, and the enhanced decoder according to [b-ETSI TS 102034], clause E.5.1.2. | | | | | | | | | | | + +NOTE 1 – QoS classes 6 and 7 are defined as a set of provisional classes. + +NOTE 2 – It is recognized that under network congestion conditions, some traffic may not achieve the objectives of their assigned class. This may be managed by: + +- Recommending appropriate traffic management methods specified in this Recommendation to increase the likelihood of meeting ITU-T Y.1541 class objectives. +- Specifying an appropriate percentage of time when the objectives of the desired class will be met, and possibly specifying another class that would be applicable during the remaining percentage of time. The determination of the percentage of time spent in the specified classes is for further study. + +## Appendix II + +## Traffic management for core network, access network and home network + +(This appendix does not form an integral part of this Recommendation.) + +### II.1 Traffic management for the core network + +#### II.1.1 Traffic management mechanisms for the core network + +This clause describes an overview of the IP traffic management mechanisms including integrated services and differentiated service. + +IP networks allow both reservation and differentiated models for QoS support and traffic management. The IP reservation model is that based on the IP integrated services (IntServ) and allows the use of resource reservation protocol (RSVP) signalling protocol for bandwidth reservation. Two service classes are defined in the context of IP IntServ: + +- Guaranteed service (GS) defines a service type where all packets belonging to the same session are delivered within a deterministic delay bound. Routers along the path of the session must employ appropriate scheduling algorithm and reserve resources to ensure that the delay bound is always satisfied. +- The controlled load service (CLS) provides a service equivalent to a "lightly" loaded best effort network. + +IP networks are also capable of supporting a differentiated model with the IP differentiated service (DiffServ). The IP differentiated model defines a set of edge functions and a number of per-hop behaviour (PHB). Edge functions are those related to classification, metering, marking, dropping and shaping. A PHB defines an externally observable treatment applied at a network node to a DiffServ behaviour aggregate. A number of PHBs are defined by the IETF in the context of IP DiffServ: + +- Expedited forwarding (EF): The intent of the EF behaviour is to provide the building block for the creation of low loss, low delay, and low delay variation services. The EF PHB definition mandates that the EF packets should ideally be served at a rate $R$ or faster and bounds the deviation of the actual departure time for each packet by the relationship [b-IETF RFC 3246]: + +$$d_j \leq f_j + E_a$$ +$$f_j = \max\left[a_j, \min\left[d_{j-1}, f_{j-1}\right]\right] + \frac{\ell_j}{R}$$ + +Where $d_j$ is the actual departure time of the $j$ -th packet, $f_j$ is the target departure time of the $j$ -th packet, and $E_a$ is an error term bounding the deviation of the actual departure time from the target departure time. $E_a$ is a function of the nodal scheduler implementation. $\ell_j$ is the length of the $j$ -th packet. The above relationship paves the way for the specification of a delay bound as long as the aggregate EF traffic adheres to some traffic pattern (e.g., as specified by a token bucket). + +- Assured forwarding (AF): The AF PHB group defines four AF classes. For each class three discard precedence levels are defined (AF*ij*, $i=1, 2, 3$ or $4$ and $j=1, 2$ or $3$ ). No priority order is defined among the four AF classes. [b-IETF RFC 2597] requires that each node in the networks to allocate certain amount of forwarding resources for each AF class to assure forwarding of the IP packets. However, no delay or loss bounds are defined. + +- Class selector (CS): The CS PHB group is defined for DiffServ to be backward compatible with legacy routers that support the type of service (ToS) bits in the IP packet header. CS PHB group defines eight forward treatments where packets belonging to CS*i* are served before packets marked with CS*j* as long as $i > j$ . It effectively defines a straight priority discipline with CS1 being reserved for the default forwarding (DF) used for the traditional IP best effort (BE) service. + +IP DiffServ is scalable compared to IP IntServ since it does not require per flow reservation, scheduling and buffering. In IP DiffServ flow information is available at the network edge while nodal behaviour is applied on an aggregate basis. + +IP DiffServ paradigm does not include the definition of service classes. However service classes could be realized by proper specification of edge rules and consistent application of PHB by the different nodes in the network. + +#### II.1.2 IP traffic management approach applicable to IPTV service in core network + +The core IP network transporting IPTV services is expected to be well-engineered and shared between a number of applications including data and voice support. Since IP DiffServ allows the core IP network to scale to a large number of flows, it is also expected that the network will be equipped with DiffServ capabilities in terms of scheduling implementation that supports all or some of the DiffServ PHBs. It can be shown that if the EF traffic arriving at an interface is bounded by a token bucket with parameters ( $B, R$ ) then the delay of any packet departing the interface is bounded by: + +$$D \leq \frac{B}{R} + E_a$$ + +where: + +$R$ (in bytes per second) is the token bucket rate + +$B$ (in bytes) is the token bucket size + +$E_a$ typically represents the value of non-rate dependent delay which may be specified by the combination of fixed minimum delay and variable delay. The specific definition for IP traffic control and congestion control algorithms including token bucket can be found in Annex A of [b-ITU-T Y.1221]. + +IPTV services that require stringent loss and delay constraints may be supported using EF PHB. The use of PHB will ensure that IPTV packets are transported within a certain delay bound with almost no loss as long as the aggregate burst of the offered EF traffic is within some bound. The EF PHB must be configured with enough resources to satisfy the delay requirements of video packets. Since performance of video application is sensitive to packet loss, sufficient buffer needs to be allocated to ensure that it accommodates a burst size equal to $B$ . + +It is also possible to support IPTV services using AF PHB group as long as the AF class or classes designated for IPTV services are configured with the amount of resources needed to assure the service QoS parameters. Unlike the EF PHB, there is no delay constraint associated with the definition of the AF PHB. However, use of the AF offers the added benefit of selectively discarding video packets based on their relative importance. This will require the relative importance of video information to be inherited by the IP layer. + +An IP node supporting the CS PHB group implies that an absolute priority scheduler is in place. IPTV services shall be supported at a priority level high enough to maintain its quality assurances. Starvation of classes supporting IPTV services must always be avoided. + +### **II.2 Traffic management for the access network** + +#### **II.2.1 Traffic management mechanisms for the access network** + +Access networks should have the means to control the following functions for traffic management: + +- per-packet/flow and per-class basis connection admission control (CAC) +- per-user and per-service QoS provisioning +- per-packet/flow mapping between IP DSCP markings and Ethernet priorities [b-IEEE 802.1q] + +#### **II.2.2 Traffic management approach applicable to IPTV services in the access network** + +Generic mechanisms are required for traffic management of upstream and downstream directions in an access network. + +##### **a) Upstream** + +To support quality of service in access networks including broadcasting traffic, network nodes should have the following requirements in the upstream direction: + +- Guarantee of minimum bandwidth +- Guarantee of bandwidth quality per service (e.g., VoIP, video conference, and IPTV) + +To address the above 2 requirements, the following functions are recommended to be supported: + +- 5-tuple based classification and policing +- Priority queuing +- Traffic shaping + +##### **b) Downstream** + +To support QoS in access networks including broadcasting traffic, network nodes are recommended to guarantee availability of minimum bandwidth per service in the downstream direction. + +To support the above, access networks are recommended to have the following functions in downstream: + +- Per-packet/flow and per-class basis CAC for broadcast channels +- Traffic shaping/policing per subscriber +- Support of class of service (CoS) based DSCP + - 5-tuple classification + - DSCP marking +- Mapping between IP DSCP markings and Ethernet priorities [b-IEEE 802.1q] + +### **II.3 Traffic management for home network** + +This clause describes home network environment and the need for traffic management for IPTV services. A possible architecture for the home network is shown in [b-HGI]. + +![Figure II.1 – Home network architecture diagram. The diagram shows a Home Gateway (HG) connected to an Ethernet switch. The HG has two external interfaces: 'Low-rate upstream access' and 'High-rate downstream access'. It also has internal connections to various devices: two telephones (100 Mbit/s), a desktop computer (100 Mbit/s), and a laptop (100 Mbit/s). The Ethernet switch is connected to a desktop computer (100 Mbit/s) and a laptop (100 Mbit/s). A dashed line labeled 'Wireless LAN' connects the Ethernet switch to a laptop. An 'Ethernet-PLT bridge' is connected to the HG (100 Mbit/s) and a desktop computer (<10 Mbit/s). A label 'Merging WAN-LAN and transit traffic' points to the HG. A file identifier 'Y.1920(12)_Fil.1' is in the bottom right corner.](7133ccf78043568ca62ecbcd43628a4a_img.jpg) + +Figure II.1 – Home network architecture diagram. The diagram shows a Home Gateway (HG) connected to an Ethernet switch. The HG has two external interfaces: 'Low-rate upstream access' and 'High-rate downstream access'. It also has internal connections to various devices: two telephones (100 Mbit/s), a desktop computer (100 Mbit/s), and a laptop (100 Mbit/s). The Ethernet switch is connected to a desktop computer (100 Mbit/s) and a laptop (100 Mbit/s). A dashed line labeled 'Wireless LAN' connects the Ethernet switch to a laptop. An 'Ethernet-PLT bridge' is connected to the HG (100 Mbit/s) and a desktop computer (<10 Mbit/s). A label 'Merging WAN-LAN and transit traffic' points to the HG. A file identifier 'Y.1920(12)\_Fil.1' is in the bottom right corner. + +**Figure II.1 – Home network architecture** + +As shown in Figure II.1, the home network employs multiple local area network (LAN) technologies. Prominent among these technologies are the wireless LAN (WLAN) based on [b-IEEE 802.11] and wire-line Ethernet and bridges based on [b-IEEE 802.3] and [b-IEEE 802.1d]. The home gateway (HG) is the interface of the home network to provide access network. HG receives and sends packets from and to the wide area network (WAN). It also supports transit (LAN-to-LAN) traffic. The main function of the HG is the classification of the packets as they traverse the HG to and from the WAN and setting the appropriate priority level using the IP DSCP or the Ethernet user priority bits. Possible classification criteria include type of LAN, media access control (MAC) addressing and virtual LAN (VLAN) tag. HG requirements include the support of multiple queues managed using strict priority or weighted round robin at the WAN egress ports. It requires the support buffer management mechanisms. + +Home Ethernet switches may support the existence of the user priority bits (also known as p-bits). User priority bits define up to eight priority levels that can be used to identify traffic classes such as voice, video, best effort, etc. + +The current IEEE 802.11 standards support rates up to 54 Mbit/s. Emerging IEEE 802.11 standards are expected to support rates up to 600 Mbit/s based on [b-IEEE 802.11n]. Traffic management is supported on a WLAN using [b-IEEE 802.11e] which defines four access categories that effectively supports four priority levels. + +## Appendix III + +## Admission control example for IMS based architecture + +(This appendix does not form an integral part of this Recommendation.) + +Figure III.1 shows an example of admission control for on-demand service in an IPTV service scenario using the IP Multimedia Subsystem (IMS)-based architecture as defined in [ITU-T Y.1910]. + +![Figure III.1: Admission control example for IMS based architecture. This diagram illustrates the IMS-based architecture for admission control in an IPTV service scenario. It is organized into five main vertical sections: End-user functions, Application functions, Management functions, Content provider functions, and Home network functions. The End-user functions section includes ITF (Application client functions, SCP client functions) and Home network functions (Delivery network gateway functional block). The Application functions section includes Transaction protocol, IPTV application functions, Application profile functional block, Metadata, Content preparation functions, and SCP functions. The Management functions section includes Application management functional block, Service control management functional block, Content delivery management functional block, End-user device management functional block, and Transport management functional block. The Content provider functions section includes Content and metadata sources. The Home network functions section includes Authentication and configuration protocol, Network attachment control functions (NACF), Resource and admission control functions (RACF), and NGN transport stratum functions (Access network functions, Edge functions, Core transport functions). The Core IMS functions section includes Service support functions (Data session, Delivery protocols), Service control functions (Service user profile functional block), and Content delivery functions (Content distribution and location control functions, Content delivery and storage functions). The diagram shows the flow of admission control: Ctrl 1 (Session protocol) from Session client functional block to Core IMS functions; Ctrl 2 (Service user profile functional block) from Core IMS functions to Service control functions; Ctrl 3 (Transaction protocol) from IPTV application functions to Core IMS functions; Ctrl 4 (Resource and admission control functions (RACF)) from Core IMS functions to Resource and admission control functions; and Ctrl 5 (Content delivery and storage functions) from Core IMS functions to Content delivery functions. A Data session flow is also shown between Content delivery client functions and Content delivery and storage functions.](58f4167687de8d7339594e5f6fbe0bc6_img.jpg) + +Y.1910(12)\_Fill.1 + +Figure III.1: Admission control example for IMS based architecture. This diagram illustrates the IMS-based architecture for admission control in an IPTV service scenario. It is organized into five main vertical sections: End-user functions, Application functions, Management functions, Content provider functions, and Home network functions. The End-user functions section includes ITF (Application client functions, SCP client functions) and Home network functions (Delivery network gateway functional block). The Application functions section includes Transaction protocol, IPTV application functions, Application profile functional block, Metadata, Content preparation functions, and SCP functions. The Management functions section includes Application management functional block, Service control management functional block, Content delivery management functional block, End-user device management functional block, and Transport management functional block. The Content provider functions section includes Content and metadata sources. The Home network functions section includes Authentication and configuration protocol, Network attachment control functions (NACF), Resource and admission control functions (RACF), and NGN transport stratum functions (Access network functions, Edge functions, Core transport functions). The Core IMS functions section includes Service support functions (Data session, Delivery protocols), Service control functions (Service user profile functional block), and Content delivery functions (Content distribution and location control functions, Content delivery and storage functions). The diagram shows the flow of admission control: Ctrl 1 (Session protocol) from Session client functional block to Core IMS functions; Ctrl 2 (Service user profile functional block) from Core IMS functions to Service control functions; Ctrl 3 (Transaction protocol) from IPTV application functions to Core IMS functions; Ctrl 4 (Resource and admission control functions (RACF)) from Core IMS functions to Resource and admission control functions; and Ctrl 5 (Content delivery and storage functions) from Core IMS functions to Content delivery functions. A Data session flow is also shown between Content delivery client functions and Content delivery and storage functions. + +Figure III.1 – Admission control example for IMS based architecture + +The admission sequence involves the generation of the request by the session client of the IPTV terminal function using a session level protocol (Ctrl 1 flow in Figure III.1). The request is received by the core IMS. The core IMS checks with the service user profile (Ctrl 2 flow in Figure III.1) and IPTV application (Ctrl 3 in Figure III.1) if the user is allowed to access the specific service and content and checks with the resource and admission control function (Ctrl 4 flow in Figure III.1) if the required resources are available. Based on this information the incoming request may be accepted or rejected and the result of the admission process is reported back to the session client (Ctrl 1 flow in Figure III.1). In case the request is accepted the content delivery control function is notified (Ctrl 5 flow in Figure III.1) and the session is established between the media client IPTV terminal and the content delivery and storage function (data session flow in Figure III.1). + +## **Appendix IV** + +## **An example of guidelines for management plane mechanisms** + +(This appendix does not form an integral part of this Recommendation.) + +### **IV.1 Management plane** + +In order to support video traffic, the network should provide consistent carrier grade quality service across the network. Current networks seldom deliver the required OAM functionalities in management plane thus forcing IPTV operators to deploy very complex solutions to monitor the IPTV signals. Typically, monitoring the quality is done by decoding all the IPTV signals and showing them on screens on various locations in the network. So it is recommended that a set of management functions for NGN should be designed to support the enforcement of the QoS mechanisms. + +### **IV.2 Performance measurement and management** + +IPTV service providers need mechanisms to assess the performance requirements of the end-users before providing IPTV services. They must be able to provide a consistent and expected level of performance. Metric is important for ensuring the performance of NGN transport control functionality which is an integral part of a business process commonly referred to as service assurance (SA). Some of the responsibilities of SA include: + +- proactive and reactive maintenance to ensure that services provided to customers are continuously available and performing to service level agreements (SLA), if applicable, or QoS performance levels; +- continuous resource status and performance monitoring to proactively detect possible failures; +- collection of performance data; +- analysis of performance data to identify potential problems and resolve them without impact to the end-user; +- if applicable, managing SLAs and report service performance to the end-user; +- receiving trouble reports from the end-user and informing it of the trouble status and ensuring the end-user of restoration and repair. In other words, SA supports the following applications: + - network planning and engineering; + - service installation and provisioning; and + - management of the customer's service by supporting fault and accounting management processes. + +The detailed mechanisms for metrics measurement can be found in [b-ITU-T Y.2173]. + +### **IV.3 SLA** + +Mechanisms are required to measure the diverse aspects of SLA which include: + +- defect free forwarding (The service is considered to be available and the other aspects of performance measurement listed below have meaning, or the service is unavailable and other aspects of performance measurement do not have meaning); +- latency; + +- amount of time required for traffic to transit the network; +- packet loss; +- jitter – measurement of latency variation. + +Such measurements can be made independent of the user traffic or via a hybrid of user traffic measurement and OAM probing. At least one mechanism is required to measure the number of OAM packets. In addition, the ability to measure the qualitative aspects of user traffic such as jitter, delay, latency and loss must be available in order to determine whether or not the traffic for a specific user traffic are travelling within the operator-specified tolerances. + +### **IV.4 Policy management** + +Policies are a set of rules typically for administering, managing and controlling access to network resources. They can be specific to the needs of the service provider or reflect the agreement between the end-user and service provider, which may include reliability and availability requirements over a period of time and other QoS requirements. Policies are used to implement mechanism for service provider includes but not limited to: + +- routing policies (e.g., directing packet flow to a destination port without a routing table); +- packet filtering policies (e.g., marking or dropping packets based on a classifier policy); +- packet logging policies (e.g., allowing users to log specified packet flows); +- security related policies. + +The detailed mechanism for policy management can be found in [b-ITU-T Y.2111]. + +## Appendix V + +## Cross-layer interaction for IPTV services + +(This appendix does not form an integral part of this Recommendation.) + +Figure V.1 shows a generic layer architecture for offering of video services (not limited to the examples shown). At the application layer, video codec generates video elementary streams as a result of the encoding process. Service layer is responsible for packaging video streams into services such as broadcast video, VoD, etc. The function of the transport layer is to transport video streams from source to the destination through different network segments. + +![](474a819357587e34949a3e110ff19b30_img.jpg) + +| | | | | +|--------------------------|-----|--------------------|-----| +| Application Layer | | | | +| H.264 | | MPEG-2 | AVS | +| Service Layer | | | | +| VoD | | Broadcast Video | | +| Transport Layer | | | | +| IP | RTP | Ethernet
802.11 | | + +**Figure V.1 – Layer architecture for video transport** + +Cross-layer interaction is the ability of one layer adapting its performance based on information received from other layers. For instance, in a wireless transport environment, it may be beneficial for the application to adjust its rate based on the status of the rates that can be supported by the transport layer. Cross layer interaction may be implemented in a top-down or down-top fashion. + +The use of application layer priority to optimize transport layer performance is of particular interest. Video codecs generate video elementary streams with different priorities based on the picture type (i.e., I, P or B). Type I pictures are essential for the codec operation and should always be given transport priority over the P and B frames. MPEG-2/AVS transport stream and ITU-T H.264/AVS network adaptation layer (NAL) generate transport video stream packets with relative priority indication (one bit transport priority in the MPEG-2/AVS transport stream packet and 2 bits NAL Reference ID(NRI) in ITU-T H.264/AVS). + +## Bibliography + +- [b-ITU-T E.860] Recommendation ITU-T E.860 (2002), *Framework of a service level agreement*. +- [b-ITU-T Y.1221] Recommendation ITU-T Y.1221 (2002), *Traffic control and congestion control in IP based networks*. +- [b-ITU-T Y.2111] Recommendation ITU-T Y.2111 (2008), *Resource and admission control functions in Next Generation Networks*. +- [b-ITU-T Y.2173] Recommendation ITU-T Y.2173 (2008), *Management of performance measurement for NGN*. +- [b-ITU-T Y-Sup.5] ITU-T Y-series Recommendations – Supplement 5 (2008), *ITU-T Y.1900-series – Supplement on IPTV service use cases*. +- [b-ETSI TS 102034] ETSI TS 102034 v1.3.1 (2007), *Digital Video Broadband (DVB) Transport of MPEG-2 TS Based DVB Service over IP Based Networks*. +- [b-IEEE 802.1d] IEEE 802.1D (2004), *IEEE Standard for Local and Metropolitan Area Networks: Media Access Control (MAC) Bridge*. +- [b-IEEE 802.1q] IEEE 802.1Q (2005), *IEEE Standard for Local and Metropolitan Area Networks: Virtual Bridged Local Area Networks*. +- [b-IEEE 802.3] IEEE 802.3 (2005), *IEEE Standard for Local and Metropolitan Area Networks – Specific requirements Part 3: Carrier Sense Multiple Access with Collision Detection (CSMA/CD) Access Method and Physical Layer Specifications*. +- [b-IEEE 802.11] IEEE 802.11 (2007), *IEEE Standard for Local and Metropolitan Area Networks – Specific requirements Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications*. +- [b-IEEE 802.11e] IEEE 802.11e (2005), *IEEE Standard for Local and Metropolitan Area Networks – Specific requirements Part 11: Wireless LAN MAC and PHY specifications: Amendment 8: Medium Access Control (MAC) Quality of Service Enhancements*. +- [b-IEEE 802.11n] IEEE 802.11n (D3.00) Draft, *IEEE Standard for Local and Metropolitan Area Networks – Local and metropolitan area networks – Specific requirements – Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY)*. +- [b-IETF RFC 2205] IETF RFC 2205 (1997), *Resource ReSerVation Protocol (RSVP) – Version 1 Functional Specification*. +- [b-IETF RFC 2309] IETF RFC 2309 (1998), *Recommendations on Queue Management and Congestion Avoidance in the Internet*. +- [b-IETF RFC 2386] IETF RFC 2386 (1998), *A Framework for QoS-based Routing in the Internet*. +- [b-IETF RFC 2475] IETF RFC 2475 (1998), *An Architecture for Differentiated Services*. +- [b-IETF RFC 2597] IETF RFC 2597 (1999), *Assured Forwarding PHB Group*. + +- [b-IETF RFC 2676] IETF RFC 2676 (1999), *QoS Routing Mechanisms and OSPF Extensions*. +- [b-IETF RFC 2753] IETF RFC 2753 (2000), *A Framework for Policy-based Admission Control*. +- [b-IETF RFC 2998] IETF RFC 2998 (2000), *A Framework for Integrated Services Operation over DiffServ Networks*. +- [b-IETF RFC 3246] IETF RFC 3246 (2002), *An Expedited Forwarding PHB (Per-Hop Behavior)*. +- [b-IETF RFC 3272] IETF RFC 3272 (2002), *Overview and Principles of Internet Traffic Engineering*. +- [b-IETF RFC 4594] IETF RFC 4594 (2006), *Configuration Guidelines for DiffServ Service Classes*. +- [b-HGI] Home Gateway Initiatives (2006), *Home Gateway Technical Requirements: Release 1*. + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|--------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Terminals and subjective and objective assessment methods | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/Y/T-REC-Y.1991-201003-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg b/marked/Y/T-REC-Y.1991-201003-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..605056e7d2352e77b6fdc2b2876e0a74a5455f4b --- /dev/null +++ b/marked/Y/T-REC-Y.1991-201003-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:8a3b4d3bfe54a3c1c5d1d141685878db3714fad147735036131d49e5fbf67289 +size 7464 diff --git a/marked/Y/T-REC-Y.1991-201003-I_PDF-E/raw.md b/marked/Y/T-REC-Y.1991-201003-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..f0df2a50d86482d1732ca61788cab5a8ef9ff15e --- /dev/null +++ b/marked/Y/T-REC-Y.1991-201003-I_PDF-E/raw.md @@ -0,0 +1,942 @@ + + +I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +## Y.1991 + +(03/2010) + +SERIES Y: GLOBAL INFORMATION +INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS +AND NEXT-GENERATION NETWORKS + +Internet protocol aspects – IPTV over NGN + +# --- **Terms and definitions for IPTV** + +Recommendation ITU-T Y.1991 + +![ITU logo](84a1d09fb489061482111515543b60dc_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with a red lightning bolt striking it, and the text "ITU" in blue, with "International Telecommunication Union" written in smaller blue text below it. + +ITU logo + +# ITU-T Y-SERIES RECOMMENDATIONS **GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT- GENERATION NETWORKS** + +## GLOBAL INFORMATION INFRASTRUCTURE + +| | | +|-------------------------------------------|-------------| +| General | Y.100–Y.199 | +| Services, applications and middleware | Y.200–Y.299 | +| Network aspects | Y.300–Y.399 | +| Interfaces and protocols | Y.400–Y.499 | +| Numbering, addressing and naming | Y.500–Y.599 | +| Operation, administration and maintenance | Y.600–Y.699 | +| Security | Y.700–Y.799 | +| Performances | Y.800–Y.899 | + +## INTERNET PROTOCOL ASPECTS + +| | | +|--------------------------------------------------------------------|---------------| +| General | Y.1000–Y.1099 | +| Services and applications | Y.1100–Y.1199 | +| Architecture, access, network capabilities and resource management | Y.1200–Y.1299 | +| Transport | Y.1300–Y.1399 | +| Interworking | Y.1400–Y.1499 | +| Quality of service and network performance | Y.1500–Y.1599 | +| Signalling | Y.1600–Y.1699 | +| Operation, administration and maintenance | Y.1700–Y.1799 | +| Charging | Y.1800–Y.1899 | + +### | | | |----------------------|----------------------| | IPTV over NGN | Y.1900–Y.1999 | |----------------------|----------------------| + +## NEXT GENERATION NETWORKS + +| | | +|-------------------------------------------------------------------|---------------| +| Frameworks and functional architecture models | Y.2000–Y.2099 | +| Quality of Service and performance | Y.2100–Y.2199 | +| Service aspects: Service capabilities and service architecture | Y.2200–Y.2249 | +| Service aspects: Interoperability of services and networks in NGN | Y.2250–Y.2299 | +| Numbering, naming and addressing | Y.2300–Y.2399 | +| Network management | Y.2400–Y.2499 | +| Network control architectures and protocols | Y.2500–Y.2599 | +| Future networks | Y.2600–Y.2699 | +| Security | Y.2700–Y.2799 | +| Generalized mobility | Y.2800–Y.2899 | +| Carrier grade open environment | Y.2900–Y.2999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# **Recommendation ITU-T Y.1991** + +# **Terms and definitions for IPTV** + +## **Summary** + +Recommendation ITU-T Y.1991 contains terms and definitions and a framework relevant to providing a general understanding of IPTV. The primary purpose of this Recommendation is to provide a context for the use of certain terms and definitions to avoid misunderstandings in IPTV and IPTV-related activities. + +## **History** + +| Edition | Recommendation | Approval | Study Group | +|---------|----------------|------------|-------------| +| 1.0 | ITU-T Y.1991 | 2010-03-16 | 13 | + +### **Keywords** + +CDN, DoS, dPVR, ECG, EPG, ePVR, IPTV, metadata, nPVR, PVR, SCP, TD, VoD. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +### INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2010 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## CONTENTS + +| | Page | +|-----------------------------------------------------------------------------------------------|-------------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Terms and definitions ..... | 1 | +| 4 Abbreviations and acronyms ..... | 1 | +| 5 Conventions ..... | 1 | +| 6 IPTV definition..... | 1 | +| 7 Terms used in Recommendations related to requirements to support IPTV services.. | 1 | +| 8 Terms used in Recommendations related to IPTV architecture ..... | 5 | +| 9 Terms used in Recommendations related to performance, QoE, QoS and traffic management..... | 6 | +| 10 Terms used in Recommendations related to metadata, terminal devices and home network ..... | 6 | +| 11 Terms used in Recommendations related to secondary distribution ..... | 11 | +| 12 Terms used in Recommendations related to IPTV security aspects..... | 12 | +| Bibliography..... | 15 | +| Alphabetical index ..... | 18 | + + + +# **Recommendation ITU-T Y.1991** + +# **Terms and definitions for IPTV** + +## **1 Scope** + +This Recommendation contains terms and definitions and a framework relevant to providing a general understanding of IPTV. This Recommendation is not simply a compendium of terms and definitions. The primary purpose of this Recommendation is to provide a context for the use of certain terms and definitions to avoid misunderstandings in IPTV and IPTV-related activities. Thus, the definitions are arranged in a specific order and certain necessary relationships are illustrated. This Recommendation uses terms and definitions, which are considered particularly suitable and applicable to IPTV work and that have already been defined in published ITU-T Recommendations. + +## **2 References** + +None. + +## **3 Terms and definitions** + +Not applicable. + +## **4 Abbreviations and acronyms** + +This Recommendation uses the following abbreviation: + +IPTV Internet Protocol Television + +## **5 Conventions** + +There are no specific conventions in this Recommendation. + +## **6 IPTV definition** + +**6.1 IPTV** [b-ITU-T Y.1901]: Multimedia services such as television/video/audio/text/graphics/data delivered over IP-based networks managed to support the required level of QoS/QoE, security, interactivity and reliability. + +## **7 Terms used in Recommendations related to requirements to support IPTV services** + +**7.1 accessibility feature** [b-ITU-T Y.1901]: An additional content component that is intended to assist people hindered in their ability to perceive an aspect of the main content. Examples: captions for the hard of hearing, subtitles in various languages, sign-language interpretation video and descriptive audio. + +**7.2 acquisition** [b-ITU-T Y.1901]: The process of obtaining content by the end-user. + +NOTE – For content with accessibility features, this means that the content will be available in a form that can be used by the end-user. + +**7.3 application provider** [b-ITU-T Y-Sup.5]: The entity providing IPTV-related user applications. + +**7.4 aspect ratio** [b-ITU-T Y.1901]: The ratio of the width to the height of a rectangular area, such as the defined display area. + +**7.5 audio description** [b-ITU-T Y.1901]: This service provides a commentary describing the visual events pertinent to the content and augments the dialog in the content. + +NOTE – Audio description is primarily intended to assist users who are unable to see the video content clearly. The narrative passages fit between the dialogue and other significant audio content so as not to interfere with it. Ideally, the user can control the volume and spatial positioning of the audio or derive it from a separate output. + +**7.6 broadcast** [b-ITU-T M.60]: One-way transmission from one point to two or more other points. + +**7.7 captions** [b-ITU-T Y.1901]: Captions provide a real-time on-screen transcript of the dialogue as well as any sound effects. + +NOTE – This service can be provided by means of either textual or graphical supplementary content. The captions and the dialogue are usually in the same language. The service is primarily to assist users having difficulty hearing the sound. Ideally, users may have some control over the position and size of the presentation. Different speakers are distinguished, usually by different colours. + +**7.8 channel** [b-ITU-T Y.1901]: Content formatted as a selectable set of data and transported as part of a data stream. + +**7.9 channel changing** [b-ITU-T Y.1901]: The act of changing from one channel to another. + +**7.10 client personal video recorder (cPVR)** [b-ITU-T Y.1901]: Same as PVR except that the recording device is located at the end-user's premises. + +**7.11 content aggregator** [b-ITU-T Y-Sup.5]: A player in the IPTV service delivery chain whose role is to aggregate content, e.g., forming a TV bouquet composed of several TV channels. + +**7.12 content segment** [b-ITU-T Y.1901]: A continuous portion of a piece of content, for example, a single topic in a news programme. + +**7.13 delivery network gateway (DNG)** [b-ITU-T Y.1901]: A device implementing the DNGF. + +NOTE – DNG also is commonly referred to as the residential gateway (RG). + +**7.14 delivery network gateway functions (DNGF)** [b-ITU-T Y.1901]: Set of functions that mediate between the network and service provider domains and the IPTV terminal function (ITF). + +NOTE – A device implementing the DNGF is commonly referred to as the residential gateway (RG) or delivery network gateway (DNG). + +**7.15 end system** [b-ITU-T Y.1901]: A single or set of consumer devices that support IPTV services (e.g., delivery network gateway, display). + +**7.16 IPTV terminal device** [b-ITU-T Y.1901]: A terminal device which has ITF functionality, e.g., a STB. + +**7.17 IPTV terminal function (ITF)** [b-ITU-T Y.1901]: The end-user function(s) associated with: a) receiving and responding to network control channel messages regarding session set-up, maintenance, and tear-down; and b) receiving the content of an IP transport from the network and rendering. + +**7.18 linear TV** [b-ITU-T Y.1901]: A television service in which a continuous stream flows in real time from the service provider to the terminal device and where the user cannot control the temporal order in which contents are viewed. + +**7.19 metadata** [b-ITU-T Y.1901]: Structured, encoded data that describe characteristics of information-bearing entities to aid in the identification, discovery, assessment, and management of the described entities. + +NOTE – EPG metadata has many applications and may vary in depth from merely identifying the content package title or information to populate an EPG to providing a complete index of different scenes in a movie or providing business rules detailing how the content package may be displayed, copied, or sold. + +**7.20 middleware** [b-ITU-T Y.1901]: A layer of software between applications and resources, which consists of a set of service enablers that allow multiple functionalities running on one or more devices in an IPTV system to interact across a network. + +**7.21 mobility** [b-ITU-T Q.1706]: The ability for the user or other mobile entities to communicate and access services irrespective of changes of the location or technical environment. + +**7.22 multi-channel audio** [b-ITU-T Y.1901]: Audio signal with more than two channels. + +**7.23 network personal video recorder (nPVR)** [b-ITU-T Y.1901]: Same as PVR except that the recording device is located at the service provider premises. + +**7.24 package** [b-ITU-T Y.1901]: A collection of content components that in some combination (either all or a subset) together provide an end-user experience and are intended to be used together. + +NOTE – A package can be instantiated with or without audiovisual content depending on scenarios, in which audiovisual content and package can be tightly associated or can be loosely coupled enough to be handled (generation, delivery, consumption) independently. + +**7.25 pay per view (PPV)** [b-ITU-T Y.1901]: A TV service where a particular program event (e.g., a hockey match) can be bought separately from any package or subscription. The transmission of the program event is made at the same time to everyone who has ordered it. + +**7.26 personal video recorder (PVR)** [b-ITU-T Y.1901]: An end-user controlled device that records, stores and plays back multimedia content. PVR is also known as personal digital recorder (PDR). + +**7.27 picture-in-picture** [b-ITU-T Y.1901]: One program is displayed on the full-seized IPTV TD screen, one or more other programs are simultaneously displayed in inset windows. + +**7.28 place shifting** [b-ITU-T Y.1901]: A function which allows subscribers to see the content without place limitations. + +**7.29 push VoD** [b-ITU-T Y.1901]: A TV service where multimedia content is packaged and delivered at the discretion of the service provider to the end-user's storage system. + +**7.30 random access point** [b-ITU-T Y.1901]: A point in the content from which playback can begin. + +NOTE – For example, in MPEG encoding, this would be an I-frame, as opposed to a P-frame or B-frame. + +**7.31 re-transmission broadcast service** [b-ITU-T Y.1901]: A service in which content is provided from various broadcasting environments including, but not limited to, terrestrial, satellite and cable, and re-transmitted into IP network simultaneously or otherwise. + +**7.32 service** [b-ITU-T Y.1901]: A set of functionalities enabled by a provider for end-users. + +NOTE – Example provisioned functionalities include IP connectivity with managed quality of service, video-on-demand. + +**7.33 service provider** [b-ITU-T M.1400]: A general reference to an operator that provides telecommunication services to customers and other users either on a tariff or contract basis. A service provider may or may not operate a network. A service provider may or may not be a customer of another service provider. + +NOTE – Typically, the service provider acquires or licenses content from content providers and packages this into a service that is consumed by the end-user. + +**7.34 sign language interpretation** [b-ITU-T Y.1901]: A video service showing an interpreter who uses hand gestures and facial expression to convey the main audio content and dialogue to sign language and lip readers. + +NOTE – This service comes in the form of supplementary video content, usually smaller in image size to that of the main video content. Ideally, the user can control the position, size and background properties (solid or transparent and the colour, if solid). It is of sufficient temporal and spatial quality to enable sign reading and lip reading. + +**7.35 skin** [b-ITU-T Y.1901]: A customized graphical appearance (the visual aspect of a graphical user interface (GUI)) applied to certain software and websites for aesthetic reasons or ease of use. + +**7.36 subscriber** [b-ITU-T M.3050.1]: The subscriber is responsible for concluding contracts for the services subscribed to and for paying for these services. + +**7.37 subscription** [b-ITU-T Q.1741.3]: A subscription describes the commercial relationship between the subscriber and the service provider. + +**7.38 subtitles** [b-ITU-T Y.1901]: Subtitles provide a real-time on-screen transcript of dialogue for the purpose of language translation or to clarify speech that is unclear. + +NOTE – This service can be provided by means of either textual or graphical supplementary content. The subtitles and the dialogue are usually in different languages. The assumed audience for subtitling is hearing people who do not understand the language of the dialogue. + +**7.39 supplementary content** [b-ITU-T Y.1901]: Video, audio, textual, graphical or other forms of content that can be optionally accessed by the end-user and rendered by the terminal. It has the following features: + +- It only works in conjunction with the main content. +- It is synchronous with the main content. + +**7.40 terminal device (TD)** [b-ITU-T Y.1901]: An end-user device which typically presents and/or processes the content, such as a personal computer, a computer peripheral, a mobile device, a TV set, a monitor, a VoIP Terminal or an audiovisual media player. + +**7.41 terminal device protection** [b-ITU-T Y.1901]: Ensuring that a terminal device employed by an end-user in the reception of a service can reliably and securely use content while enforcing the rights of use granted for that content, and while physically and electronically protecting the integrity of the terminal device, and the confidentiality of the content and critical security parameters not otherwise protected by encryption or watermarking. + +**7.42 third party metadata** [b-ITU-T Y.1901]: Metadata provided by an entity (which may be a person) not directly tied to the primary service provider by whom the end-user is being served. + +**7.43 time shifting** [b-ITU-T Y.1901]: A function which allows playback of content after its initial transmission. + +**7.44 trick mode functionality** [b-ITU-T Y.1901]: The ability to pause, rewind or forward stored content. + +**7.45 TV with trick mode** [b-ITU-T Y.1901]: TV service with trick mode functionality. + +**7.46 universal design** [b-ITU-T Y.1901]: It is the design of the products and environments to be useable by all people, to the greatest extent possible by including accessibility features in the original design to prevent the need for adaptation after deployment. + +NOTE – The intent of universal design is to simplify life for everyone by making products, communications, and the built environment more usable by as many people as possible at little or no extra cost. Universal design benefits people of all ages and abilities. + +**7.47 usage environment description** [b-ITU-T Y.1901]: The usage environment description includes the description of end-user characteristics, terminal capabilities, network characteristics and natural environment characteristics. + +NOTE – These various dimensions of the usage environment description, which originate from end-users, can be used for accommodating, for example, the adaptation of contents for transmission, storage and consumption. + +**7.48 video-on-demand (VoD)** [b-ITU-T Y.1901]: A service in which the end-user can, on demand, select and view a video content and where the end-user can control the temporal order in which the video content is viewed (e.g., the ability to start the viewing, pause, fast forward, rewind, etc.) + +NOTE – The viewing may occur some time after the selection of the video content. + +**7.49 wireless network characteristics** [b-ITU-T Y.1901]: The characteristics of a wireless network expressed in terms of current available bandwidth, packet loss and possibly other wireless network information parameters for a specific wireless link type, e.g., WLAN, cellular, WPAN or WMAN. + +## **8 Terms used in Recommendations related to IPTV architecture** + +**8.1 application** [b-ITU-T Y.101]: A structured set of capabilities, which provide value-added functionality supported by one or more services. + +**8.2 content provider** [b-ITU-T Y.1910]: The entity that owns or is licensed to sell content or content assets. + +**8.3 delivery** [b-ITU-T Y.1910]: In context of IPTV architecture, "delivery" is defined as sending contents to the end-user. + +**8.4 distribution** [b-ITU-T Y.1910]: In context of IPTV architecture, "distribution" is defined as sending the content to appropriate intermediate locations to enable subsequent delivery. + +**8.5 end-user** [b-ITU-T Y.1910]: The actual user of the products or services. + +NOTE – The end-user consumes the product or service. An end-user can optionally be a subscriber. + +**8.6 functional architecture** [b-ITU-T Y.2012]: A set of functional entities and the reference points between them used to describe the structure of an NGN. These functional entities are separated by reference points, and thus, they define the distribution of functions. + +NOTE 1 – The functional entities can be used to describe a set of reference configurations. These reference configurations identify which reference points are visible at the boundaries of equipment implementations and between administrative domains. + +NOTE 2 – This definition is taken from [b-ITU-T Y.2012] and therefore relates to NGN. However, it is also valid for other networks, e.g., networks supporting IPTV. + +**8.7 functional entity** [b-ITU-T Y.2012]: An entity that comprises an indivisible set of specific functions. Functional entities are logical concepts, while groupings of functional entities are used to describe practical, physical implementations. + +**8.8 network provider** [b-ITU-T Y.1910]: The organization that maintains and operates the network components required for IPTV functionality. + +NOTE 1 – A network provider can optionally also act as service provider. + +NOTE 2 – Although considered as two separate entities, the service provider and the network provider can optionally be one organizational entity. + +**8.9 reference point** [b-ITU-T Y.2012]: A conceptual point at the conjunction of two non-overlapping functional entities that can be used to identify the type of information passing between these functional entities. + +NOTE – A reference point corresponds to one or more physical interfaces between pieces of equipment. + +## **9 Terms used in Recommendations related to performance, QoE, QoS and traffic management** + +**9.1 channel zapping** [b-ITU-T G.1080]: The act of quickly changing from one channel to another. + +**9.2 clean audio** [b-ITU-T G.1080]: Audio track of an IPTV service with background sounds removed. + +**9.3 group of pictures** [b-ITU-T G.1080]: The group of pictures (GOP) is a group of successive pictures within a MPEG-coded film and/or video stream. Each MPEG-coded film and/or video stream consists of successive GOPs. From the MPEG pictures contained in it, the visible frames are generated. + +**9.4 platform** [b-ITU-T G.1081]: A hardware and/or software architecture that serves as a foundation or base for realizing certain functionality. + +**9.5 quality of experience (QoE)** [b-ITU-T P.10 Amd.2]: The overall acceptability of an application or service, as perceived subjectively by the end-user. + +NOTE 1 – Quality of Experience includes the complete end-to-end system effects (client, terminal, network, services infrastructure, etc.). + +NOTE 2 – Overall acceptability may be influenced by user expectations and context. + +**9.6 triple play services** [b-ITU-T G.1080]: Services that include IPTV, VoIP, and Internet access. + +**9.7 VoD trick modes** [b-ITU-T G.1080]: Download and streaming video on demand (VoD) systems provide the user with a large subset of VCR functionality including pause, fast forward, fast rewind, slow forward, slow rewind, jump to previous/future frame, etc. These functions are usually referred to as "trick modes". + +## **10 Terms used in Recommendations related to metadata, terminal devices and home network** + +**10.1 application environment** [b-ITU-T J.200]: The context or software environment in which an application is processed. + +**10.2 application event** [b-ITU-T H.740]: An application event is every user interaction or occurrence related with multimedia contents in IPTV applications. It includes an emergency event from event notification services. + +**10.3 application programming interface (API)** [b-ITU-T J.200]: Consists of software libraries that provide uniform access to system services. + +**10.4 audience measurement** [b-ITU-T H.740]: Measuring how many people are in an audience, usually in relation to television viewership, but also newspaper and magazine readership, and increasingly, usage of websites and IPTV service. + +NOTE – Measurement may include demographic (e.g., age, gender) and sometimes psychographic information (e.g., personality, values, attitude, interests, lifestyles), to help broadcasters and advertisers determine who is listening, rather than just how many. + +**10.5 author** [b-ITU-T H.761]: Person who writes NCL documents. + +**10.6 authoring tool** [b-ITU-T H.761]: Tool to help authors to create NCL documents. + +**10.7 broadcast markup language (BML)** [b-ARIB STD B-24]: The XML application language specified in [b-ARIB STD B-24] to be solely responsible for tags and attributes for multimedia representation. + +**10.8 certificate revocation list (CRL)** [b-ITU-T X.509]: A signed list indicating a set of certificates that are no longer considered valid by the certificate issuer. In addition to the generic term CRL, some specific CRL types are defined for CRLs that cover particular scopes. + +**10.9 character** [b-ITU-T J.200]: A specific "letter" or other identifiable symbol, e.g., "A". + +**10.10 content** [b-ITU-T T.174]: Encoded generic value, media or non-media data. + +**10.11 content delivery network (CDN)** [b-ITU-T F.750]: A network optimized for delivering digital content. + +**10.12 data carousel** [b-ITU-T J.200]: A transmission scheme defined in ISO/IEC 13818-6, with which data is transmitted repetitively. It can be used for downloading various data in broadcasting. The scenario of the DSM-CC User-to-Network Download protocol that embodies the cyclic transmission of data. + +**10.13 declarative application** [b-ITU-T J.200]: An application which primarily makes use of declarative information to express its behaviour; an XML document instance is an example of a declarative application. + +**10.14 declarative application environment** [b-ITU-T J.200]: An environment that supports the processing of declarative applications; an XML user agent (browser) is an example of a declarative application environment. + +**10.15 digital storage media command and control (DSM-CC)** [b-ITU-T J.200]: A control method defined in ISO/IEC 13818-6, which provides access to files or streams for digital interactive services. + +**10.16 distributed PVR (dPVR)** [b-ITU-T H.720]: Multiple instances of PVR, where a combination of cPVRs and nPVRs can be used to record and store video, audio and other associated data for subsequent playback. For example, this usually occurs within a home network containing multiple cPVRs in order to distribute storage of video, audio and other data. + +**10.17 ECMAScript** [b-ISO/IEC 16262]: The programming language defined by Standard ISO/IEC 16262. + +**10.18 electronic content guide (ECG)** [b-ITU-T H.721]: A service navigation application used especially for streamed and downloaded content. ECG deals with metadata unlike service information used in terrestrial broadcasting. + +**10.19 electronic program guide (EPG)** [b-ITU-T H.721]: A service navigation interface which is used especially for programs. + +NOTE – In some traditional broadcast services, EPG is defined as an on-screen guide used to display information on scheduled live broadcast television programs, allowing a viewer to navigate, select, and discover programs by time, title, channel, genre. This traditional definition does not cover "catalogues" for on-demand and download services (sometimes called ECG) and bidirectional interactive service (sometimes called IPG) for end-user interaction with a server or head-end. Some EPGs utilize web-pages, or teletext to realize this function. + +**10.20 element** [b-ITU-T J.200]: A portion of document punctuated by tags. + +**10.21 elementary stream (ES)** [b-ITU-T H.222.0]: A generic term for one of the coded video, coded audio or other coded bit streams in PES packets. One elementary stream is carried in a sequence of PES packets with one, and only one, stream id. + +**10.22 EPG provider** [b-ITU-T J.90]: The entity that collects, collates and assembles the elements of information that constitute the EPG database. + +**10.23 event** [b-ITU-T H.761]: Occurrence in time that may be instantaneous or have a measurable duration. + +**10.24 execution engine** [b-ITU-T J.200]: A subsystem in a receiver that evaluates and executes procedural applications consisting of computer language instructions and associated data and media content. An execution engine may be implemented with an operating system, computer language compilers, interpreters, and Application Interfaces (APIs), which a procedural application may use to present audiovisual content, interact with a user, or execute other tasks, which are not evident to the user. A common example of an execution engine is the JavaTV software environment, using the Java programming language and byte code interpreter, JavaTV APIs, and a Java Virtual Machine for program execution. + +**10.25 forward error correction (FEC)** [b-ITU-T H.701]: FEC-based CDER mechanisms generate redundant data to allow the IPTV terminal to correct packet losses. With this redundant information, the receivers can recover from packet losses locally at the IPTV terminal. + +**10.26 FEC base layer** [b-ITU-T H.701]: Most important FEC layer. In the context of this Recommendation, this refers to the base layer in the FEC as specified in ETSI TS 102 034. + +**10.27 FEC enhancement layers** [b-ITU-T H.701]: Subsequent FEC layers. In the context of this Recommendation, this refers to the enhancement layers in the FEC as specified in ETSI TS 102 034. + +**10.28 FEC layer** [b-ITU-T H.701]: One FEC stream of multiple ordered FEC streams where support of this layer means that all FEC streams with more important order are also supported. + +**10.29 FEC stream** [b-ITU-T H.701]: IP packet stream associated with a media stream that contains redundant data to reconstruct a media stream locally at the IPTV terminal. + +**10.30 home network (HN)** [b-ITU-T H.622]: A home network is the collection of elements that process, manage, transport and store information, thus enabling the connection and integration of multiple computing, control, monitoring, communication and entertainment devices in the home. + +**10.31 home network (HN) capable IPTV TD** [b-ITU-T H.622.1]: An IPTV TD which has HN capability. This is typically a server and/or a client to HN devices. + +**10.32 home network (HN) capable TD** [b-ITU-T H.622.1]: A TD which has HN capability. This is typically a server and/or a client to HN devices. + +**10.33 hybrid application** [b-ITU-T H.761]: Hybrid declarative application or a hybrid imperative application. + +**10.34 hybrid declarative application** [b-ITU-T H.761]: Declarative application that makes use of imperative object content. + +NOTE – An NCL document with an embedded Java Xlet is an example of a hybrid declarative application. + +**10.35 hybrid imperative application** [b-ITU-T H.761]: Imperative application that makes use of declarative content. + +NOTE – A Java Xlet that creates and causes the display of an NCL document instance is an example of a hybrid imperative application. + +**10.36 imperative application** [b-ITU-T H.761]: Application that is started by, and primarily makes use of, imperative information to express its behaviour. + +NOTE – A Java program and a Lua program are examples of imperative applications. + +**10.37 imperative application environment** [b-ITU-T H.761]: Environment that supports the processing of imperative applications. + +**10.38 imperative object content** [b-ITU-T H.761]: Type of content that takes the form of an executable program. + +NOTE – A compiled Java Xlet is an example of imperative object content. A Lua script is another example. + +**10.39 IPTV end system (IES)** [b-ITU-T H.720]: A single or set of consumer devices that support IPTV services (i.e., everything from gateway to display). + +**10.40 IPTV network** [b-ITU-T H.720]: An entity encompassing the full group of IPTV architecture functions expected to be within the network provider and service provider functional domains. + +**10.41 IPTV TD-basic model** [b-ITU-T H.721]: IPTV basic model terminal device as defined in [b-ITU-T H.721]. + +**10.42 locator** [b-ITU-T H.761]: A link, expressed in the syntax in RFC 2396, which provides a reference to an application or resource. + +**10.43 markup language** [b-ITU-T J.200]: A formalism that describes a document's structure, appearance, or other aspects. An example of a markup language is XHTML. + +**10.44 media object** [b-ITU-T H.761]: Collection of named pieces of data that may represent a media content or a program written in a specific language. + +**10.45 media player** [b-ITU-T H.761]: Identifiable component of an application environment which decodes or executes a specific content type. + +**10.46 metadata fragments** [b-ITU-T H.750]: A metadata fragment is a self-consistent atomic portion of a metadata instance. In this context, self-consistency means that fragments can be obtained in a random order and each fragment can be transmitted and updated independently. + +**10.47 metadata instance** [b-ITU-T H.750]: A metadata instance is the data instance describing the instance of content or user, etc. A metadata instance has its data model defined by corresponding metadata schema. + +**10.48 metadata schema** [b-ITU-T H.750]: A metadata schema is the representation format for specifying data model describing target instance. + +**10.49 multimedia** [b-ITU-T J.148]: The combination of multiple forms of media such as audio, video, text, graphics, fax, and telephony in the communication of information. + +**10.50 native application** [b-ITU-T H.761]: An intrinsic function implemented by a receiver platform. + +NOTE – A closed captioning display is an example of a native application. + +**10.51 NCL content** [b-ITU-T H.761]: Set of information that consists of an NCL document and a group of data including objects (media or execution objects) accompanying the NCL document. + +**10.52 NCL formatter** [b-ITU-T H.761]: Software component that is in charge of receiving the specification of an NCL document and controlling its presentation, trying to guarantee that author-specified relationships among media objects are respected. + +NOTE – Document renderer, user agent, and player are other names used with the same meaning of document formatter. + +**10.53 NCL node** [b-ITU-T H.761]: Refers to a , , , or element of NCL. + +**10.54 NCL user agent** [b-ITU-T H.761]: Any program that interprets an NCL document written in the document language according to the terms of this specification. + +NOTE – A user agent may display a document, trying to guarantee that author-specified relationships among media objects are respected. It can read it aloud, cause it to be printed, convert it to another format, etc. + +**10.55 normal play time (NPT)** [b-ITU-T J.200]: The absolute temporal coordinates that represent the position in a stream at which an event occurs. + +**10.56 packet identifier (PID)** [b-ITU-T H.222.0]: A unique integer value used to identify elementary streams of a program in a single or multi-program transport stream. + +**10.57 persistent storage** [b-ITU-T J.200]: Memory available that can be read/written to by an application and may outlive the application's own life. Persistent storage can be volatile or non-volatile. + +**10.58 plug-in** [b-ITU-T J.200]: A set of functionalities that may be added to a generic platform in order to provide additional functionality. + +**10.59 portal** [b-ITU-T H.721]: A portal presents information from diverse sources in a unified manner and provides a way to attach the communication services. + +**10.60 presentation engine** [b-ITU-T J.200]: A subsystem in a receiver that evaluates and presents declarative applications consisting of content, such as audio, video, graphics, and text primarily based on presentation rules defined in the presentation engine. A presentation engine also responds to formatting information, or "markup", associated with the content, to user inputs, and to script statements, which control presentation behaviour and initiate other processes in response to user input and other events. A common example of a presentation engine is an HTML browser, capable of displaying text and graphic content formatted in HTML, with interactive behaviour programmed in ECMA script. + +**10.61 profile** [b-ITU-T H.761]: Specification for a class of capabilities providing different levels of functionality in a receiver. + +**10.62 program specific information (PSI)** [b-ITU-T H.222.0]: PSI consists of normative data which is necessary for the demultiplexing of Transport Streams and the successful regeneration of programs and is described in clause 2.4.4 of [b-ITU-T H.222.0]. + +NOTE – An example of privately defined PSI data is the non-mandatory network information table. + +**10.63 property element** [b-ITU-T H.761]: NCL element that defines a property name and its associated value. + +**10.64 receiver platform (platform)** [b-ITU-T J.200]: The receiver's hardware, operating system and native software libraries of the manufacturer's choice. + +**10.65 resource** [b-ITU-T J.200]: A network data object or a service, which is uniquely identified in a network. An application resource or environment resource. + +**10.66 retransmission** [b-ITU-T H.701]: Retransmission-based CDER mechanisms use feedback messages to recover from packet losses. + +**10.67 SCP provider** [b-ITU-T H.770]: A service provider that offers service and content protection functionalities to the other service providers. + +**10.68 scripting language** [b-ITU-T H.761]: Language used to describe an imperative object content that is embedded in NCL documents and in HTML documents. + +**10.69 service information (SI)** [b-ETSI EN 300 468]: Digital data describing the delivery system, content and scheduling/timing of broadcast data streams, etc. + +NOTE – It includes MPEG-2 PSI together with independently defined extensions. + +**10.70 service navigation** [b-ITU-T H.720]: A process of presenting information that allows the end-user to discover, select and consume services. + +**10.71 service navigation application** [b-ITU-T H.721]: A user interface (application) which is intended to provide information on available services, including content, which may be accessed by end-users for service navigation. + +**10.72 service platform** [b-ITU-T H.770]: A set of functions that facilitate telecommunication services provided by service providers. + +NOTE – In the context of IPTV services, examples of service platform functions are service authentication, content aggregation and content delivery. + +**10.73 set-top box (STB)** [b-ITU-T H.770]: A device that contains demodulator, de-multiplexer, decoder, other functionalities and interfaces related to signal reception and presentation of the distributed programme at the subscriber's site. + +**10.74 stream** [b-ITU-T J.200]: A unidirectional continuous flow of content. + +**10.75 telecommunication service** [b-ITU-T F.700]: A set of telecommunication capabilities that work in a complementary and cooperative way in order to let users perform applications. + +**10.76 timestamped transport stream (TTS)** [b-ITU-T H.721]: A packet format of the transport stream specified in [b-ARIB STD B-24], section 8.1.8, that adds a 32-bit field containing a counter value of a 27 MHz clock synchronized with the MPEG system clock to control a relative time entered into a decoder. + +**10.77 transport stream** [b-ITU-T H.222.0]: Refers to the MPEG-2 transport stream syntax for the packetization and multiplexing of video, audio, and data signals for digital broadcast systems. + +**10.78 uniform resource identifier (URI)** [b-ITU-T J.200]: An addressing method to access a resource in local storage or on the Internet. + +**10.79 usage environment** [b-ITU-T H.750]: The usage environment is described by user characteristics, terminal capabilities, network characteristics and natural environment characteristics, where the content is being consumed. + +**10.80 user device** [b-ATIS 0800002]: Also known as home network end-device (HNED), home network device (HND), consumer equipment (CE), terminal and physical device. A piece of hardware equipment running its software and attached to a home network and being identified by a GUID, e.g., a MAC address. A single device can be used by one or more users. + +**10.81 user interface (UI)** [b-ITU-T F.902]: Software and hardware components through which a user can interact with a system. + +**10.82 watermark** [b-ITU-T H.720]: Machine readable data in the form of a signal embedded in a digital media stream so as to be imperceptible to the consumer, but persistent through faithful transformations of the content. Note that this definition pertains to watermarks in the context of IPTV service and is not a universal definition of a watermark. In the IPTV context, watermarks are used to facilitate rights management and media piracy investigation. + +## **11 Terms used in Recommendations related to secondary distribution** + +**11.1 DOCSIS based CPE** [b-ITU-T J.700]: A terminal device that contains an embedded DOCSIS cable modem. Hybrid CPEs and IP-only CPEs may be DOCSIS based. + +**11.2 enhanced broadcasting** [b-ITU-T J.700]: A system that is capable of delivering broadcast programs over existing secondary distribution networks composed of HFC or FTTx with enhancements by applications and/or services transferred over IP-enabled networks. + +**11.3 hybrid CPE** [b-ITU-T J.700]: A terminal device that is capable of receiving content services over MPEG transport streams and IP. + +**11.4 IP-only CPE** [b-ITU-T J.700]: A terminal device that is capable of receiving content services over IP only. + +**11.5 MPEG transport CPE** [b-ITU-T J.700]: A terminal device that is capable of receiving content services over MPEG-2 transport streams only. + +**11.6 provisioning** [b-ITU-T M.2301]: The installation, assignment and commissioning (including bringing-into-service testing) of network resources. + +**11.7 resource abstraction/middleware interface** [b-ITU-T J.701]: An interface between the resource abstraction layer and the middleware service which encapsulates OS operations and the resources layer, and provides an abstract view of the resource layer. + +**11.8 service components** [b-ITU-T J.701]: The components that offer functionalities to any upper layers, regardless of the type of software and hardware in the resource layer. + +## **12 Terms used in Recommendations related to IPTV security aspects** + +**12.1 access control** [b-ITU-T X.800]: The prevention of unauthorized use of a resource, including the prevention of use of a resource in an unauthorized manner. + +**12.2 authentication** [b-ITU-T X.800]: See data origin authentication and peer-entity authentication. + +**12.3 authorization** [b-ITU-T X.800]: The granting of rights, which includes the granting of access based on access rights. + +**12.4 availability** [b-ITU-T X.800]: The property of being accessible and useable upon demand by an authorized entity. + +**12.5 confidentiality** [b-ITU-T X.800]: The property that information is not made available or disclosed to unauthorized individuals, entities, or processes. + +**12.6 content export** [b-ITU-T X.1191]: Process of exporting securely the IPTV content from the IPTV terminal to another terminal owned by the user entitled to use it. + +**12.7 content protection** [b-ITU-T X.1191]: Ensuring that an end user can only use the content that he/she already acquired in accordance with the rights granted to him/her by the rights holder; content protection involves protecting contents from illegal copying and distribution, interception, tampering, unauthorized use, etc. + +**12.8 content tracing** [b-ITU-T X.1191]: Process that enables the identification of the (arbitrary) origin of content and/or responsible party (e.g., end user) to facilitate the subsequent investigation in case of unauthorized use of content, e.g., content copying or redistribution. + +NOTE – Content-tracing information may be attached to content as either metadata or forensic watermark. + +**12.9 data origin authentication** [b-ITU-T X.800]: The corroboration that the source of data received is as claimed. + +**12.10 denial of service (DoS)** [b-ITU-T X.800]: The prevention of authorized access to resources or the delaying of time-critical operations. + +**12.11 digital signature** [b-ITU-T X.800]: Data appended to, or a cryptographic transformation (see cryptography) of a data unit that allows a recipient of the data unit to prove the source and integrity of the data unit and protect against forgery, e.g., by the recipient. + +**12.12 entitlements** [b-ITU-T X.1191]: Referring to the authorization level(s) including conditional access information that can be used by a subscriber to access certain IPTV services in his/her IPTV TD. + +**12.13 integrity** [b-ITU-T X.800]: The property that data has not been altered or destroyed in an unauthorized manner. + +**12.14 IPTV terminal device (TD) protection** [b-ITU-T X.1191]: Ensuring that the TD employed by an end user in the reception of a service can reliably and securely use content, while enforcing the rights of use as granted for such content and in the course of physically and electronically protecting the integrity of TD and confidentiality of the content and critical security parameters (e.g., saved keys) that are not protected. + +**12.15 key** [b-ITU-T X.800]: A sequence of symbols that controls the operations of encipherment and decipherment. + +**12.16 key management** [b-ITU-T X.800]: The generation, storage, distribution, deletion, archiving and application of keys in accordance with a security policy. + +**12.17 masquerade** [b-ITU-T X.800]: The pretence by an entity to be a different entity. + +**12.18 metadata for watermarking facilitation** [b-ITU-T X.1191]: Metadata created to aid subsequent watermarking embedding by downstream devices. + +**12.19 peer-entity authentication** [b-ITU-T X.800]: The corroboration that a peer entity in an association is the one claimed. + +**12.20 phishing** [b-ITU-T X.1191]: Act of acquiring sensitive or personal information such as username, date of birth, or credit card details by masquerading as a trustworthy entity. + +**12.21 privacy** [b-ITU-T X.800]: The right of individuals to control or influence what information related to them may be collected and stored and by whom and to whom that information may be disclosed. + +**12.22 repudiation** [b-ITU-T X.800]: Denial by one of the entities involved in a communication of having participated in all or part of the communication. + +**12.23 rights** [b-ITU-T X.1191]: Referring to the ability to perform a predefined set of utilization functions for a content item; these utilization functions include permissions (e.g., to view/hear, copy, modify, record, excerpt, sample, keep for a certain period, distribute), restrictions (e.g., play/view/hear for multiple number times, play/view/hear for certain number of hours), and obligations (e.g., payment, content tracing) that apply to the content and provide the liberty of use as granted to the end user. + +**12.24 rights expression** [b-ITU-T X.1191]: Syntactic embodiment of rights in concrete, formal form. + +**12.25 SCP bridging** [b-ITU-T X.1191]: Service and content protection operating mode wherein two or more service and content protection systems are operational on a single device acting as a bridge between these service and content protection systems; content acquired via one service and content protection system can be accessed via another service and content protection system on the bridge according to the granted rights. + +**12.26 SCP end-to-end** [b-ITU-T X.1191]: Service and content protection operating mode wherein content is accessed or exchanged by end devices according to the granted rights using a single service and content protection system. + +**12.27 SCP interchange** [b-ITU-T X.1191]: A more general service and content protection operating mode involving two or more devices, with each device having one or more operational service and content protection systems; the content acquired by one device through one of its service and content protection systems can be securely transferred to and accessed on another device through a different service and content protection system according to the granted rights. + +**12.28 scrambling** [b-ITU-T X.1191]: Process designed to protect multimedia content; scrambling usually uses encryption technology to protect content. + +**12.29 scrambling algorithm** [b-ITU-T X.1191]: Algorithm used in a scrambling or a descrambling process. + +**12.30 secure transcodable scheme** [b-ITU-T X.1191]: A kind of a security scheme that enables the intermediate network node to perform transcoding without decryption while preserving end-to-end security; this scheme can be executed by combining scalable coding, progressive encryption, and packetizing. The secure transcodable scheme can provide both the confidentiality and message integrity/authentication. + +**12.31 security label** [b-ITU-T X.800]: The marking bound to a resource (which may be a data unit) that names or designates the security attributes of that resource. + +NOTE – The marking and/or binding may be explicit or implicit. + +**12.32 security policy** [b-ITU-T X.800]: The set of criteria for the provision of security services. + +**12.33 service and content protection (SCP)** [b-ITU-T X.1191]: A combination of service protection and content protection or the system or implementation thereof. + +**12.34 service protection** [b-ITU-T X.1191]: Ensuring that an end user can only acquire a service and the content hosted therein by extension as what he/she is entitled to receive; service protection includes protecting service from unauthorized access as IPTV contents traverse through the IPTV service connections. + +**12.35 spoofing** [b-ITU-T X.1191]: An activity wherein a forged (spoofed) source (e.g., a person or a computer program) successfully masquerades as a legitimate source by falsifying data and for the purpose of obtaining information and/or obscuring the true source so that the forged source can carry out unauthorized activities such as spreading computer malware (e.g., virus), etc. + +**12.36 tamper-resistant** [b-ITU-T X.1191]: Resistance to tampering by either the personal users/attackers of a product, package, or system with physical/software access to it. + +**12.37 threat** [b-ITU-T X.800]: A potential violation of security. + +**12.38 transcoding** [b-ITU-T X.1191]: Process of transforming multimedia content such as images, text, audio, and video from original format to a different format or quality. + +**12.39 user privacy protection** [b-ITU-T X.1191]: Ensuring that information considered to be private (or confidential) by an end user is kept confidential while remaining subject to mandatory disclosure due to legal processes. + +**12.40 video signature** [b-ITU-T X.1191]: Metadata (or visual feature) for identifying a video content; unlike watermark embedded by manipulating original video contents, video signature is extracted from a video content itself without the risk of quality deterioration. + +## Bibliography + +- [b-ITU-T F.700] Recommendation ITU-T F.700 (2000), *Framework Recommendation for multimedia services*. +- [b-ITU-T F.750] Recommendation ITU-T F.750 (2005), *Metadata framework*. +- [b-ITU-T F.902] Recommendation ITU-T F.902 (1995), *Interactive services design guidelines*. +- [b-ITU-T G.1080] Recommendation ITU-T G.1080 (2008), *Quality of experience requirements for IPTV services*. +- [b-ITU-T G.1081] Recommendation ITU-T G.1081 (2008), *Performance monitoring points for IPTV*. +- [b-ITU-T H.222.0] Recommendation ITU-T H.222.0 (2006) | ISO/IEC 13818-1:2007, *Information technology – Generic coding of moving pictures and associated audio information: Systems*. +- [b-ITU-T H.622] Recommendation ITU-T H.622 (2008), *A generic home network architecture with support for multimedia services*. +- [b-ITU-T H.622.1] Recommendation ITU-T H.622.1 (2008), *Architecture and functional requirements for home networks supporting IPTV services*. +- [b-ITU-T H.701] Recommendation ITU-T H.701 (2009), *Content delivery error recovery for IPTV services*. +- [b-ITU-T H.720] Recommendation ITU-T H.720 (2008), *Overview of IPTV terminal devices and end systems*. +- [b-ITU-T H.721] Recommendation ITU-T H.721 (2009), *IPTV terminal devices: Basic model*. +- [b-ITU-T H.740] Recommendation ITU-T H.740 (2010), *Application event handling for IPTV services*. +- [b-ITU-T H.750] Recommendation ITU-T H.750 (2008), *High-level specification of metadata for IPTV services*. +- [b-ITU-T H.761] Recommendation ITU-T H.761 (2009), *Nested context language (NCL) and Ginga-NCL for IPTV services*. +- [b-ITU-T H.762] Recommendation ITU-T H.762 (2009), *Lightweight interactive multimedia framework (LIME) for IPTV services*. +- [b-ITU-T H.770] Recommendation ITU-T H.770 (2009), *Mechanisms for service discovery and selection for IPTV services*. +- [b-ITU-T J.90] Recommendation ITU-T J.90 (2000), *Electronic programme guides for delivery by digital cable television and similar methods – Reference operating scenario and requirements*. +- [b-ITU-T J.148] Recommendation ITU-T J.148 (2003), *Requirements for an objective perceptual multimedia quality model*. +- [b-ITU-T J.183] Recommendation ITU-T J.183 (2001), *Time-division multiplexing of multiple MPEG-2 transport streams over cable television systems*. +- [b-ITU-T J.200] Recommendation ITU-T J.200 (2001), *Worldwide common core – Application environment for digital interactive television services*. + +- [b-ITU-T J.700] Recommendation ITU-T J.700 (2009), *IPTV service requirements and framework for secondary distribution.* +- [b-ITU-T J.701] Recommendation ITU-T J.701 (2008), *Broadcast-centric IPTV terminal middleware.* +- [b-ITU-T J.702] Recommendation ITU-T J.702 (2008), *Enablement of current terminal devices for the support of IPTV services.* +- [b-ITU-T M.60] Recommendation ITU-T M.60 (1993), *Maintenance terminology and definitions.* +- [b-ITU-T M.1400] Recommendation ITU-T M.1400 (2006), *Designations for interconnections among operators' networks.* +- [b-ITU-T M.2301] Recommendation ITU-T M.2301 (2002), *Performance objectives and procedures for provisioning and maintenance of IP-based networks.* +- [b-ITU-T M.3050.1] Recommendation ITU-T M.3050.1 (2007), *Enhanced Telecom Operations Map (eTOM) – The business process framework.* +- [b-ITU-T P.10 Amd.2] Recommendation ITU-T P.10/G.100 (2006) Amendment 2 (2008), *Vocabulary for performance and quality of service, plus Amd.2: New definitions for inclusion in Recommendation ITU-T P.10/G.100.* +- [b-ITU-T Q.1706] Recommendation ITU-T Q.1706/Y.2801 (2006), *Mobility management requirements for NGN.* +- [b-ITU-T Q.1741.3] Recommendation ITU-T Q.1741.3 (2003), *IMT-2000 references to release 5 of GSM evolved UMTS core network.* +- [b-ITU-T T.174] Recommendation ITU-T T.174 (1996), *Application programming interface (API) for MHEG-1.* +- [b-ITU-T X.509] Recommendation ITU-T X.509 (2005) | ISO/IEC 9594-8:2005, *Information technology – Open Systems Interconnection – The Directory: Public-key and attribute certificate frameworks.* +- [b-ITU-T X.800] Recommendation ITU-T X.800 (1991) | ISO/IEC 7498-2:1989, *Security architecture for Open Systems Interconnection for CCITT applications.* +- [b-ITU-T X.1191] Recommendation ITU-T X.1191 (2009), *Functional requirements and architecture for IPTV security aspects.* +- [b-ITU-T Y.101] Recommendation ITU-T Y.101 (2000), *Global Information Infrastructure terminology: Terms and definitions.* +- [b-ITU-T Y.1901] Recommendation ITU-T Y.1901 (2009), *Requirements for the support of IPTV services.* +- [b-ITU-T Y.1910] Recommendation ITU-T Y.1910 (2008), *IPTV functional architecture.* +- [b-ITU-T Y.2012] Recommendation ITU-T Y.2012 (2006), *Functional requirements and architecture of next generation networks.* +- [b-ITU-T Y-Sup.5] ITU-T Y-series Recommendations – Supplement 5 (2008), *ITU-T Y.1900-series – Supplement on IPTV service use cases.* +- [b-ARIB STD B-24] ARIB Standard STD B-24 Version 5.2 (2008), *Data Coding and Transmission Specification for Digital Broadcasting.* +- [b-ATIS-0800002] ATIS 0800002 (2006), *IPTV Architecture Requirements.* + +- [b-ETSI EN 300 468] ETSI EN 300 468 V1.11.1 (2010), *Digital Video Broadcasting (DVB); Specification for Service Information (SI) in DVB systems*. +- [b-ISO/IEC 16262] ISO/IEC 16262:2002, *Information technology – ECMA Script language specification*. + +## Alphabetical index + +| Definition | Clause | +|-----------------------------------------|--------| +| access control | 12.1 | +| accessibility feature | 7.1 | +| acquisition | 7.2 | +| application | 8.1 | +| application environment | 10.1 | +| application event | 10.2 | +| application programming interface (API) | 10.3 | +| application provider | 7.3 | +| aspect ratio | 7.4 | +| audience measurement | 10.4 | +| audio description | 7.5 | +| author | 10.5 | +| authoring tool | 10.6 | +| authentication | 12.2 | +| authorization | 12.3 | +| availability | 12.4 | +| broadcast | 7.6 | +| broadcast markup language (BML) | 10.7 | +| captions | 7.7 | +| certificate revocation list (CRL) | 10.8 | +| character | 10.9 | +| channel | 7.8 | +| channel changing | 7.9 | +| channel zapping | 9.1 | +| clean audio | 9.2 | +| client personal video recorder (cPVR) | 7.10 | +| confidentiality | 12.5 | +| content | 10.10 | +| content aggregator | 7.11 | +| content delivery network (CDN) | 10.11 | +| content export | 12.6 | +| content provider | 8.2 | +| content protection | 12.7 | +| content tracing | 12.8 | +| content segment | 7.12 | +| data origin authentication | 12.9 | +| data carousel | 10.12 | +| declarative application | 10.13 | + +| Definition | Clause | +|----------------------------------------------------|--------| +| declarative application environment | 10.14 | +| delivery | 8.3 | +| delivery network gateway (DNG) | 7.13 | +| delivery network gateway functions (DNGF) | 7.14 | +| denial of service (DoS) | 12.10 | +| digital signature | 12.11 | +| digital storage media command and control (DSM-CC) | 10.15 | +| distributed PVR (dPVR) | 10.16 | +| distribution | 8.4 | +| DOCSIS based CPE | 11.1 | +| ECMAScript | 10.17 | +| electronic content guide (ECG) | 10.18 | +| electronic program guide (EPG) | 10.19 | +| element | 10.20 | +| elementary stream | 10.21 | +| end system | 7.15 | +| end-user | 8.5 | +| enhanced broadcasting | 11.2 | +| entitlements | 12.12 | +| EPG provider | 10.22 | +| event | 10.23 | +| execution engine | 10.24 | +| forward error correction (FEC) | 10.25 | +| FEC base layer | 10.26 | +| FEC enhancement layers | 10.27 | +| FEC layer | 10.28 | +| FEC stream | 10.29 | +| functional architecture | 8.6 | +| functional entity | 8.7 | +| group of pictures | 9.3 | +| home network (HN) | 10.30 | +| home network (HN) capable IPTV TD | 10.31 | +| home network (HN) capable TD | 10.32 | +| hybrid application | 10.33 | +| hybrid declarative application | 10.34 | +| hybrid imperative application | 10.35 | + +| Definition | Clause | +|----------------------------------------|--------| +| hybrid CPE | 11.3 | +| imperative application | 10.36 | +| imperative application environment | 10.37 | +| imperative object content | 10.38 | +| integrity | 12.13 | +| IP-only CPE | 11.4 | +| IPTV end system (IES) | 10.39 | +| IPTV network | 10.40 | +| IPTV TD-basic model | 10.41 | +| IPTV terminal device | 7.16 | +| IPTV terminal device (TD) protection | 12.14 | +| IPTV terminal function (ITF) | 7.17 | +| key | 12.15 | +| key management | 12.16 | +| linear TV | 7.18 | +| locator | 10.42 | +| markup language | 10.43 | +| masquerade | 12.17 | +| media object | 10.44 | +| media player | 10.45 | +| metadata | 7.19 | +| metadata for watermarking facilitation | 12.18 | +| metadata fragments | 10.46 | +| metadata instance | 10.47 | +| metadata schema | 10.48 | +| middleware | 7.20 | +| mobility | 7.21 | +| MPEG transport CPE | 11.5 | +| multi-channel audio | 7.22 | +| multimedia | 10.49 | +| native application | 10.50 | +| NCL content | 10.51 | +| NCL formatter | 10.52 | +| NCL node | 10.53 | +| NCL user agent | 10.54 | +| network personal video recorder (nPVR) | 7.23 | +| network provider | 8.8 | +| normal play time (NPT) | 10.55 | +| package | 7.24 | +| packet identifier (PID) | 10.56 | +| pay per view (PPV) | 7.25 | + +| Definition | Clause | +|-------------------------------------------|--------| +| peer-entity authentication | 12.19 | +| persistent storage | 10.57 | +| personal video recorder (PVR) | 7.26 | +| phishing | 12.20 | +| picture-in-picture | 7.27 | +| place shifting | 7.28 | +| platform | 9.4 | +| plug-in | 10.58 | +| portal | 10.59 | +| presentation engine | 10.60 | +| privacy | 12.21 | +| profile | 10.61 | +| program specific information (PSI) | 10.62 | +| property element | 10.63 | +| provisioning | 11.6 | +| push VoD | 7.29 | +| quality of experience (QoE) | 9.5 | +| random access point | 7.30 | +| receiver platform (platform) | 10.64 | +| reference point | 8.9 | +| repudiation | 12.22 | +| resource | 10.65 | +| resource abstraction/middleware interface | 11.7 | +| retransmission | 10.66 | +| re-transmission broadcast service | 7.31 | +| rights | 12.23 | +| rights expression | 12.24 | +| SCP bridging | 12.25 | +| SCP end-to-end | 12.26 | +| SCP interchange | 12.27 | +| SCP provider | 10.67 | +| scrambling | 12.28 | +| scrambling algorithm | 12.29 | +| scripting language | 10.68 | +| secure transcodable scheme | 12.30 | +| security label | 12.31 | +| security policy | 12.32 | +| service | 7.32 | +| service and content protection (SCP) | 12.33 | +| service components | 11.8 | + +| Definition | Clause | +|------------------------------------|---------------| +| service information (SI) | 10.69 | +| service navigation | 10.70 | +| service navigation application | 10.71 | +| service platform | 10.72 | +| service protection | 12.34 | +| service provider | 7.33 | +| set-top-box | 10.73 | +| sign language interpretation | 7.34 | +| skin | 7.35 | +| spoofing | 12.35 | +| stream | 10.74 | +| subscriber | 7.36 | +| subscription | 7.37 | +| subtitles | 7.38 | +| supplementary content | 7.39 | +| tamper-resistant | 12.36 | +| telecommunication service | 10.75 | +| terminal device (TD) | 7.40 | +| terminal device protection | 7.41 | +| third party metadata | 7.42 | +| threat | 12.37 | +| time shifting | 7.43 | +| timestamped transport stream (TTS) | 10.76 | +| transcoding | 12.38 | +| transport stream | 10.77 | +| trick mode functionality | 7.44 | +| triple play services | 9.6 | +| TV with trick mode | 7.45 | +| uniform resource identifier (URI) | 10.78 | +| universal design | 7.46 | +| usage environment | 10.79 | +| usage environment description | 7.47 | +| user device | 10.80 | +| user interface (UI) | 10.81 | +| user privacy protection | 12.39 | +| video-on-demand (VoD) | 7.48 | +| video signature | 12.40 | +| VoD trick modes | 9.7 | +| watermark | 10.82 | +| wireless network characteristics | 7.49 | + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|--------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Terminals and subjective and objective assessment methods | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/Y/T-REC-Y.2013-200612-I_PDF-E/0b7849dae424b0dd33e6386d2384643a_img.jpg b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/0b7849dae424b0dd33e6386d2384643a_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..a83e9e17f5f3418286f0b969486020bbf742cbd9 --- /dev/null +++ b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/0b7849dae424b0dd33e6386d2384643a_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:392b0bf77f68111abfd884a6e149405c916eb110cc1d0f457f197fd39e781227 +size 69852 diff --git a/marked/Y/T-REC-Y.2013-200612-I_PDF-E/29f586959675cafdf81cf934954908eb_img.jpg b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/29f586959675cafdf81cf934954908eb_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..6157a1190fb7805db3653b08e455bdfe548fb911 --- /dev/null +++ b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/29f586959675cafdf81cf934954908eb_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:f9b878bfe48be9cd86d6aeac74e6c08f59d113b7fb9cdba4ad73578b8377ab68 +size 21968 diff --git a/marked/Y/T-REC-Y.2013-200612-I_PDF-E/51db757d054ce1ce83c436a3578b56ca_img.jpg b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/51db757d054ce1ce83c436a3578b56ca_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..383ad78b0194c64117791993635fdf048a2e988a --- /dev/null +++ b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/51db757d054ce1ce83c436a3578b56ca_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:34642780b2f7410d3319399e64daf8d168220e4634693af71df30e4927cb06e1 +size 117322 diff --git a/marked/Y/T-REC-Y.2013-200612-I_PDF-E/5eb69662cc4fa7d0d49b4eb22951c204_img.jpg b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/5eb69662cc4fa7d0d49b4eb22951c204_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..b2d7bedbbdb08873af08ec7d256db5c90c336d05 --- /dev/null +++ b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/5eb69662cc4fa7d0d49b4eb22951c204_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:a6eb7b4597f7752e04b8831ceeaaaf594d53596a0f089a095ef527eedd76b581 +size 140017 diff --git a/marked/Y/T-REC-Y.2013-200612-I_PDF-E/69b7bd65e85cdef6fdd7fb0a8194257c_img.jpg b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/69b7bd65e85cdef6fdd7fb0a8194257c_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..7df9b7b4932d92cd4e36cdb8a9645a521b0161a8 --- /dev/null +++ b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/69b7bd65e85cdef6fdd7fb0a8194257c_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:3520ef345c3f2f460cb9944281d126386205c3a87a109c3a5aa433874781c3fa +size 90689 diff --git a/marked/Y/T-REC-Y.2013-200612-I_PDF-E/838c31609fac483fa2c01c7896a2fd6d_img.jpg b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/838c31609fac483fa2c01c7896a2fd6d_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..18c1cebdc67a5a59722383c0695fac2295293d58 --- /dev/null +++ b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/838c31609fac483fa2c01c7896a2fd6d_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:1d5ed0d22a919fbe383a4977e201a8d96eae1c07946b13dde200ab84962473a7 +size 76869 diff --git a/marked/Y/T-REC-Y.2013-200612-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..c44ad589cd23854de0326146b710e4ea75f570c4 --- /dev/null +++ b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:03467c882a01b3f522921253c60d2961edbc1ee5739097f22bda8ac436571682 +size 8256 diff --git a/marked/Y/T-REC-Y.2013-200612-I_PDF-E/8fa679f79a1bb1f527cba9f29e784e89_img.jpg b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/8fa679f79a1bb1f527cba9f29e784e89_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..b5cf72a9c4b04bcf3a1cef098fb6e90d57b38f99 --- /dev/null +++ b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/8fa679f79a1bb1f527cba9f29e784e89_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:50277d8bbedd9497f614861b5b862ed2e88efb600c19386f65a2e35d87d1f36f +size 144835 diff --git a/marked/Y/T-REC-Y.2013-200612-I_PDF-E/9167fa5ebcb66516d1bbb421ec9bba7b_img.jpg b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/9167fa5ebcb66516d1bbb421ec9bba7b_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..0b3c613475796ffab7cb63c1be646c2c11a5a906 --- /dev/null +++ b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/9167fa5ebcb66516d1bbb421ec9bba7b_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:0a9305718c6e89b7535831a5e1e996e0b7be2b428e89e8ba4146f5b9fab9efef +size 73118 diff --git a/marked/Y/T-REC-Y.2013-200612-I_PDF-E/9a14684f8ae1345c6efea6f5994c730c_img.jpg b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/9a14684f8ae1345c6efea6f5994c730c_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..aa3d8b3a223ea8a33dfc0ee93edaf2c16b0703d8 --- /dev/null +++ b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/9a14684f8ae1345c6efea6f5994c730c_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:d0d88b1d43fc003f7a69085a6cce380874f256b7ec4e4bf3f2ecbc202be8af16 +size 107955 diff --git a/marked/Y/T-REC-Y.2013-200612-I_PDF-E/a149b400127a3e3e50b3c98d27c5935c_img.jpg b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/a149b400127a3e3e50b3c98d27c5935c_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..70a2014df9d41fd8b884c24835d7f79c4917a843 --- /dev/null +++ b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/a149b400127a3e3e50b3c98d27c5935c_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:64f8fa326eea984e4a62cb92687f7cb477f9ca582d9e1454569c85c8fd561b1f +size 48974 diff --git a/marked/Y/T-REC-Y.2013-200612-I_PDF-E/b05bae46f7079e5c9b1da38adb2319e8_img.jpg b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/b05bae46f7079e5c9b1da38adb2319e8_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..1aae113d9041bbfe27980982ecd52f5ad86c2fe2 --- /dev/null +++ b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/b05bae46f7079e5c9b1da38adb2319e8_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:7de2181fc98e43116c9a38d8b30f41db8614ab11bb8a9ba6cc0ddf1db0f242c3 +size 101254 diff --git a/marked/Y/T-REC-Y.2013-200612-I_PDF-E/c76da2d73c064464051d1583fd80bb6b_img.jpg b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/c76da2d73c064464051d1583fd80bb6b_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..688b0407e343e1709aaf4de4189a7969c797f2ea --- /dev/null +++ b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/c76da2d73c064464051d1583fd80bb6b_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:7a15c57b9cb2f829b0f246d8e5dc2f0bc05a6c4c56ada395fa15db39a0778049 +size 111887 diff --git a/marked/Y/T-REC-Y.2013-200612-I_PDF-E/c914f51f4427bc672dd0526cfc90ebe9_img.jpg b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/c914f51f4427bc672dd0526cfc90ebe9_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..928fbd9eb2a02a733bee232d35df2451609e2634 --- /dev/null +++ b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/c914f51f4427bc672dd0526cfc90ebe9_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:01862248f466d336d76a4250e3f0a99e5732b320dbbbe2cdf6cdd52d29208295 +size 184270 diff --git a/marked/Y/T-REC-Y.2013-200612-I_PDF-E/cbdfdade780e677eb1c1aef3081ce9ef_img.jpg b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/cbdfdade780e677eb1c1aef3081ce9ef_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..1d4ac73750d6fd7bb5c536868e682baa85fb2c79 --- /dev/null +++ b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/cbdfdade780e677eb1c1aef3081ce9ef_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:2e3e5dcc52ac11871d0793c41ae703ac2eec097873155e6943d855a61ad514f6 +size 87622 diff --git a/marked/Y/T-REC-Y.2013-200612-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..e2a967a19066dd0770684c8416f62171a0e05902 --- /dev/null +++ b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:8eb4cf2d89a114345d5370dfd461536c3369f3bf0331be980c594315518db2d7 +size 28926 diff --git a/marked/Y/T-REC-Y.2013-200612-I_PDF-E/dcb5711d118ae6753b0e12f86eda37db_img.jpg b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/dcb5711d118ae6753b0e12f86eda37db_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..d6846bd8e320a22df06fb147cb355ace64705403 --- /dev/null +++ b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/dcb5711d118ae6753b0e12f86eda37db_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:fd5e16fb24ffce9b92bcd05d023f0f6487b0c2a3786579a63f82a5b1b016c49b +size 79255 diff --git a/marked/Y/T-REC-Y.2013-200612-I_PDF-E/e05b36c0d46549e681ce6581422c66b2_img.jpg b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/e05b36c0d46549e681ce6581422c66b2_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..054aa1c4067ec7070bddebcb8230d62b15063dc3 --- /dev/null +++ b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/e05b36c0d46549e681ce6581422c66b2_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:66ec6ab36561b3c4cebefda160af20e69061cbdd9fa3f7dc00a10f0b2e442d33 +size 67724 diff --git a/marked/Y/T-REC-Y.2013-200612-I_PDF-E/e64c7b989e5bdb2708cd7aefd18b06e1_img.jpg b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/e64c7b989e5bdb2708cd7aefd18b06e1_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..5b10029da077da2291a4b10e43f0895aa4b6d18e --- /dev/null +++ b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/e64c7b989e5bdb2708cd7aefd18b06e1_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:7bb4ecf0c82acb405ce301a05a499a9567d52d6797e1e0c3f4797902e3a4824a +size 112781 diff --git a/marked/Y/T-REC-Y.2013-200612-I_PDF-E/e97d663314aff9c29bf8971323e6539e_img.jpg b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/e97d663314aff9c29bf8971323e6539e_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..143ebc427a72da2770a6442fae5db063b555e9bd --- /dev/null +++ b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/e97d663314aff9c29bf8971323e6539e_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:1ebd3ad634e05f76073db50366cf6c714218e8d3aa9afa158b5ae8ffbf16fc06 +size 65392 diff --git a/marked/Y/T-REC-Y.2013-200612-I_PDF-E/f57c7b37d7a05a99618104f390089f03_img.jpg b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/f57c7b37d7a05a99618104f390089f03_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..c1e8c35314a801d22360ce3ccc67f265552a7827 --- /dev/null +++ b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/f57c7b37d7a05a99618104f390089f03_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:66e9676cb59545f2ac280c909ec48988680f5684e4a27568f4609ab9f0e6ad7a +size 114310 diff --git a/marked/Y/T-REC-Y.2013-200612-I_PDF-E/raw.md b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..5b059fd26e3a40341ac966a12af7df7ed78fde95 --- /dev/null +++ b/marked/Y/T-REC-Y.2013-200612-I_PDF-E/raw.md @@ -0,0 +1,1475 @@ + + +I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +# Y.2013 + +(12/2006) + +SERIES Y: GLOBAL INFORMATION +INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS +AND NEXT-GENERATION NETWORKS + +Next Generation Networks – Frameworks and functional +architecture models + +# --- **Converged services framework functional requirements and architecture** + +ITU-T Recommendation Y.2013 + +![ITU logo: A globe with a red lightning bolt and the text 'ITU International Telecommunication Union'.](84a1d09fb489061482111515543b60dc_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with a red lightning bolt striking it. To the right of the globe, the text 'ITU' is written in a large, bold, blue font, and below it, the words 'International Telecommunication Union' are written in a smaller, blue font. + +ITU logo: A globe with a red lightning bolt and the text 'ITU International Telecommunication Union'. + +## ITU-T Y-SERIES RECOMMENDATIONS GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT- GENERATION NETWORKS + +## GLOBAL INFORMATION INFRASTRUCTURE + +| | | +|-------------------------------------------|-------------| +| General | Y.100–Y.199 | +| Services, applications and middleware | Y.200–Y.299 | +| Network aspects | Y.300–Y.399 | +| Interfaces and protocols | Y.400–Y.499 | +| Numbering, addressing and naming | Y.500–Y.599 | +| Operation, administration and maintenance | Y.600–Y.699 | +| Security | Y.700–Y.799 | +| Performances | Y.800–Y.899 | + +## INTERNET PROTOCOL ASPECTS + +| | | +|--------------------------------------------------------------------|---------------| +| General | Y.1000–Y.1099 | +| Services and applications | Y.1100–Y.1199 | +| Architecture, access, network capabilities and resource management | Y.1200–Y.1299 | +| Transport | Y.1300–Y.1399 | +| Interworking | Y.1400–Y.1499 | +| Quality of service and network performance | Y.1500–Y.1599 | +| Signalling | Y.1600–Y.1699 | +| Operation, administration and maintenance | Y.1700–Y.1799 | +| Charging | Y.1800–Y.1899 | + +## NEXT GENERATION NETWORKS + +| | | +|-------------------------------------------------------------------|----------------------| +| Frameworks and functional architecture models | Y.2000–Y.2099 | +| Quality of Service and performance | Y.2100–Y.2199 | +| Service aspects: Service capabilities and service architecture | Y.2200–Y.2249 | +| Service aspects: Interoperability of services and networks in NGN | Y.2250–Y.2299 | +| Numbering, naming and addressing | Y.2300–Y.2399 | +| Network management | Y.2400–Y.2499 | +| Network control architectures and protocols | Y.2500–Y.2599 | +| Security | Y.2700–Y.2799 | +| Generalized mobility | Y.2800–Y.2899 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +## **ITU-T Recommendation Y.2013** + +# **Converged services framework functional requirements and architecture** + +## **Summary** + +This Recommendation provides the high-level requirements and functional architecture for the converged services framework (CSF). The CSF defines an architectural framework to provide a seamless user experience across multiple networks. + +###### **Source** + +ITU-T Recommendation Y.2013 was approved on 14 December 2006 by ITU-T Study Group 13 (2005-2008) under the ITU-T Recommendation A.8 procedure. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g. interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2008 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## CONTENTS + +| | Page | +|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 1 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Overview and high-level requirements..... | 3 | +| 5.1 Introduction ..... | 3 | +| 5.2 High-level requirements ..... | 3 | +| 6 CSF functional architecture and functional entities..... | 4 | +| 6.1 Convergence coordination functional entity (CC-FE) ..... | 5 | +| 6.2 Network support functional entity (NS-FE) ..... | 7 | +| 6.3 Edge support functional entity (ES-FE) ..... | 8 | +| 6.4 Client support functional entity (CLS-FE)..... | 9 | +| 6.5 Convergence policy functional entity (CP-FE) ..... | 11 | +| 7 Context of CSF within NGN ..... | 12 | +| 7.1 Relationship to NGN functional architecture ..... | 12 | +| 7.2 Service convergence types ..... | 16 | +| Appendix I – CSF use cases..... | 18 | +| I.1 Voice and presence service converged service ..... | 18 | +| I.2 Call forwarding – Video conferencing converged service ..... | 19 | +| I.3 Movement of conference call from a fixed client to mobile client ..... | 20 | +| I.4 Hybrid solution for a cross-network video + phone converged service
(video on demand point of sale service using the CSF support and
coordination functional entities)..... | 21 | +| I.5 Integrating information to improve customer service ..... | 25 | +| Appendix II – Standards related to CSF ..... | 28 | +| II.1 CSF relationship to OSA/Parlay..... | 28 | +| II.2 CSF relationship to OMA and OSE ..... | 28 | +| II.3 CSF relationship to underlying networks..... | 28 | +| Appendix III – Examples of three converged service types ..... | 30 | +| III.1 Type 1 example: Converged service in a single service component..... | 30 | +| III.2 Type 2 example: Converged service in multiple service components
(PIEA + IMS) ..... | 31 | +| III.3 Type 3 example: Converged service with other network – IMS + Internet
IM server ..... | 32 | + +| | Page | +|-------------------------------------------------------------------|-------------| +| Appendix IV – CC-FE to CC-FE interworking description models..... | 35 | +| IV.1    Hierarchical convergence model ..... | 35 | +| IV.2    Master-slave convergence model ..... | 35 | +| IV.3    Peer-to-peer convergence model ..... | 36 | +| Appendix V – CSF configuration models..... | 37 | +| Bibliography..... | 39 | + +# ITU-T Recommendation Y.2013 + +# Converged services framework functional requirements and architecture + +# 1 Scope + +One objective of NGN is to enable seamless delivery of services across users' multiple devices served across different environments (home, cellular, enterprise, etc.) that are connected across multiple access networks in one operator domain or different operator domains. As users move across different environments, their services are managed and delivered to them seamlessly and with ease. The converged services framework (CSF) is designed to provide a common point of coordination for services, mobility, preferences, resources and the state of users on a per-user basis. + +This Recommendation defines the high-level requirements and functional architecture for the CSF. In addition, this Recommendation provides example use case scenarios (see Appendix I) to highlight the functionality of the CSF. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- | | | +|----------------|------------------------------------------------------------------------------------------------------------| +| [ITU-T M.60] | ITU-T Recommendation M.60 (1993), Maintenance terminology and definitions . | +| [ITU-T Y.2012] | ITU-T Recommendation Y.2012 (2006), Functional requirements and architecture of the NGN release 1 . | +| [ITU-T Y.2021] | ITU-T Recommendation Y.2021 (2006), IMS for Next Generation Networks . | +| [ITU-T Y.2091] | ITU-T Recommendation Y.2091 (2007), Terms and definitions for Next Generation Networks . | + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +- 3.1.1 service:** [ITU-T Y.2091] A set of functions and facilities offered to a user by a provider. + +## 3.2 Terms defined in this Recommendation + +This Recommendation defines the following terms: + +- 3.2.1 application:** A software entity residing on an application server that contributes to the delivery of an end user service. + +- 3.2.2 application server:** A physical network element that provides computing resources that are applied to the delivery of services to end users through the execution of applications. + +**3.2.3 policy:** An ordered combination of policy rules that defines how to administer, manage and control access to resources. This function is responsible for policy access, policy condition matching and corresponding policy decisions according to matched conditions. + +**3.2.4 policy management:** This provides the functions for describing, creating, updating, deleting, provisioning and viewing of policies. + +**3.2.5 service convergence:** The coordination of a set of services such that the end user's view is that of a single service. The component services may have different providers. + +# **4 Abbreviations and acronyms** + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|--------|----------------------------------------------| +| a.k.a. | also known as | +| AAA | Authentication, Authorization and Accounting | +| AM | (PCMM) Application Manager | +| AS | (IMS) Application Server | +| AS-FE | Application Support Functional Entity | +| CSF | Converged Services Framework | +| CC-FE | Convergence Coordination Functional Entity | +| CLS-FE | Client Support Functional Entity | +| CP-FE | Convergence Policy Functional Entity | +| DRM | Digital Rights Management | +| ES-FE | Edge Support Functional Entity | +| FE | Functional Entity | +| GPS | Global Positioning System | +| HSS | (IMS) Home Subscriber Server | +| iFC | initial Filter Criteria | +| IMS | IP Multimedia Subsystem | +| ISC | IMS Service Control | +| ISDN | Integrated Services Digital Network | +| NGN | Next Generation Network | +| NS-FE | Network Support Functional Entity | +| OSA | Open Service Access | +| OSE | OMA Service Environment | +| OSI | Open Systems Interconnection | +| PCMM | PacketCable Multimedia | +| PIEA | PSTN/ISDN Emulation Architecture | +| POD | Point Of Display | +| PS | (PCMM) Policy Server | +| PSTN | Public Switched Telephone Network | + +| | | +|--------|-------------------------------------------| +| RKS | (PacketCable) Record Keeping Server | +| SCP | Service Control Point | +| SIP | Session Initiation Protocol | +| SLF | (IMS) Subscription Locator Function | +| SPT | (IMS) Service Point Trigger | +| SSP | Service Switching Point | +| STB | Set Top Box | +| STP | Signalling Transfer Point | +| SUP-FE | Subscriber User Profile Functional Entity | +| UE | User Equipment | +| UPnP | Universal Plug and Play | +| VoD | Video on Demand | +| WMAN | Wireless Metropolitan Area Network | + +# **5 Overview and high-level requirements** + +## **5.1 Introduction** + +The main goal of the 'converged services framework' (CSF) is to provide the experience of a service that operates smoothly and consistently when crossing the boundaries of multiple access and core networks, or when service interaction events occur. To enable this, the framework should support features common to many applications. These include tracking the user state and profile, device identity, state and profile, session state and location across multiple NGN and non-NGN networks. + +Another key element of the CSF is that it will allow advanced services to be made available to legacy terminals. + +## **5.2 High-level requirements** + +The CSF is required to support the following high-level requirements: + +- 1) Function across various transport and control networks. +- 2) Integrate user preferences and current state for each active user identifier such that the user is not required to explicitly initiate session mobility. +- 3) Collect user-related information from services, core networks, access networks, devices and applications, subject to privacy and security considerations. +- 4) Process user- and service-related information about a particular user across multiple networks, devices and applications. +- 5) Distribute processed user-related information to services, core networks, access networks, devices and applications, subject to privacy and security considerations. +- 6) Respond to service requests by end users or applications with responses that consider the processed information about a user and his/her state (for example, multiple networks, devices, applications). +- 7) Provide network-specific, application-specific or device-specific translated service requests on behalf of a received service request to allow an end user or network-agnostic application to achieve consistent behaviour across service provider domains. + +- 8) Integrate end user identifiers and preferences to create appropriate services' behaviour for the currently "in use" identifier. +- 9) Enable services that allow an end user to cause their current session to be transferred from one device to another, by user profile preference or user action. +- 10) Enable services to be converged across various transport and control networks. +- 11) Support both network-operator-specific and third-party services. +- 12) Support management of user profile, location, presence, availability, preference and service subscription information that spans different networks and devices, subject to privacy and security considerations. +- 13) Provide controlled access to information from services enablers (such as presence, availability, location, registration status, QoS options, media resources, billing) irrespective of the access network, application server and device to create enhanced integrated services on a per-user basis. +- 14) Be compliant with policy-based service management. +- 15) Support policy management of service convergence that is independent of the implementation method of the service. +- 16) Support digital rights management (DRM) and allow service providers to enable DRM when sharing content across multiple devices owned by the same user, across multiple access networks and across multiple identities of the same user. +- 17) Support the use of network adapters which allow information to be successfully delivered across an interface between systems using different data formats and protocols. +- 18) Support a flexible trace mechanism in order to locate service faults effectively. +- 19) Coordinate between services provided to a user, possibly by different service providers, such that their delivery to the user is in compliance with service provider policies and user preferences. + +Additionally, the CSF: + +- 1) should operate over access networks and NGN domains that are not controlled or managed by the CSF; and +- 2) should provide controlled access to network resources when the business agreement permits, regardless of which network the resource resides within. + +# **6 CSF functional architecture and functional entities** + +Figure 6-1 shows the CSF functional architecture, comprised of the CSF functional entities, reference points among the CSF functional entities and between CSF and the converged services/applications that rely upon CSF. + +![Figure 6-1 – CSF functional architecture diagram. The diagram shows a central CC-FE box connected to several other boxes: ES-FE (top), CP-FE (top right), NS-FE (bottom), and another CC-FE (bottom right). A CLS-FE box is on the left, with a self-loop arrow labeled I_CL-CL. A vertical box on the right is labeled 'Converged services/applications'. Reference points are labeled: I_CL-CL (between CLS-FE and ES-FE), I_C-E (between ES-FE and CC-FE), I_C-P (between CP-FE and CC-FE), I_C-CL (between CLS-FE and CC-FE), I_C-AS (between CC-FE and the 'Converged services/applications' box), I_C-N (between NS-FE and CC-FE), and I_C-C (between CC-FE and the bottom CC-FE). The identifier Y.2013(06)_F6-1 is at the bottom right.](cfef993dcc8fb513de79eb1f93cf26ae_img.jpg) + +Figure 6-1 – CSF functional architecture diagram. The diagram shows a central CC-FE box connected to several other boxes: ES-FE (top), CP-FE (top right), NS-FE (bottom), and another CC-FE (bottom right). A CLS-FE box is on the left, with a self-loop arrow labeled I\_CL-CL. A vertical box on the right is labeled 'Converged services/applications'. Reference points are labeled: I\_CL-CL (between CLS-FE and ES-FE), I\_C-E (between ES-FE and CC-FE), I\_C-P (between CP-FE and CC-FE), I\_C-CL (between CLS-FE and CC-FE), I\_C-AS (between CC-FE and the 'Converged services/applications' box), I\_C-N (between NS-FE and CC-FE), and I\_C-C (between CC-FE and the bottom CC-FE). The identifier Y.2013(06)\_F6-1 is at the bottom right. + +**Figure 6-1 – CSF functional architecture** + +NOTE 1 – The "converged services/applications" box is representing the collection of FEs in support of services and applications provided to the end user. Typically, these would correspond in an NGN environment to the FEs defined in clause 9.3.4 of [ITU-T Y.2012] ("Application support functions and Service support functions"). + +NOTE 2 – The $I_{C-AS}$ reference point is meant to represent the individual reference points between the CC-FE and any of the FEs pertaining to the "converged services/applications" box (also referred to as the "AS-FE (and similar FEs)" in this Recommendation). + +The CSF functional entities identified in Figure 6-1 are individually described in the following sub-clauses in terms of supported functions, supported reference points, actions performed as well as supported information. + +## 6.1 Convergence coordination functional entity (CC-FE) + +The convergence coordination functional entity (CC-FE) provides coordination of information about: users, devices, service subscriptions, session management and resource capabilities. The CC-FE takes input from service provider application servers/databases, profile information and/or from the network, edge, client and policy support functional entities in a single network domain or over multiple network domains. + +### 6.1.1 Reference points + +The CC-FE supports the following CSF reference points: + +- $I_{C-AS}$ , with respect to the AS-FE (and similar FEs). This reference point provides a communication path between the application server and the CSF. Some candidate protocols for this reference point are, for instance, Parlay X and SIP. If $I_{C-AS}$ is based on the IMS services control (ISC) SIP messaging set, SIP messages arriving from the AS-FE (and similar FEs) or the NS-FE are evaluated against the CC-FE user preferences for possible action. +- $I_{C-CL}$ , with respect to the CSF client support function (CLS-FE). This reference point should provide a communication path between the end user device and the CC-FE. $I_{C-CL}$ may transfer client environment information to CC-FE, such as the location of the device. In addition, other CSF-enabled devices with which the client device has communications, and other sessions the client device is participating in, may effect the CC-FE's service coordination decisions. For example, multi-interface devices may be participating in more than one session at a time, so there may be separate CC-FEs (or equivalents) for each session, see $I_{C-C}$ below. +- $I_{C-N}$ , with respect to the CSF NS-FE. This reference point should provide a communication path between a supporting underlying network and the CC-FE. $I_{C-N}$ is the main connection to the "enabling" services of the network, for example location, session control and user + +data (as stored in the HSS). $I_{C-N}$ will be implemented over several existing interfaces to existing "enablers" such as ISC to the session control. + +- $I_{C-E}$ , with respect to the CSF ES-FE. This reference point provides a communication path between a supporting edge device or network and the CC-FE. Edge devices are those network components between a customer premise and an access network. +- $I_{C-C}$ , the reference point between CC-FEs in different domains. This reference point provides a communication path between CC-FEs, each of which covers and coordinates different service providers or administration domains, etc. With this reference point, it is possible to provide coordination of multiple services of various integration types, such as hierarchical, master-slave and peer-to-peer coordination models. The examples for each model are described in Appendix IV. +- $I_{C-P}$ , with respect to the CP-FE. This reference point provides a communication path between policy functionality and the CC-FE to enable describing, creating, updating, deleting and provisioning. + +### 6.1.2 Actions + +CC-FE's actions on receipt of stimulus across one of the reference points that it terminates can be complex and extensive. CC-FE's response to stimulus is related to the following areas of concern: + +- Active-sessions-related change. +- Client location change. +- Network equipment state or informational change. +- Session initiation or termination change. +- User preference change. +- Policy change. + +Actions associated with active sessions are signalled to the CC-FE from the serving network through the NS-FE over $I_{C-N}$ or from the AS-FE (or similar FEs) over $I_{C-AS}$ . In response to stimulus, the CC-FE will adapt the arriving information to the appropriate form, add or remove information as required of the recipient and forward the information along another of its reference points. + +Client location changes will be detected by enablers (such as a location server) in the NS-FE set or by reports from CLS-FE or ES-FE that the end user's device is present within a well known network. If there are any registered applications for location changes of the type reported, those applications will be notified. The user's presently reported location will also be updated. + +Network equipment state or informational change would be reported to CC-FE over the $I_{C-N}$ reference point. These might represent user-initiated session-related signalling (i.e., SIP session control to S-CSC-FE) or a user registration with the HSS. The CC-FE would evaluate the report based on the user's preferences for actions, and the network's rules as expressed by network policies. An end result would be appropriate messaging to applications to report session or user registration changes. + +In all cases, the CC-FE complies with both user preferences as recorded in the CC-FE user profile and operator policies as directed by CP-FE. + +The CC-FE takes simple actions when stimulated. Examples include: + +- Notify application of actions (under policies). +- Inform applications of environmental changes. +- Adapt "next application" selection based on information returned by prior application. + +For example, on receipt of "new node in local environment" information from an ES-FE (resident within a subnetwork, such as a household wireless network) the CC-FE would consult the + +user-preferred response, note the transfer of voice call services to the household fixed network and send a "location update" information to a "call forward" application to place the necessary subscriptions to the user's cellphone to activate the services. + +### **6.1.3 Information** + +The CC-FE's information contains application, network, device and user-specific entries. + +The CC-FE application information model (see [ITU-T M.60]) contains at least the following information for each application that is registered with the CC-FE: + +- Identity – how to refer to the application. +- Address – how to contact the application. +- Security – how to verify the application. +- Signalling type (some applications may be non-ISC). +- Priority/sequence within applications using the same ISC message type. +- Required information to be passed to application. +- Allowed actions by the application. + +The CC-FE network information model contains at least the following information for each network that CC-FE interacts with (represented by another CC-FE): + +- Identity – how to refer to the network. +- Address – how to contact the network's CC-FE. +- Security – information and methods to authenticate this network to the network's CC-FE. +- Signalling type. +- Network allowable requests of this network. +- Network allowable requests of the other service provider networks. + +The CC-FE user information model contains the following user profile information: + +- Identities – user's identifiers or pseudonyms in all known service provider networks. +- Devices – the users devices and the network(s) providing access ability. +- Access preferences by service type – what device or service provider network is preferred for which type of service. +- Transfer preferences – which service-initiated transfers of session types the network should make for the user (by well known location). +- Well known locations – physical locations that have special meaning to the end user (e.g., their place of residence (home), their place of employment (work), others may be added by the system or end user, as needed). + +The CC-FE device information model contains the following information for devices: + +- The devices capabilities (a device may be an assembly of several attached devices, each with different capabilities, so device capability may be nested down to non-expandable devices). +- User identifiers associated/registered to this device. The device may be shared between multiple users (e.g., household land line phone and number, TV screen, etc.). + +## **6.2 Network support functional entity (NS-FE)** + +The network support functional entity (NS-FE) provides session, access and rights information to the CC-FE. + +### 6.2.1 Reference points + +The NS-FE supports the following CSF reference point: + +- $I_{C-N}$ (see clause 6.1.1) + +$I_{C-N}$ is the CC-FE to NS-FE reference point, allowing the CC-FE to interface with the network in which the NS-FE is embedded. Examples of such reference points may include ISC to IMS S-CSCF and Sh to HSS reference points in [ITU-T Y.2021]. + +#### NS-FE to network reference points + +The NS-FE supports interfaces with the network in which the NS-FE is embedded. Interface candidates include ISC to IMS S-CSCF and Sh to HSS reference points in [ITU-T Y.2021]. + +### 6.2.2 Actions + +The NS-FE is viewed as a transparent intermediary along the existing reference points available from the service control functions. NS-FE is an architecturally necessary function only when the underlying services layer/functions are not compatible with the CC-FE expectations of $I_{C-N}$ . + +#### 6.2.3 Information + +The NS-FE retains only the information necessary to connect with the CC-FE and the underlying services entities. + +The NS-FE information model contains at least the following information for each network element that NS-FE interacts with: + +- Identity – how to refer to the network element. +- Address – where to contact the network elements. +- Security – information and methods to authenticate with the underlying network elements. +- Signalling type. + +## 6.3 Edge support functional entity (ES-FE) + +The Edge Support Functional Entity (ES-FE) provides session, access, and rights information about itself and subtending devices to the CC-FE. + +The ES-FE interfaces to some combination of the access networks and the customer local networks. It provides session, resource, and identity information about itself and subtending devices to the CC-FE. + +The ES-FE is the CSF client in a set top box or similar device, non-mobile edge of an access network device. + +### 6.3.1 Reference points + +The ES-FE supports the following CSF reference points: + +- $I_{C-E}$ (see clause 6.1.1). + +$I_{C-E}$ is the CC-FE to ES-FE reference point, providing ES-FE a means to forward information about the "edge" of the access network to the CC-FE. The CC-FE may also use $I_{C-E}$ to forward commands to the edge device related to CSF functionality. + +- $I_{CL-CL}$ . + +$I_{CL-CL}$ is a CLS-FE to CLS-FE or ES-FE reference point. $I_{CL-CL}$ provides a means for a CLS-FE in one network domain (e.g., a mobile device) to determine the presence of another network endpoint in its local vicinity (e.g., a home set top box or an office WLAN-based VoIP system). This link might be implemented by a DLNA/UPnP interface across a WLAN or Bluetooth. The two endpoints may be serviced by the same network provider or by different network providers. The + +reference point allows for the transfer of appropriate information to enable the two clients to notify their respective CC-FE of the other client's presence. + +#### **ES-FE to edge device reference point** + +The ES-FE interfaces with the edge device in which the ES-FE-enabled device is resident. Most commonly, it corresponds to an edge device API defined by the edge device vendor. The purpose of the reference point is to allow the ES-FE to interact with the underlying device. + +In addition, the ES-FE may be given access to APIs that enable "out of box" experiences, allowing the ES-FE to monitor and report on changes to the "local environment" such as the entry or exit of a mobile device (laptop, handset, etc.). This API would be similar in structure and content to UPnP defined for discovery and communications between LAN resident functions. + +#### **6.3.2 Actions** + +The majority of ES-FE actions originate when a ES-FE experiences environment changes, such as detection of new CSF functions within its local environment (nominally wireless access is assumed). + +ES-FE primarily reports on changes in the information it stores, for example it will: + +- Establish communications with CLS-FEs in the local environment (interface restricted to short range RF) to determine their identity, capability and security authorizations. +- Initial report on entities and/or services available in the local environment or changes in the devices or capabilities in the local environment. +- It is likely that ES-FE will be required to somehow report on alternate paths to the entities in the local environment (or to itself in cases where one end user device can connect to more than one access network, such as cellular and WLAN). + +#### **6.3.3 Information** + +ES-FE stores information regarding: + +- The local environment in terms of what networks and/or devices it can correspond with and the services available from them. +- The client's current location expressed as both a network address and (optionally) a physical location (the latter as an aid in emergency services dispatch, although this may be retrieved from the business management system (BSS) instead). +- The devices that are "resident" within the environment (loss of communications usually means that the devices have been moved out of range, powered off or failed). +- The devices that are transient within the environment (loss of communications indicates mobility, a normal event with respect to these devices). +- The current active session of the edge device. + +## **6.4 Client support functional entity (CLS-FE)** + +The CLS-FE provides session and resource information about the client and the user to the CC-FE. + +CLS-FE represents CSF within an end user device. Its role is twofold: + +- End user interaction – prompts end users for information and collects their response (if necessary, the users will be prompted for additional information if their original preferences were not absolutely clear). +- End user device interactions – allows for the push or pull of information to and from the end user device (e.g., the cellphone). For example, CLS-FE might update the user's handset-based address book if one of their contacts adds a new contact mechanism to their global set. + +CLS-FE generates $I_{C-CL}$ messages when there are changes of specific information (e.g., the end user places the device in a docking cradle, which may imply absence of the end user from the device's immediate vicinity and may cause CC-FE to change services for the user under user profile control). + +CLS-FE receives messages mainly relating to stored information on the device. The address book is the most obvious example. Calendar items being offered, accepted, updated are other examples. CLS-FE messaging from CC-FE would also be appropriate to advise the end user device that the device is in a "no ring zone" (a theatre) and that it must "vibrate" to "ring" instead of play some wonderfully confusing ring tone. + +### **6.4.1 Reference points** + +The CLS-FE supports the following CSF reference points: + +- $I_{C-CL}$ (see clause 6.1.1). + +$I_{C-CL}$ is the CLS-FE to CC-FE communications link. This link is used to update CC-FE's knowledge of the local client environment, to change information on the end user device or to interact with the user to resolve decision ambiguities in services automation. + +- $I_{CL-CL}$ + +$I_{CL-CL}$ is a CLS-FE to CLS-FE or ES-FE reference point. $I_{CL-CL}$ provides a means for a CLS-FE in one network domain (e.g., a mobile phone) to determine the presence of another network endpoint in its local vicinity (e.g., a home set top box or an office WLAN-based VoIP system). + +#### **CLS-FE to host reference point** + +Client to host reference points take many forms. The simplest to conceive is an API between the normal local application and the local operating system style. For example, APIs provided to access operating system managed resources. More specialized host interfaces are present in devices with specialized functions, such as mobile phones, or applications resident on the host device, such as an API to a calendar or address book application/service. + +### **6.4.2 Actions** + +The majority of CLS-FE actions originate when CLS-FE is hosted on a mobile device, which can therefore experience environment changes. Most fixed-location devices are assumed to implement ES-FE rather than CLS-FE. + +CLS-FE primarily reports on changes in the information it stores, for example it will: + +- Provide information resident on the device to CC-FE on demand or in response to a locally generated trigger (e.g., a change to the local address book on a cellphone). +- Notify CC-FE when its current location matches a "well known location". This may be determined by use of GPS or by recognizing the SSID of a local RF signal or some combination of attributes. +- Establish communications with CLS-FEs or ES-FEs in the local environment (interface restricted to short range RF) to determine their identity, capability and degree of cooperativeness. +- Initial report on entities and/or services available in the local environment or changes in the devices or capabilities in the local environment. +- It is likely that CLS-FE will be required to somehow report on alternate paths to the entities in the local environment (or to itself in cases where one end user device can connect to more than one access network such as cellular and WLAN). + +#### 6.4.3 Information + +CLS-FE stores information regarding: + +- The local environment in terms of what networks it can correspond with and the services available from them. +- The client's current location (as an aid to recognizing the clients "well known locations"). +- The client's well known locations. +- The current active session of the client. +- The client's information resident on the local device, or changes to stored information. + +## 6.5 Convergence policy functional entity (CP-FE) + +The CP-FE provides policy management and enforcement information to the CC-FE. It acts as a policy decision point within the CSF and then acts as a policy enforcement point in executing the policy guidance received. + +The CP-FE may update policy guidance to the CC-FE at any time. + +The CP-FE does not directly communicate with any CSF functions below CC-FE (e.g., CLS-FE, ES-FE or NS-FE). The network elements that NS-FE interacts with access the policy services through non-CSF-related channels. + +The CP-FE is capable of managing one or more than one CC-FE. + +Figure 6-2 provides a high-level view of the policy mechanism. + +![Figure 6-2: CSF policy mechanism diagram. The diagram shows a 'Convergence policy FE' block at the top, which contains two sub-blocks: 'Policy' and 'Policy management'. Below this block is a 'CC-FE' block. A vertical line connects the two blocks, labeled 'I_{C-P}'.](29f586959675cafdf81cf934954908eb_img.jpg) + +``` +graph TD; subgraph CP_FE [Convergence policy FE]; direction LR; P[Policy]; PM[Policy management]; end; CC_FE[CC-FE]; CP_FE --- ICP["I_{C-P}"]; style CP_FE fill:#ffff00,stroke:#333,stroke-width:1px; style CC_FE fill:#ffff00,stroke:#333,stroke-width:1px; style P fill:#add8e6,stroke:#333,stroke-width:1px; style PM fill:#add8e6,stroke:#333,stroke-width:1px; +``` + +Y.2013(06)\_F6-2 + +Figure 6-2: CSF policy mechanism diagram. The diagram shows a 'Convergence policy FE' block at the top, which contains two sub-blocks: 'Policy' and 'Policy management'. Below this block is a 'CC-FE' block. A vertical line connects the two blocks, labeled 'I\_{C-P}'. + +**Figure 6-2 – CSF policy mechanism** + +### 6.5.1 Reference points + +The CP-FE supports the following CSF reference point: + +- $I_{C-P}$ (see clause 6.1.1) + +The $I_{C-P}$ reference point is responsible for interaction between CP-FE and CC-FE. CC-FE uses this reference point to receive policies from CP-FE and to return a result to it. + +The $I_{C-P}$ reference point can be viewed as being similar to the "Go" interface defined within IMS [ITU-T Y.2021] for policy distribution. + +### 6.5.2 Actions + +CP-FE's actions are all driven by policy distribution needs. Thus CP-FE will provide policy guidance to the CC-FE on CC-FE start-up or when the policy stored within CP-FE is changed by the network operator. + +### 6.5.3 Information + +As a minimum IMS policy decision functionality to the CP-FE would be expected to provide information for the connected access networks. Additional information may be required to support CSF specifically, but this is for further study. + +# 7 Context of CSF within NGN + +## 7.1 Relationship to NGN functional architecture + +### 7.1.1 Introduction + +The converged service framework can be considered as an 'overlay' approach, amenable to interworking with existing end-to-end solutions, whether they are legacy ones (cellular, packet cable, etc.) or NGN (including IMS-based ones). See Appendix V for examples of CSF configuration models. + +The objective of this clause is to look more closely at the case where CSF operates in conjunction with NGN to better understand the positioning of the CSF functional architecture described in clause 6 within the NGN functional architecture as described in [ITU-T Y.2012]. + +Figure 7-1 shows the NGN architectural overview [ITU-T Y.2012]. The CSF relationships to existing standards such as OSA/Parlay, OMA open service environment (OSE) and underlying networks (e.g., IMS-style networks, wireline-style networks) are briefly covered in Appendix II. + +![Figure 7-1: The NGN architecture overview. This diagram illustrates the functional architecture of a Next-Generation Network (NGN). At the top, 'Applications' connect to the 'Service stratum' via the 'ANI' (Application Network Interface). The 'Service stratum' (green background) contains 'Applications support functions and service support functions' and 'Service control functions' (which include 'Service user profiles'). Below this is the 'Transport stratum' (yellow background), containing 'Transport control functions' (with 'Network attachment control functions' and 'Resource and admission control functions', including 'Transport user profiles') and 'Transport functions'. To the left, 'Management functions' (purple bar) connect to 'End-user functions' via the 'UNI' (User Network Interface). To the right, 'Other networks' connect via the 'NNI' (Network Network Interface). Dotted lines represent control planes, hatched lines represent media planes, and dashed green lines represent management planes. A legend at the bottom clarifies these line types.](51db757d054ce1ce83c436a3578b56ca_img.jpg) + +Y.2013(06)\_F7-1 + +..... Control +Media +Management + +Figure 7-1: The NGN architecture overview. This diagram illustrates the functional architecture of a Next-Generation Network (NGN). At the top, 'Applications' connect to the 'Service stratum' via the 'ANI' (Application Network Interface). The 'Service stratum' (green background) contains 'Applications support functions and service support functions' and 'Service control functions' (which include 'Service user profiles'). Below this is the 'Transport stratum' (yellow background), containing 'Transport control functions' (with 'Network attachment control functions' and 'Resource and admission control functions', including 'Transport user profiles') and 'Transport functions'. To the left, 'Management functions' (purple bar) connect to 'End-user functions' via the 'UNI' (User Network Interface). To the right, 'Other networks' connect via the 'NNI' (Network Network Interface). Dotted lines represent control planes, hatched lines represent media planes, and dashed green lines represent management planes. A legend at the bottom clarifies these line types. + +**Figure 7-1 – The NGN architecture overview** + +When operating in conjunction with NGN, the CSF functional entities are largely located in the NGN service stratum with some support functional entities reaching into the transport stratum and end-user functions in certain cases. + +### 7.1.2 CSF and the NGN functional architecture + +As described in clause 6, the CSF is made up of one or more convergence coordination functional entities (CC-FE), as well as supporting functional entities in the network support functional entity (NS-FE), edge support functional entity (ES-FE), the end devices for client support functional entity (CLS-FE) and policy management and enforcement support functional entity (CP-FE). Figure 7-2 illustrates the corresponding positioning of the CSF FEs in the context of the NGN generalized functional architecture. + +![Figure 7-2: The CSF relationship to the NGN functional architecture. The diagram shows the CSF functional entities (CP-FE, CC-FE, ES-FE, NS-FE, CLS-FE) and their relationships with NGN functional entities across three strata: Application support functions, Service control functions, and Transport control functions. A yellow box on the left represents 'End-user functions'. Dashed blue lines indicate CSF FE-NGN FE functional relationships, thick grey lines indicate intra-CSF reference points, and solid lines indicate intra-NGN FE reference points.](8fa679f79a1bb1f527cba9f29e784e89_img.jpg) + +The diagram illustrates the CSF relationship to the NGN functional architecture across three strata: + +- Application support functions and service support functions:** Includes Applications, ANI, CP-FE, CC-FE, ES-FE, NS-FE, and Converged services/applications (A-1: AS-FE, A-2: APL-GW-FE, A-3: APL-SCM-FE, A-4: SS-FE). +- Service control functions:** Includes S-1: S-CSC-FE, S-4: SL-FE, S-5: SUP-FE, S-6: SAA-FE, S-15: GSC-FE, and others. +- Transport control functions:** Includes T-12: T. user profile FE, T-11: TAA-FE, and others. + +End-user functions (yellow box) include CC-FE, ES-FE, and CLS-FE. + +Legend: + +- Dashed blue line: CSF FE-NGN FE functional relationship +- Thick grey line: Intra-CSF reference point +- Solid line: Intra-NGN FE reference point (not all shown here) + +Y.2013(06)\_F7-2 + +Figure 7-2: The CSF relationship to the NGN functional architecture. The diagram shows the CSF functional entities (CP-FE, CC-FE, ES-FE, NS-FE, CLS-FE) and their relationships with NGN functional entities across three strata: Application support functions, Service control functions, and Transport control functions. A yellow box on the left represents 'End-user functions'. Dashed blue lines indicate CSF FE-NGN FE functional relationships, thick grey lines indicate intra-CSF reference points, and solid lines indicate intra-NGN FE reference points. + +**Figure 7-2 – The CSF relationship to the NGN functional architecture** + +Figure 7-2 identifies three types of reference points. The thick grey line represents the reference points between CSF FEs (intra-CSF) (see clause 6 for further details). The dotted line shows reference points (or functional relationships) between CSF and NGN functional architecture FEs. The solid lines are reference points between NGN functional architecture FEs, which are not all shown here (see [ITU-T Y.2012] for further information). + +It should be noted that the CC-FE may be collocated with a CSF support functional entity, such as the NS-FE, ES-FE or CLS-FE. It should further be noted that other than the CC-FE and CP-FE, not all FEs need be present for operation. For example, the CSF may be implemented entirely in an operator's infrastructure through the use of CC-FEs, CP-FEs and NS-FEs, and without ES-FEs or CLS-FEs. + +In certain configurations, a CC-FE can be located in the end-user functions. In such a configuration the CC-FE coordinates the services in the local end-user environment and interacts with the peer CC-FE in the service stratum when service coordination is needed across network domains. + +#### **7.1.2.1 CSF and the application support functions and service support functions** + +The CC-FE resides within the application support and service support functions of the NGN architecture. + +The CC-FE should support coordination control for multiple invocations of services in single or multiple service component(s) within the NGN service stratum (see Figure 7-3, clause 7.2). + +The CC-FE interacts with the following functional entities within the application support and service support functions (see Figure 7-2): + +- A-1 – Application support FE (AS-FE): An AS-FE is a functional entity that provides the intelligence for a user-level service. An AS-FE communicates with a CC-FE in a manner similar to how an application communicates with an application gateway functional entity (APL-GW-FE). An AS-FE contacts a CC-FE when enacting a service on behalf of a user to determine the user capability and state across (and independently of) the multiple access networks or devices available to the user. +- A-2 – Application gateway FE (APL-GW-FE): The APL-GW-FE is an intermediary between the applications and functional entities in the service control function. The APL-GW-FE is analogous in some respects to the CC-FE. In particular, it may sit logically between an application and an S-CSC-FE or MRC-FE and communicate to applications over ANI. The CC-FE interacts with the APL-GW-FE in its communications with the "third party" applications for obtaining input from service provider databases. +- A-3 – Application service coordination manager FE (APL-SCM-FE): The APL-SCM-FE manages service interactions between multiple application services in NGN. By doing so, it might provide convergent services in NGN. But APL-SCM-FE is limited to the capabilities provided with the service control function, and the CC-FE has more global coordination capabilities across multiple domains. The CC-FE may interact with APL-SCM-FE to obtain service coordination information in its communication with application services in NGN. +- A-4 – Service switching FE (SS-FE): The SS-FE provides access and interworking to a legacy intelligent network (IN) service control point (SCP). The CC-FE may interwork with SS-FE to obtain service trigger information in its communication with legacy IN services. + +The CC-FE also interacts with the service control functions in the service stratum via the network support functional entity (NS-FE). In addition, the CC-FE interacts with the transport stratum via the edge support functional entity (ES-FE) and it also interacts with components within the end-user functions. + +The convergence policy functional entity (CP-FE) also resides within the application support and service support functions of the NGN architecture. + +NOTE – Interactions between CP-FE and additional FEs within the service stratum are for further study. + +#### **7.1.2.2 CSF and the service control functions** + +The NS-FE resides within the application support and service support functions of the NGN architecture. The NS-FE should support media service control for multiple invocations of media resources in single or multiple service component(s) within the NGN service stratum (see Figure 7-3). + +The NS-FE interacts with the functional entities located within the service control functions of the NGN architecture (see Figure 7-2): + +- S-1 – Serving call session control FE (S-CSC-FE): The S-CSC-FE is responsible for enabling access of end devices to application servers. The S-CSC-FE should include NS-FE behaviour to push information/respond to requests for information to a CC-FE. In particular, the S-CSC-FE/NS-FE should provide the following categories of information to a trusted CC-FE: + - Notification of triggers related to previously specified users or devices. + - Parameters related to sessions that are in progress. + - Notification of user/device registration status. + - Addressing, location information for devices known to be associated with a specified user. +- S-5 – Service user profile FE (SUP-FE): The SUP-FE is a database function that maintains user profile, device profile, presence, subscription and location information for an administrative domain. The SUP-FE should include NS-FE behaviour responsive to a CC-FE, providing access to its content according to its own rules of access privileges/trust. The NS-FE should filter its data prior to transmission to the CC-FE according to these rules. Conditioned upon establishment of trust, the NS-FE should also accept and store SUP-FE-related information from a CC-FE as a proxy for a user or user device. +- S-6 – Service authentication and authorization FE (SAA-FE): The SAA-FE provides authentication and authorization in the service stratum. +- S-15 – General services control FE (GSC-FE): The general services control functional entity (GSC-FE) acts as a contact point for application support and service support functional entities, as well as end-user functions. The GSC-FE maintains session-related state as needed to assist in policy actions. It should include NS-FE behaviour accordingly. + +It is expected that a CSF component may need to establish its identity and authority to access or provide information when communicating with an administrative domain operated by a different service/network provider. + +NOTE – Interactions between NS-FE and additional FEs within the service control functions are also envisioned and are for further study. + +#### **7.1.2.3 CSF and the transport control functions** + +The ES-FE resides within the application support and service support functions of the NGN architecture and interacts with the following functional entities located within the transport stratum: + +- T-12 – Transport user profile FE (TUP-FE): The TUP-FE is responsible for storing user profiles related to the transport stratum. The TUP-FE includes NS-FE behaviour responsive to a CC-FE, providing access to its content according to its own rules of access privileges/trust. The NS-FE should filter its data prior to transmission to the CC-FE according to these rules. Conditioned upon establishment of trust, the ES-FE should also accept and store TUP-FE-related information from a CC-FE as a proxy for a user or user device. +- T-11 – Transport authentication and authorization FE (TAA-FE): TAA-FE provides authentication and authorization functions in the transport stratum. It is expected that a CSF component may need to establish its identity and authority to access or provide information when communicating with an administrative domain operated by a different service/network provider. + +NOTE – Interactions between ES-FE and additional FEs within the transport control functions are also envisioned and are for further study. + +#### 7.1.2.4 CSF and the end-user functions + +The client support functional entity (CLS-FE) resides in the end-user functions as shown in Figure 7-2. The CLS-FE interacts with components of the end-user functions of the NGN architecture. The CLS-FE should support priority-based service execution when multiple services are invoked in parallel, and support multiple interfaces with multiple services in single or multiple service component(s). See Figure 7-3. + +The CC-FE and ES-FE may be used in the end-user functions (see Figure 7-2). + +## 7.2 Service convergence types + +Service convergence can be described as a set of services presented to the user by interworking or integrating component services, in single or multiple service component(s) of the NGN functional architecture [ITU-T Y.2012], to various types of terminals attached to various types of access networks, each with its own restrictions and capabilities. + +In the context of CSF, service convergence can be described in several ways. Within this Recommendation, a classification based on the functional architecture point of view has been chosen leading to the following architectural types: + +- Type 1: Converged service in a single service component (e.g., IP multimedia service component). +- Type 2: Converged service over multiple service components (e.g., IP multimedia service component + PSTN/ISDN emulation service component). +- Type 3: Converged service over multiple service components and other networks (e.g., IP multimedia service component + Internet service). + +Figure 7-3 shows the three different types considered in this Recommendation for realizing converged services. + +![Figure 7-3: Converged services types. This diagram illustrates the architecture of converged services, divided into two main strata: the Service stratum (top) and the Transport stratum (bottom). The Service stratum includes Applications, Application support functions and service support functions, S. user profile functions, Other NGN service components, Service control functions, PSTN/ISDN emulation service component, and IP multimedia service component. The Transport stratum includes T. user profile functions, Network attachment control functions (NAFC), Resource and admission control functions (RAFC), Access network functions, Edge functions, and Core transport functions. On the left, Legacy terminals, Customer networks, and NGN terminals connect to End-user functions via Gateways (GW). On the right, Other networks are shown. Three types of convergence are highlighted: Type 1 (Converged services in a single component), Type 2 (Converged services over multiple components), and Type 3 (Converged services with other network). A note at the bottom states: 'NOTE – Gateway (GW) may exist in either transport stratum or end-user functions.' The reference Y.2013(06)_F7-3 is also present.](c914f51f4427bc672dd0526cfc90ebe9_img.jpg) + +NOTE – Gateway (GW) may exist in either transport stratum or end-user functions. + +Y.2013(06)\_F7-3 + +Figure 7-3: Converged services types. This diagram illustrates the architecture of converged services, divided into two main strata: the Service stratum (top) and the Transport stratum (bottom). The Service stratum includes Applications, Application support functions and service support functions, S. user profile functions, Other NGN service components, Service control functions, PSTN/ISDN emulation service component, and IP multimedia service component. The Transport stratum includes T. user profile functions, Network attachment control functions (NAFC), Resource and admission control functions (RAFC), Access network functions, Edge functions, and Core transport functions. On the left, Legacy terminals, Customer networks, and NGN terminals connect to End-user functions via Gateways (GW). On the right, Other networks are shown. Three types of convergence are highlighted: Type 1 (Converged services in a single component), Type 2 (Converged services over multiple components), and Type 3 (Converged services with other network). A note at the bottom states: 'NOTE – Gateway (GW) may exist in either transport stratum or end-user functions.' The reference Y.2013(06)\_F7-3 is also present. + +**Figure 7-3 – Converged services types** + +In order to illustrate the different types shown in Figure 7-3, scenario examples for type 1, type 2 and type 3 are described in clauses III.1, III.2 and III.3, respectively. + +# Appendix I + +## CSF use cases + +(This appendix does not form an integral part of this Recommendation) + +This appendix includes example use cases to highlight the functionality of the CSF. + +### I.1 Voice and presence service converged service + +This use case describes the role that CC-FE plays in tracking user state (and location), recognizing the services that need to be executed when a user state changes and distributing that information when appropriate. It takes a core-network-centric implementation of CSF. It handles brokering of two services: presence (SIP-based service) and voice telephony (non-SIP-based service). + +The dotted lines in Figure I.1 are CSF-internal flows. + +Assumptions: + +- 1) This flow only captures the interactions with the CSF system. The other interactions are only there for completeness of the use case. +- 2) The call flows shown are high level and not meant to show the actual protocol exchanges. +- 3) The NS-FE/legacy CN shown is merged together to simplify the use case scenario. The NS-FE keeps the state change information about the user and informs the CC-FE about it. Not all flows shown involve NS-FE but they do always involve some entities in the core network (CN). + +![Sequence diagram for Voice and presence service converged service use case.](9167fa5ebcb66516d1bbb421ec9bba7b_img.jpg) + +The diagram is a sequence diagram showing the interactions between six entities: Legacy user device, Caller, NS-FE/legacy CN, CC-FE, Presence service, and Buddies. The interactions are as follows: + +- 1) Register service: Solid arrow from CC-FE to Presence service. +- 2) Register: Solid arrow from Caller to NS-FE/legacy CN. +- 2a) Register presence: Solid arrow from NS-FE/legacy CN to Presence service. +- 3) Acknowledge: Solid arrow from Presence service to CC-FE. +- 3a) Acknowledge: Solid arrow from CC-FE to Legacy user device. +- 4) User preferences: Dotted arrow from NS-FE/legacy CN to CC-FE. +- 5) User available: Solid arrow from CC-FE to Presence service. +- 6) User available: Solid arrow from Presence service to Buddies. +- 7) Call offer: Solid arrow from Caller to NS-FE/legacy CN. +- 8) Call offer: Dotted arrow from NS-FE/legacy CN to CC-FE. +- 9) Trigger other services?: Dotted arrow from CC-FE to Presence service, looping back to CC-FE. +- 10) Call setup: Dotted arrow from CC-FE to NS-FE/legacy CN. +- 11) Call setup: Solid arrow from NS-FE/legacy CN to Legacy user device. +- 12) Call accept: Dotted arrow from NS-FE/legacy CN to CC-FE. +- 13) Trigger other services?: Dotted arrow from CC-FE to Presence service, looping back to CC-FE. +- 14) User is busy: Solid arrow from CC-FE to Presence service. +- 15) User busy: Solid arrow from Presence service to Buddies. + +Sequence diagram for Voice and presence service converged service use case. + +NOTE – Dotted arrows above are non-CSF messages. Solid arrows are CSF messages. + +Y.2013(06)\_FI.1 + +Figure I.1 – Voice and presence service converged service use case + +Call flow description: + +- 1) The presence service registers with CC-FE. +- 2) User device registers with the service provider. +- 3) Service provider network acknowledges the registration. +- 4) The NS-FE notifies CC-FE of user registration. +- 5) CC-FE notifies the presence service that the user device is registered and available for instant messaging. +- 6) Presence service notifies the users on the buddies list that the user is available. +- 7) A call is offered to the legacy CN for the user. +- 8) NS-FE relays the request to the CC-FE for the user. +- 9) The CC-FE determines that there are no terminating triggers registered for the device and that the user is available to take the call. +- 10) CC-FE informs the NS-FE in the CN to proceed with call setup. +- 11) Call setup takes place. +- 12) NS-FE notifies CC-FE that the call is accepted. +- 13) CC-FE reviews the users "subscribed services", identifies presence as a subscribed service, requiring a "presence" update when the user changes state and user preference for "do not disturb while on a call". +- 14) CC-FE forwards the user's "busy" state to the presence service. +- 15) The presence service forwards "not available" to the user's "buddies". + +NOTE – The presence service retrieving the users buddy list from the HSS through the NS-FE is not shown in this example. + +### **I.2 Call forwarding – Video conferencing converged service** + +This use case shows a service which coordinates a call forwarding service and a video conferencing service. When the user starts the video conferencing service, her/his terminal state changes to busy which causes the network to change its behaviour in reaction to future calls. At this time, if there are other incoming calls, they need to be automatically forwarded to an alternate terminal, and Figure I.2 shows the case. + +The dotted lines in Figure I.2 are CSF-internal flows. + +Assumptions: + +- 1) This flow captures the interactions with the CSF system. The other interactions are only there for completeness of the use case. +- 2) The call flows shown are high level and not meant to show the actual protocol exchanges. +- 3) The NS-FE/CN shown is merged together to simplify the use case scenario. The NS-FE keeps the state change information about the user and informs the CC-FE about it. Not all flows shown involve NS-FE but they do always involve some entities in the core network. + +![Sequence diagram for Call forwarding: Video conferencing converged service use case. The diagram shows interactions between User, User device, CC-FE, Video conf service, Call fwd service, NS-FE/CN, and Alternative destination. The flow includes registration steps, user profile retrieval, video call initiation, media service setup, call placement and acceptance, and call forwarding logic based on user preferences.](cbdfdade780e677eb1c1aef3081ce9ef_img.jpg) + +``` + +sequenceDiagram + participant User + participant User device + participant CC-FE + participant Video conf service + participant Call fwd service + participant NS-FE/CN + participant Alternative destination + participant Video destination + participant Alternative caller + + CC-FE->>Video conf service: 1) Register + Video conf service->>CC-FE: 2) Register + User device->>NS-FE/CN: 3) Register + NS-FE/CN->>CC-FE: 4) Register acknowledge + NS-FE/CN-->>CC-FE: 5) User profile + User->>User device: 6) Select video call destination + User device->>Video conf service: 7) Make video call + Video conf service->>CC-FE: Info exchange + Video conf service->>Video conf service: 8) Setup media services + Video conf service->>Video destination: 9) Place video call + Video destination->>Video conf service: 10) Accept video call + Video conf service->>CC-FE: Info exchange + User device->>User: 11) Enjoy video call + NS-FE/CN->>CC-FE: 12) Call offered + CC-FE-->>CC-FE: 13) User preference? + CC-FE->>Call fwd service: 14) Forward call + +``` + +Y.2013(06)\_F1.2 + +Sequence diagram for Call forwarding: Video conferencing converged service use case. The diagram shows interactions between User, User device, CC-FE, Video conf service, Call fwd service, NS-FE/CN, and Alternative destination. The flow includes registration steps, user profile retrieval, video call initiation, media service setup, call placement and acceptance, and call forwarding logic based on user preferences. + +**Figure I.2 – Call forwarding: Video conferencing converged service use case** + +Call flow description: + +- 1) Register the video conferencing service with CC-FE. +- 2) Register call forwarding service with CC-FE. +- 3) The user device registers with the HSS through the NS-FE. +- 4) The HSS acknowledges the registration through the NS-FE. +- 5) The HSS sends CC-FE user profile information through the NS-FE. +- 6) The user initiates a video conference by selecting a group. +- 7) User device requests a video conference. +- 8) The video conference call service initiates the requisite media bridge services (reported to CC-FE). +- 9) Video conference service initiates legs of the conference call to each of the call recipients based on user and device state information provided by the CC-FE. +- 10) Recipients accept calls (reported to CC-FE). +- 11) Users enjoy their video conference. +- 12) The CC-FE is notified of another call addressed to the user through the NS-FE. +- 13) The CC-FE determines the user is busy and has a preference to forward calls while busy to an alternate device (may be voice mail, may be another user device). +- 14) CC-FE has call forwarding initiate a call to the destination designated in the user's profile. + +NOTE – HSS is omitted due to space limitations. + +### I.3 Movement of conference call from a fixed client to mobile client + +To provide service continuity across administrative domains it is necessary to provide a service coordination network entity (e.g., a CC-FE) that is aware of the user's state and can facilitate the + +join operation of a user's session across these administrative boundaries. Service elements in need of coordination are the user's available resources and device states on both sides of the two, or more, administrative domains. The service coordination network entity is responsive to service requests from either the fixed network or mobile network. + +Figure I.3 presents a use case scenario in which "A" is in a video conference call with "B." "A" decides to leave his/her location but wishes to continue the conversation on a mobile device without interruption. "A" is able to push a button on the mobile phone and have the audio portion of the call move to the mobile phone automatically. + +![Sequence diagram showing the movement of a conference call from a fixed client to a mobile client across three networks: Mobile network, Wireline network, and Enterprise.](a149b400127a3e3e50b3c98d27c5935c_img.jpg) + +``` + +sequenceDiagram + participant A_mobile as A's mobile CLS-FE + participant Come_to_me as Come-to-me application server + participant B as B + participant CC_FE as CC-FE + participant ES_FE as ES-FE + participant A_desk as A's desk phone + + A_mobile-->>Come_to_me: 2) Move call + Come_to_me-->>CC_FE: 3) Report A's active calls + CC_FE-->>Come_to_me: 4) A's active calls + ES_FE-->>CC_FE: 1) Report A's status + B-->>A_desk: Connected on video call + +``` + +The diagram illustrates the movement of a conference call across three administrative domains: Mobile network, Wireline network, and Enterprise. + - In the Mobile network, A's mobile CLS-FE sends a "2) Move call" message to the Come-to-me application server. + - In the Wireline network, the Come-to-me application server sends a "3) Report A's active calls" message to the CC-FE, which then responds with "4) A's active calls". + - In the Enterprise, the ES-FE sends a "1) Report A's status" message to the CC-FE. + - A thick solid arrow labeled "Connected on video call" spans from participant B in the Wireline network to A's desk phone in the Enterprise, indicating an ongoing call. + +Sequence diagram showing the movement of a conference call from a fixed client to a mobile client across three networks: Mobile network, Wireline network, and Enterprise. + +NOTE – Dotted arrows above are non-CSF messages. Solid arrows are CSF messages. + +**Figure I.3 – Movement of a conference call from a fixed client to a mobile client** + +NOTE – Dotted arrows above are non-CSF messages. Solid arrows are CSF messages. + +Call flow description: + +- 1) A's desk terminal is connected to B's phone on video call. An ES-FE in A's enterprise network notifies A's CC-FE about A's status. User A needs to walk out of office and continue with the voice part of the video call. +- 2) A's mobile device requests its "come to me" application to find its calls and move them to the mobile device. +- 3) The "come to me" application queries the CC-FE to gather the active calls associated with user A. +- 4) The CC-FE responds with the list of active calls compatible with A's devices, in this case a single video call between A's desk phone and B's phone. + +NOTE – The transfer of the voice call from A's desk phone to A's mobile device is done by the networks and does not involve CSF functional entities and hence it is not shown. + +### **I.4 Hybrid solution for a cross-network video + phone converged service (video on demand point of sale service using the CSF support and coordination functional entities)** + +The use case presented in this clause highlights some of the key features of the CSF with respect to media, mobility of content rights and transaction-based services. Additionally, it shows a flexible set of coordination models (third party, loosely-coupled operators). + +#### **I.4.1 VoD point of sale use case description** + +"User" is at hotel and has subscribed to high-speed wireless provided by "Operator 1". User also subscribes to a video service at home from "Operator 2" (also known as "MSO"). Operator 2 broadcasts its pay-per-view movie trailers over broadband wireless as a third party to Operator 1. User can buy these movies while watching the advertisement on the mobile device. The licence to view the movie can be obtained for viewing either: + +- i) only by the mobile device; +- ii) for some default point of display (such as through a home set top box); or +- iii) for multiple devices belonging to User (such as a laptop, a home HDTV, etc.). + +If User were to choose an option including rights to view on the mobile device (such as option i), then this capability could be arranged between Operators 1 and 2 via Operator 2's CC-FE. This use case assumes that User buys a licence such that the movie can be viewed in all of his devices. User then chooses to watch it while at the hotel. While watching the movie, User gets a call and chooses to answer it. The movie pauses automatically or via an interface in the mobile phone. It resumes when User is done with the call. + +#### **I.4.2 Assumptions** + +- 1) User's mobile device has an application (referred to as client app in the following discussion) which is used to view the advertisements and order movies. It may be in the form of a web browser using a video viewer as a plug-in, and widgets for user directives (such as "buy movie") and preferences (such as "always buy a copy for my laptop"). +- 2) There is a CLS-FE in User's laptop. The CLS-FE supports the interfaces and procedures that enable the CC-FE to access information about the point of display (POD), i.e., device capabilities such as display capability, availability of high-speed interface, etc. +- 3) There is a CC-FE that can identify and interact with all the CLS-FEs corresponding to User. Specifically the laptop in this case. +- 4) There is an application server (termed "VoD AS"), presumably provided by Operator 2, that has the information about the movies and can also identify and interact with the CC-FE. + +#### **I.4.3 Instantiation using a single CC-FE** + +The sequence of messages in Figures I.4.1 and I.4.2 provide an overview of one instantiation of the use case in the context of CSF. + +Steps 1, 2 and 3 are application-specific and do not bear on the CSF description. As such, they are not described in detail. + +Dotted arrows in Figures I.4.1 and I.4.2 are non-CSF messages. Solid arrows are CSF messages. + +![Sequence diagram for CSF use case: Video on demand point of sale. The diagram shows interactions between a Mobile device (Client App) and a Laptop (NS-FE, CC-FE, VoD AS, VoD content, CLS-FE, Client app). The process starts with a query for movies, followed by advertisement, purchase request, and capability discovery. Capability requests are sent to NS-FE and CLS-FE, with responses returning to CC-FE. A push licence is then sent to the Mobile device. A note indicates 'If not cached' for the push licence step. The process ends with a push licence to the Laptop Client app.](69b7bd65e85cdef6fdd7fb0a8194257c_img.jpg) + +``` + +sequenceDiagram + participant MD as Mobile device + participant NSFE as NS-FE + participant CCFE as CC-FE + participant VoDAS as VoD AS + participant VoDContent as VoD content + participant CLSFE as CLS-FE + participant LaptopClient as Laptop Client app + + MD->>VoDAS: 1) Query for movie(s) + VoDAS->>MD: 2) Advertisement for movie(s) + MD->>VoDAS: 3) Purchase request (movie ID) + VoDAS->>CCFE: 4) Capability discovery + CCFE->>NSFE: 5a) Capability request + CCFE->>CLSFE: 5b) Capability request + NSFE-->>CCFE: 6a) Capability response + CLSFE-->>CCFE: 6b) Capability response + CCFE->>VoDAS: 7) Capability response + VoDAS->>VoDContent: 8) DRM determination + VoDContent->>CCFE: 9) Push licence + CCFE->>MD: 10a) Push [licence 1] + MD->>LaptopClient: 10b) Push [licence 1] + CCFE->>LaptopClient: 10c) Push [licence 2] + +``` + +Y.2013(06)\_Fl.4-1 + +Sequence diagram for CSF use case: Video on demand point of sale. The diagram shows interactions between a Mobile device (Client App) and a Laptop (NS-FE, CC-FE, VoD AS, VoD content, CLS-FE, Client app). The process starts with a query for movies, followed by advertisement, purchase request, and capability discovery. Capability requests are sent to NS-FE and CLS-FE, with responses returning to CC-FE. A push licence is then sent to the Mobile device. A note indicates 'If not cached' for the push licence step. The process ends with a push licence to the Laptop Client app. + +**Figure I.4.1 – CSF use case: Video on demand point of sale** + +![Sequence diagram for CSF use case: VoD with call session control. The diagram shows interactions between a Mobile device (Client app) and a Laptop (NS-FE, CC-FE, VoD AS, VoD content, CLS-FE, Client App). The process starts with a view of a movie, followed by resource state, invite, call begin, get state (user), state (movie t=12), pause (t=12), and display (continue?). The process ends with a response (yes), continue (t=12), and a movie view.](dcb5711d118ae6753b0e12f86eda37db_img.jpg) + +``` + +sequenceDiagram + participant MD as Mobile device + participant NSFE as NS-FE + participant CCFE as CC-FE + participant VoDAS as VoD AS + participant VoDContent as VoD content + participant CLSFE as CLS-FE + participant LaptopClient as Laptop Client App + + MD->>VoDContent: 11) view + VoDContent-->>LaptopClient: Movie + VoDContent-->>CCFE: 12) Resource state + MD->>NSFE: 13) Invite + NSFE->>CCFE: 14) Call begin + CCFE->>CLSFE: 15) Get state (user) + CLSFE-->>CCFE: 16) State (movie t = 12) + CCFE->>VoDAS: 17) Pause (t = 12) + VoDAS->>VoDContent: 18) Pause (t = 12) + VoDContent-->>LaptopClient: 19) Pause + MD->>NSFE: 20) Bye + NSFE-->>CCFE: 21) Call end + CCFE->>CLSFE: 22) Display (continue?) + CLSFE-->>CCFE: 23) Response (yes) + CCFE->>VoDAS: 24) Continue (t = 12) + VoDAS->>VoDContent: 25) Continue (t = 12) + VoDContent-->>LaptopClient: Movie + +``` + +Y.2013(06)\_Fl.4-2 + +Sequence diagram for CSF use case: VoD with call session control. The diagram shows interactions between a Mobile device (Client app) and a Laptop (NS-FE, CC-FE, VoD AS, VoD content, CLS-FE, Client App). The process starts with a view of a movie, followed by resource state, invite, call begin, get state (user), state (movie t=12), pause (t=12), and display (continue?). The process ends with a response (yes), continue (t=12), and a movie view. + +**Figure I.4.2 – CSF use case: VoD with call session control** + +#### **I.4.4 Call flow description** + +- 1) User sends a query from his/her mobile device to the multiple services operator (MSO) a.k.a. Operator 2, a VoD content provider, for the latest advertised movies. This query is received by the VoD application server (AS) owned by the MSO. +- 2) The VoD AS responds with the list of latest advertised movies to User. +- 3) User decides to order a selected movie from the advertised list of movies. The application in the mobile device informs the VoD AS of User's intention to buy the selected movie. + +At this point, to complete the transaction, the VoD AS needs to determine what devices are available to User, what formats can be used on each of User's devices, and the required digital rights to use the purchased content. In other words it needs to know the capabilities of the mobile device, as well as other user resources, such as a laptop to view the movie or a TV at home connected to a set top box (STB). + +- 4) The VoD AS queries the CC-FE to determine the display capabilities and preferences associated with User to view the movie. +- 5) In response to the query from the VoD AS, the CC-FE requests information about other user resources associated with the user ID (in this case the mobile device and laptop). + - a) CC-FE requests the mobile device's serving NS-FE to obtain point of display (POD), i.e., device capabilities such as display capability, availability of high-speed interface etc., of User's mobile device. + - b) CC-FE requests the laptop's CLS-FE to obtain POD, i.e., device capabilities such as display capability, availability of high-speed interface, etc., of User's laptop. +- 6) The support functions respond to the CC-FE's request: + - a) Mobile device's serving NS-FE returns to the CC-FE the requested mobile device's POD resource capability information. + - b) Laptop's CLS-FE returns to the CC-FE the requested User's laptop POD resource capability information. +- 7) The CC-FE provides the VoD AS with the requested information about each of User's associated devices that may be used to view the converged services managed movie. +- 8) VoD AS conducts the DRM determination for the user. +- 9) Based on the response from the CC-FE, the VoD AS constructs a licence appropriate for each individual user device. The VoD AS sends the CC-FE the resulting composite message containing all the appropriate licences; this is a required action due to the VoD AS not being a peer to all of User's devices. +- 10) The CC-FE sends the licences to the appropriate user devices. +- 11) The laptop viewer contacts the VoD content server to begin streaming the video. A VoD session is established between the content server and the laptop client application. +- 12) When the video session starts, the laptop CLS-FE detects this and pushes an unsolicited resource state response message to the CC-FE. +- 13) A phone call comes to User's mobile device, and User answers the call. +- 14) The NS-FE receives a trigger from the S-CSC-FE in cellular operator's IMS network, based on the mobile device's state change and sends a session response message to the CC-FE notifying the call state. +- 15) The CC-FE issues a get state resource request to User's laptop CLS-FE. +- 16) User's laptop CLS-FE responds with a time marker of when in the video stream the get state request was received and sends it to the CC-FE. + +- 17) After CC-FE receives the state info from CLS-FE, it sends a PAUSE command to the VoD AS to instruct it to PAUSE the streaming of the video. +- 18) The VoD AS informs the VoD content server of a request to PAUSE streaming of video. +- 19) The streaming of video is paused. +- 20) The call ends. +- 21) The NS-FE notifies the CC-FE that the call has ended. +- 22) The CC-FE determines the appropriate CLS-FE to contact and sends the display restart request information to User's VoD display. +- 23) The laptop CLS-FE sends its user-defined response to the CC-FE. +- 24) The response is then sent to the VoD AS. In this use case we assume that User wishes to continue the viewing of the movie from the point of the call. +- 25) The VoD AS then sends the appropriate signal to the VoD content server to continue streaming of the movie. + +NOTE – If pausing is based on user inputs, the CC-FE may add the information to the INVITE, i.e., the INVITE may have embedded information that would be given to the CLS-FE if User answers the call. The embedded information would be processed by CLS-FE in the client device and prompt User to "pause movie? Yes or no". This response would be sent by the CLS-FE to the CC-FE which in turn can talk to the VoD AS, if needed. + +### **1.5 Integrating information to improve customer service** + +#### **1.5.1 Assumptions** + +- 1) There are several enterprise domains involved: an airline, an airport WLAN operator, a cellular operator and a passenger's business. +- 2) The passenger's business holds his calendar which includes travel events. +- 3) The airline has several enterprise applications: + - a) The "passenger boarding status application" helps identify passengers who hold confirmed seats but who have not yet passed through the gate to the plane (correlated by electronically reading the boarding passes). + - b) The "passenger locator" application can resolve WLAN and cellphone registrations to determine if the devices are within the airport terminal. + - c) The "passenger data" application provides the airline's other applications with controlled access to passenger data, including methods of contact for notifications. +- 4) The airport operates a WLAN service that cooperates with each of the local cellular operators to provide high-speed access to cellular customers with dual mode phones while within the airport boarding areas. +- 5) The cellular operator provides: + - a) A "location service" that allows partner applications to request the latest position fix on a cellphone. + - b) A "travel manager" application that coordinates e-ticket transactions with the subscribers preferred airline(s) to expedite their travel needs. + - c) An "enterprise integration" application that allows enterprise applications to stimulate the cellular network to perform tasks. + +#### I.5.2 Step-by-step: Phase 1 – Getting a boarding pass while driving to the airport + +See Figure I.5.1. + +- 1) A passenger's time-based "business calendar" application contacts the cellular operator's CC-FE to notify the passenger's personal location-capable "travel manager" application (provided by the cellular operator) that the passenger needs a boarding pass for his flight. +- 2) The cellular operator's "travel manager" application confirms the user is on the airport ramp and contacts the airline to confirm travel and acquire a boarding pass. +- 3) The airline "boarding pass" application confirms the passenger's travel plans with the airline's "passenger data" application. +- 4) The airline "boarding pass" application contacts the cellular operator's "travel manager" application to authorize the user and forwards the boarding pass to the "travel manager" application. +- 5) The cellular operator's "travel manager" application forwards the electronic boarding pass to the user's cellphone for storage. + +![Sequence diagram illustrating the process of getting a boarding pass while driving to the airport.](e05b36c0d46549e681ce6581422c66b2_img.jpg) + +The diagram is a sequence diagram showing the interactions between several entities: Business enterprise (Business calendar), Handset CLS-FE, Cellular operator (CC-FE, Travel manager), Airport (WLAN), and Airlines (Boarding pass, Passenger data). The process follows these steps: + +- 1) Needs boarding pass: Business calendar to CC-FE. +- 1a) Needs boarding pass: CC-FE to Travel manager. +- 2) Get boarding pass: Travel manager to Boarding pass. +- 3) Scheduled flights: Boarding pass to Passenger data. +- 3a) Boarding pass: Passenger data to Boarding pass. +- 4) Boarding pass: Boarding pass to Travel manager. +- 5) Store boarding pass: Travel manager to CC-FE. +- 5a) Store boarding pass: CC-FE to Handset CLS-FE. + +Y.2013(06)\_FI.5-1 + +Sequence diagram illustrating the process of getting a boarding pass while driving to the airport. + +Figure I.5.1 – Getting a boarding pass + +#### I.5.3 Step-by-step: Phase 2 – Boarding the plane + +See Figure I.5.2. + +- 1) (Some time later) The airline's gate agent finishes boarding the passengers waiting in the gate area and requests a report on the status of boarded passengers, which indicates that one passenger with a boarding pass has not boarded the plane. To expedite departure the gate agent invokes the airline's "passenger locator" application. The "passenger locator" application asks the "passenger data" application for methods of contact to the passenger. +- 2) The "passenger data" indicates that the passenger carries a dual mode cellphone, and provides the requisite identity information. +- 3) The "passenger locator" application requests notification from the airports WLAN operator for registrations of the passenger's WLAN identity within the airport for the next 10 minutes. + +- 4) The WLAN registry responds that the passenger is not currently in the airport WLAN coverage. +- 5) The "passenger locator" application requests the passenger's location from the CC-FE indicated by contact information in the passenger's data. +- 6) The CC-FE responds with last known location of the passenger, i.e., the entrance of the airport terminal, at a time 20 minutes ago. Meanwhile, the passenger works his way through security at the airport. +- 7) Exiting security, the passenger's dual mode cellphone attempts to register with the airport's WLAN. +- 8) The airport's WLAN registry identifies the passenger's cellphone ID and immediately notifies the airlines "passenger locator" application that the passenger has registered with the AP beyond the security area. +- 9) The "passenger locator" application notifies the gate agent that the passenger has just cleared security. +- 10) The "passenger locator" application calls the gate agent and passenger (on his (now WLAN-registered) cellphone) simultaneously and the agent informs him of the gate number and that the plane is waiting on him for departure. +- 11) Once the passenger is in the gate area his cellphone forwards his electronic boarding pass to the ticket counter and the CLS-FE on the cellphone communicates the transaction to the CC-FE, clearing the user state for the boarding pass/locator. + +![Sequence diagram illustrating the boarding process involving Cellular operator, Airport, and Airlines.](c76da2d73c064464051d1583fd80bb6b_img.jpg) + +``` + +sequenceDiagram + participant CO as Cellular operator + participant A as Airport + participant AL as Airlines + + CO-->>A: 1a) User cleared + A-->>AL: 1) Missing passengers? + AL-->>A: 1a) One missing + AL-->>A: 1b) Find passenger + A-->>AL: 1c) Passenger contacts? + AL-->>A: 2) Passenger contacts + A-->>AL: 3) Passenger location - 10 mins + AL-->>A: 4) Received + A-->>AL: 5) Passenger location now + AL-->>A: 6) Last known passenger location + A-->>AL: 7) Register + AL-->>A: 8) User registered + A-->>AL: 9) Passenger found + AL-->>A: 10) Call passenger + AL-->>A: 10) Call gate agent + A-->>AL: 11) Send boarding pass + +``` + +The diagram is a sequence diagram showing the interactions between three main entities: Cellular operator, Airport, and Airlines. Each entity has a set of components represented by boxes at the top: Cellular operator (Handset CLS-FE, CC-FE), Airport (WLAN, Boarding pass), and Airlines (Passenger locator, Boarding status, Gate agent). The sequence of events is as follows: 1) Airlines' Boarding status asks Airport's Gate agent '1) Missing passengers?'. 1a) Gate agent responds '1a) One missing'. 1b) Boarding status asks Gate agent '1b) Find passenger'. 1c) Boarding status asks Airlines' Passenger locator '1c) Passenger contacts?'. 2) Passenger locator responds '2) Passenger contacts'. 3) Boarding status sends '3) Passenger location - 10 mins' to Boarding pass. 4) Boarding pass sends '4) Received' to Boarding status. 5) Boarding status sends '5) Passenger location now' to Boarding pass. 6) Boarding status sends '6) Last known passenger location' to Boarding pass. 7) Boarding pass sends '7) Register' to WLAN. 8) WLAN sends '8) User registered' to Boarding pass. 9) Boarding pass sends '9) Passenger found' to Boarding status. 10) Boarding status sends '10) Call passenger' to Handset CLS-FE and '10) Call gate agent' to Gate agent. 11) Handset CLS-FE sends '11) Send boarding pass' to CC-FE. 1a) CC-FE sends '1a) User cleared' to Handset CLS-FE. + +Sequence diagram illustrating the boarding process involving Cellular operator, Airport, and Airlines. + +Y.2013(06)\_FI.5-2 + +**Figure I.5.2 – Boarding the plane** + +# **Appendix II** + +## **Standards related to CSF** + +(This appendix does not form an integral part of this Recommendation) + +### **II.1 CSF relationship to OSA/Parlay** + +The CSF defines an architectural framework that provides a coherent view of information available at different network entities across dissimilar networks, with one benefit being easier creation of new services that provide a seamless user experience across multiple networks. A salient feature of the framework is that it accommodates and uses functions resident in the core network, edge devices and end user devices. The CSF framework is further concerned with enabling smooth and consistent operation of applications across disparate networks, be they NGN, legacy or other. + +While a Parlay/OSA gateway provides access to information available from one or more points in a given network, the CC-FE obtains the information from multiple networks, processes them and then provides the processed information to the applications in a manner that significantly reduces the complexity of interacting with these multiple and heterogeneous networks directly. + +While Parlay/OSA allows creation of applications that function in multiple networks, CSF allows the application to function smoothly and consistently when users, devices or sessions cross the boundaries of networks or administrative domains. + +### **II.2 CSF relationship to OMA and OSE** + +OSE (OMA service environment) describes the logical interactions to, from and among OMA enablers and describes a logical architecture for OMA enabler implementations. It is a conceptual environment that provides interfaces to applications (interfaces I0 or I0+P), interfaces to service providers' execution environments (I1) and the interfaces to invoke and use underlying network capabilities and resources for enabler implementations (I2). + +OSE focuses on service stratum, while CSF suggests functionality which exists in the core network, edge devices and terminals. OSE works on the convergence of widely deployed services and applications. It is network-resource-independent. OSE does not mention any part of the convergence of underlying the network. CSF is concerned with how to reach convergence at an underlying network. It aims to provide a smooth and consistent user experience. + +### **II.3 CSF relationship to underlying networks** + +In some CSF instantiations, a network support functional entity (NS-FE) is resident in the underlying network and is administered by the operator of that network. In this case, it is helpful to illustrate the relationship of the NS-FE to the underlying network. + +#### **II.3.1 Example: CSF in an IMS-style network** + +An example of which components of IMS are used by the CSF, and how they extend the IMS specification set is provided below. + +The CSF operates across multiple transport and service control networks. In interacting with IMS, the CSF may act like an application server (AS) and utilize the interfaces defined for an AS. Specifically, an NS-FE uses the ISC interface to interact with the S-CSCF and obtain triggers to discover and modify sessions destined to, or originated by, a user. + +In the IMS release 6 [b-TS 23.228], S-CSCF via the ISC interfaces directly with application servers. The AS selection is based on initial filter criteria (iFC) which are in turn based on predefined service point triggers (SPT) in the home subscriber server (HSS). + +With the addition of a CSF overlay, the trigger criteria will have available a richer set of information through the convergence coordination functional entity (CC-FE), such as session and resource state of the user across multiple, and heterogeneous networks. The CSF also enables identity management features that enable AS to be independent/unaware of the identities of the users in individual networks. + +The CSF allows the session/resource state to be provided to applications via an interface. + +The NS-FE may use the $S_h$ interface to interact with the HSS and to obtain information about the user and devices associated with the user in the IMS domain. + +In large networks with multiple HSSs, the NS-FE may use the $D_h$ interface to interact with the subscription locator function (SLF) to discover an HSS possessing user information. + +The NS-FE uses the $U_t$ interface to interact with the UEs. This interface is used to interact directly with an IMS UE to obtain user inputs, preferences and state of devices from the UE. Alternatively, a CC-FE may use the CSF interface $I_{C-CL}$ to communicate with the client support functional entity (CLS-FE) in the UE to obtain user inputs and preferences and the states of devices from the UE. + +It is also possible for the NS-FE to be incorporated within, for example, the S-CSCF. If implemented in this way, the NS-FE should behave in a manner consistent with the NS-FE-to-CC-FE interface. The NS-FE-IMS interface may disappear from definition, or may need to be enhanced. This is a subject for further study. + +#### **II.3.2 Example: CSF in a wireline-style network** + +An example of which components of a wireline-style network are used by the CSF is provided with reference to the CableLabs' PacketCable Multimedia Specification [b-PKT-SP-MM]. + +The CSF is intended as an overlay across transport and service control networks. In interacting with PCMM, the CSF may act like an application manager (AM) and utilize the interfaces defined for an AM. Specifically, a PCMM-specific NS-FE uses the pkt-mm-3 interface to interact with the PacketCable policy server (PS) and obtain rights for different flows traversing this access network. + +Additionally, the policy server is the point of contact with the CSF for interaction with protected components such as the PacketCable record keeping server (RKS). + +The NS-FE uses the mm-7 interface to interact with the client (a term specified in PCMM). This interface is used by CSF to interact with the client support function (CLS-FE) to directly obtain user inputs and preferences and the state of devices from the client. Alternatively, a CC-FE may use the CSF interface $I_{C-CL}$ to communicate with a client support functional entity (CLS-FE) in the client to obtain user inputs and preferences and the state of devices from the client. + +It is also possible for the NS-FE to be incorporated within, for example, the PCMM PS. If implemented in this way, the NS-FE should behave in a manner consistent with the NS-FE-to-CC-FE interface. The NS-FE-PCMM interface may disappear from definition, or may need to be enhanced. This is a subject for further study. + +# **Appendix III** + +## **Examples of three converged service types** + +(This appendix does not form an integral part of this Recommendation) + +NGN defines multiple service components to provide a wide variety of services. It is the aim of the CSF to present converged services of more than one service across the service components to users in a unified manner. + +Such capabilities to converge services for a subscriber by coordinating, collecting and binding a user's status information from each service component, is defined separately in this CSF Recommendation from the NGN functional architecture. This means current release 1 NGN functional architecture does not fully incorporate the converged control capabilities in each FE. + +This appendix describes several examples of converged type scenarios and also presents the relationships between CSF functions. + +### **III.1 Type 1 example: Converged service in a single service component** + +In the case of a single service component such as of an IP multimedia service component, multiple services must be invoked and coordinated. + +For the originating party, the origination call screen and number translation services are sequentially invoked and processed. Then, for the terminating party, call forwarding on no-answer and voice mail services are invoked in sequence. + +In this case, two originating services and two terminating services are converged for the originating and the terminating subscriber, respectively. + +The CC-FE coordinates the interoperation between multiple services based on the converged service subscription information provided by the NS-FE, shown as part of the SUP-FE (e.g., HSS) in Figure III.1. + +Also, the CC-FE decides upon the converged service control based on the user's presence and preference information from the NS-FE in the SUP-FE or AS-FE (e.g., presence server). For example, the CC-FE may decide not to invoke call forwarding on no-answer, but connect to the voice mail server (VMS) instead. + +Although the APL-SCM-FE function is defined to manage interaction between multiple application services, it only considers coordination based on the iFC through S-CSC-FE. + +However, the CC-FE makes use of more information (e.g., a user's status) collected from various network parts such as presence server, than simple subscription information in iFC. + +![Diagram of a converged service example in a single service component. The diagram shows a central APL-SCM-FE and CC-FE block connected to various service components. On the left, 'Converged services for originating subscriber (IMS)' include 'Origination call screen' and 'Number translation', both represented by AS-FE blocks. On the right, 'Converged services for terminating subscriber (IMS)' include 'Call forwarding on no-answer' and 'Voice mail', also represented by AS-FE blocks. Below these, the 'HSS' contains a 'SUP-FE' and an 'NS-FE' (green box). The 'Presence server' contains a 'SUP-FE or AS-FE' and an 'NS-FE' (green box). A dashed blue line connects the NS-FE of the HSS, the CC-FE, and the NS-FE of the Presence server. The APL-SCM-FE and CC-FE are connected to an 'S-CSCF' block, which is labeled 'S-CSCF'. The S-CSCF is connected to two mobile phones: 'Origination subscriber User A' and 'Terminal subscriber User B'. The entire diagram is enclosed in a dashed box.](f57c7b37d7a05a99618104f390089f03_img.jpg) + +**IP multimedia service component** + +Y.2013(06)\_FIII.1 + +Diagram of a converged service example in a single service component. The diagram shows a central APL-SCM-FE and CC-FE block connected to various service components. On the left, 'Converged services for originating subscriber (IMS)' include 'Origination call screen' and 'Number translation', both represented by AS-FE blocks. On the right, 'Converged services for terminating subscriber (IMS)' include 'Call forwarding on no-answer' and 'Voice mail', also represented by AS-FE blocks. Below these, the 'HSS' contains a 'SUP-FE' and an 'NS-FE' (green box). The 'Presence server' contains a 'SUP-FE or AS-FE' and an 'NS-FE' (green box). A dashed blue line connects the NS-FE of the HSS, the CC-FE, and the NS-FE of the Presence server. The APL-SCM-FE and CC-FE are connected to an 'S-CSCF' block, which is labeled 'S-CSCF'. The S-CSCF is connected to two mobile phones: 'Origination subscriber User A' and 'Terminal subscriber User B'. The entire diagram is enclosed in a dashed box. + +**Figure III.1 – Converged service example in a single service component** + +### III.2 Type 2 example: Converged service in multiple service components (PIEA + IMS) + +In this example, service convergence is achieved across multiple service components, the first being a PSTN/ISDN emulation (PIEA) service component and the second being an IP multimedia service component. + +User A has both a POTS and IP phone and subscribes two services, caller ID and number translation. Through service convergence, it should be possible to access the same services from each phone. + +When user A requests a call from the POTS phone, the basic caller ID and number translation services in PIEA are invoked. In the case that user A requests a call using the IP video phone, the multimedia caller ID and number translation services will be provided by IMS. + +Since the user subscribes over multiple service components, the interaction management function of the CC-FE is required between different service components or administrative domains. + +To retrieve each profile for the user, the CC-FE refers to the NS-FE in the PIEA SUP-FE or the NS-FE in the IMS SUP-FE (e.g., HSS), according to the user's network. + +![Figure III.2 – Converged service example in multiple service components (PIEA + IMS). The diagram illustrates a converged network architecture. At the top, two service components are shown: 'PSTN/ISDN emulation service component' on the left and 'IP multimedia service component' on the right. A dashed oval labeled 'Converged services for PIEA and IMS subscriber' encloses four AS-FE blocks: two for CID and Number translation in the PSTN component, and two for Multimedia CID and Number translation in the IP component. These connect to a central APL-SCM-FE block. Below this, a CC-FE block is connected to an NS-FE block on the left (labeled 'PIEA User profile' with a UPF block) and an NS-FE block on the right (labeled 'HSS' with a SUP-FE block). The left NS-FE connects to an AGC-FE block (labeled 'Call server'), which connects to a POTS phone. The right NS-FE connects to an S-CSCF block (labeled 'S-CSCF'), which connects to a Video phone. A dashed line connects the two NS-FE blocks. At the bottom, 'User A' is indicated with lines pointing to the POTS and Video phone. A reference 'Y.2013(06)_F.11.2' is in the bottom right corner.](e64c7b989e5bdb2708cd7aefd18b06e1_img.jpg) + +Figure III.2 – Converged service example in multiple service components (PIEA + IMS). The diagram illustrates a converged network architecture. At the top, two service components are shown: 'PSTN/ISDN emulation service component' on the left and 'IP multimedia service component' on the right. A dashed oval labeled 'Converged services for PIEA and IMS subscriber' encloses four AS-FE blocks: two for CID and Number translation in the PSTN component, and two for Multimedia CID and Number translation in the IP component. These connect to a central APL-SCM-FE block. Below this, a CC-FE block is connected to an NS-FE block on the left (labeled 'PIEA User profile' with a UPF block) and an NS-FE block on the right (labeled 'HSS' with a SUP-FE block). The left NS-FE connects to an AGC-FE block (labeled 'Call server'), which connects to a POTS phone. The right NS-FE connects to an S-CSCF block (labeled 'S-CSCF'), which connects to a Video phone. A dashed line connects the two NS-FE blocks. At the bottom, 'User A' is indicated with lines pointing to the POTS and Video phone. A reference 'Y.2013(06)\_F.11.2' is in the bottom right corner. + +**Figure III.2 – Converged service example in multiple service components (PIEA + IMS)** + +### III.3 Type 3 example: Converged service with other network – IMS + Internet IM server + +This example shows the converged service for multiple service components of an IP multimedia service component and an unspecified "other network", such as the Internet. + +Figure III.3 (a) shows VoIP + IM converged service scenario: + +- User A has a video phone and an Internet-connected PC on which he/she uses an instant messenger (or calendar, or similar service). +- When user A's phone establishes a call connection, the 'busy' status is notified to CC-FE. The CC-FE sends that information to an NS-FE in the instant messenger or calendar server. The user's status of the IM or calendar is changed to be 'busy'. +- Conversely, when the user A makes the status 'busy' in the IM or calendar, it informs the CC-FE, and the CC-FE notifies the NS-FE in S-CSCF-FE. Then user A's video phone status becomes busy. Therefore, if an incoming call arrives, the calling party receives the busy tone for user A. +- As an alternative interworking method with IM service, the CLS-FE in the user's PC may notify the user status to the CC-FE. + +Figure III.3 (b) illustrates game + IM converged service scenario: + +- When user A connects to a game server, three alternative notifications to CC-FE are possible: (1) from the CLS-FE on the phone; (2) from the ES-FE on the edge node; (3) from the NS-FE on the game server. + +- For (2), the ES-FE in the edge node FE monitors the video phone's out-stream packets to the network based on the source IP and/or port number. Detecting such packets, ES-FE notifies CC-FE that user A's video phone is busy (for any 'data' services other than VoIP) and then CC-FE notifies NS-FE on the IM server, which becomes aware that user A's status is 'busy'. +- Although it is not shown in the figure, the CC-FE may reside on the terminal for the enterprise, home network services and peer-to-peer service, such as personal broadcast service. +- To allow intercommunication between these two networks, the CSF glues the NS-FE/CC-FE/CLS-FE/ES-FE in each network through CC-FE. + +![Figure III.3 – Converged service example with other networks. The diagram is divided into two parts: (a) VoIP + Internet IM and (b) Game + Internet IM. Both parts show an 'IP multimedia service component' and an 'Other network'. In part (a), the IP component includes HSS, SUP-FE, S-CSCF, NS-FE, CC-FE, and a video phone. The other network includes an IM/calendar server, NS-FE (CC-FE), and CLS-FE connected to a PC/PDA. In part (b), the IP component includes CC-FE, Edge-node-FE, ES-FE, and a video phone. The other network includes a game server, IM server, NS-FE, and CLS-FE connected to a PC/PDA. Dashed lines represent interfaces between CSF functions.](5eb69662cc4fa7d0d49b4eb22951c204_img.jpg) + +**IP multimedia service component** + +**Other network** + +Converged services of VoIP + IM + +HSS +SUP-FE + +APL-SCM-FE +CC-FE + +S-CSCF +NS-FE + +IM, calendar server +NS-FE (CC-FE) + +CLS-FE + +Video phone + +PC, PDA + +User A + +a) VoIP + Internet IM + +**IP multimedia service component** + +**Other network** + +Converged services of game + IM + +Game server +NS-FE + +IM server +NS-FE + +APL-SCM-FE +CC-FE + +Edge-node-FE +ES-FE + +CLS-FE + +Video phone + +PC, PDA + +User A + +b) Game + Internet IM + +Y.2013(06)\_FIII.3 + +Figure III.3 – Converged service example with other networks. The diagram is divided into two parts: (a) VoIP + Internet IM and (b) Game + Internet IM. Both parts show an 'IP multimedia service component' and an 'Other network'. In part (a), the IP component includes HSS, SUP-FE, S-CSCF, NS-FE, CC-FE, and a video phone. The other network includes an IM/calendar server, NS-FE (CC-FE), and CLS-FE connected to a PC/PDA. In part (b), the IP component includes CC-FE, Edge-node-FE, ES-FE, and a video phone. The other network includes a game server, IM server, NS-FE, and CLS-FE connected to a PC/PDA. Dashed lines represent interfaces between CSF functions. + +**Figure III.3 – Converged service example with other networks** + +The dashed lines in Figure III.3 correspond to the interfaces between CSF functions. + +# Appendix IV + +## CC-FE to CC-FE interworking description models + +(This appendix does not form an integral part of this Recommendation) + +The converged services framework (CSF) is an architectural framework intended to provide converged NGN services. The CC-FE (convergence coordination functional entity) is a core component of the CSF and it supports coordination control and processing of necessary information in order to provide converged services. + +Typically, the converged services are thought to be provided by a service provider in an administrative domain and, in that case, there will be one CC-FE in a domain. + +By relating multiple CC-FEs, it is possible to provide converged services across domains; with the CC-FE to CC-FE relationship, it is possible to integrate the converged services of multiple and distributed service providers, market segments and/or administrative domains. + +In order to describe the usefulness of interworking between CC-FEs, three convergence models are presented. + +### IV.1 Hierarchical convergence model + +In a hierarchical distribution, the span of control for CC-FE is organized into a hierarchy. Figure IV.1 depicts a hierarchical model of the convergence architecture. In this case, services integrated by lower level CC-FEs are accessible and under the control of a higher level CC-FE. + +For example, the personal services at the lowest level provide individual feature services, such as IM and video phone, to users. The project services of the second level hierarchy will include project features, such as conference call service, and it also includes personal-level services. For a subscriber with the converged services provided at the company level, CC-FE will include all the services integrated by the lower level CC-FEs: it includes company, project and personal features. + +In this way, the CC-FE can converge lower layer converged services. + +![Figure IV.1 – Hierarchical convergence model diagram](e97d663314aff9c29bf8971323e6539e_img.jpg) + +The diagram illustrates a hierarchical convergence model with three levels of service integration. At the base, three service categories are shown, each enclosed in a dashed oval: 'Personal services' (e.g., IM, video phone), 'Project service' (e.g., conference call), and 'Company services' (e.g., announcement, emergency call). Each category contains three functional entities: CLS-FE, NS-FE, and ES-FE. Above each of these base groups is a 'CC-FE' (Convergence Coordination Functional Entity) box, which is connected to its respective CLS-FE, NS-FE, and ES-FE boxes. A 'CP-FE' (Convergence Policy Functional Entity) box is positioned above each 'CC-FE' box. The three 'CC-FE' boxes are interconnected in a hierarchical manner: the 'Personal services' CC-FE connects to the 'Project service' CC-FE, and the 'Project service' CC-FE connects to the 'Company services' CC-FE. Additionally, each 'CC-FE' box is connected to its own 'CP-FE' box. The 'Company services' CC-FE is also connected to a 'CP-FE' box. The diagram is labeled 'Y.2013(06)\_FIV-1' in the bottom right corner. + +Figure IV.1 – Hierarchical convergence model diagram + +Figure IV.1 – Hierarchical convergence model + +### IV.2 Master-slave convergence model + +In a master-slave distribution, a single CC-FE acts as a master controlling a collection of CC-FE slaves. Figure IV.2 shows the master-slave convergence model. The master CC-FE can control and provide converged services including services that a slave CC-FE provides. This is a typical way for network/service operators connecting and integrating with third party service providers. + +![Figure IV.2 – Master-slave convergence model diagram](0b7849dae424b0dd33e6386d2384643a_img.jpg) + +The diagram illustrates the Master-slave convergence model. It features three main service groups, each represented by a dashed oval containing three yellow boxes labeled CLS-FE, NS-FE, and ES-FE. Above each oval is a yellow box labeled CC-FE. To the left of each CC-FE box is a white box labeled CP-FE. The connections are as follows: + + +- The first group, labeled 'Third-party messaging service e.g., IM, e-mail', has its CP-FE connected to its CC-FE, which is then connected to the CC-FE of the third group. +- The second group, labeled 'Third party contents service e.g., music, movie', has its CP-FE connected to its CC-FE, which is then connected to the CC-FE of the third group. +- The third group, labeled 'Main operator services e.g., VoIP, MMoIP', has its CP-FE connected to its CC-FE, which is then connected to the CC-FE of the first group. + + A reference code 'Y.2013(06)\_FIV-2' is located at the bottom right of the diagram. + +Figure IV.2 – Master-slave convergence model diagram + +**Figure IV.2 – Master-slave convergence model** + +### IV.3 Peer-to-peer convergence model + +In peer-to-peer distribution, all CC-FEs can access and coordinate the services integrated by their peers. This type of distribution typically bundles services to specific needs of a market segment. Figure IV.3 illustrates the peer-to-peer convergence architecture. In this case, there are three classes of converged services integrated for mobile, fixed and data service operators. With these relationships, operators can support bundled services of each operator. + +![Figure IV.3 – Peer-to-peer convergence model diagram](838c31609fac483fa2c01c7896a2fd6d_img.jpg) + +The diagram illustrates the Peer-to-peer convergence model. It features three main service groups, each represented by a dashed oval containing three yellow boxes labeled CLS-FE, NS-FE, and ES-FE. Above each oval is a yellow box labeled CC-FE. To the left of each CC-FE box is a white box labeled CP-FE. The connections are as follows: + + +- The three CC-FE boxes are connected to each other in a peer-to-peer fashion, forming a triangle with lines connecting each pair of CC-FE boxes. +- Each CP-FE box is connected to its corresponding CC-FE box. +- The first group, labeled 'Mobile operator service e.g., SMS, VoIP', is connected to the first CC-FE. +- The second group, labeled 'Fixed operator service e.g., video phone', is connected to the second CC-FE. +- The third group, labeled 'Data service operator e.g., access, messenger, email', is connected to the third CC-FE. + + A reference code 'Y.2013(06)\_FIV-3' is located at the bottom right of the diagram. + +Figure IV.3 – Peer-to-peer convergence model diagram + +**Figure IV.3 – Peer-to-peer convergence model** + +Although it is not exemplified, the case of CC-FE positioned in the NGN terminal is also possible in all convergence models presented. + +# Appendix V + +## CSF configuration models + +(This appendix does not form an integral part of this Recommendation) + +The CSF is an architecture which can be configured in different ways to accommodate existing and future access and service networks. This clause provides two typical examples of the possible physical locations of the CC-FE and its support functions (CP-FE, NS-FE, ES-FE and CLS-FE). Figures V.1 and V.2 further convey the logical and physical communication paths of the CC-FE to its support functions, and the logical and physical communication paths for the CC-FE to the access networks and their applications. + +The first CSF example shown is for coordination between a PSTN and a WMAN network. + +![Diagram illustrating CSF coordination for PSTN and WMAN networks. The diagram shows a central IP network cloud connected to two main network clouds: PSTN network on the left and WMAN network on the right. Above the IP network is a CC-FE (Control Function Element) block. Below it is a CP-FE (Control Plane Function Element) block. The PSTN network contains an NS-FE (Network Service Function Element) block, which is connected to SCP (Service Control Point), STP (Service Transfer Point), and SSP (Service Switching Point) blocks. The WMAN network contains an ES-FE (Edge Service Function Element) block, which is connected to AP(2) (Access Point) blocks, and a CLS-FE (Class of Service Function Element) block. Both networks have Client blocks. Applications are shown at the top, connected to the CC-FE. The diagram uses three types of lines: solid black for IP (Physical), dashed red for CSF (Physical), and dash-dot blue for CSF (Logical).](9a14684f8ae1345c6efea6f5994c730c_img.jpg) + +Legend: + +- IP (Physical) +- - - CSF (Physical) +- . - CSF (Logical) + +Y.2013(06)\_FV-1 + +Diagram illustrating CSF coordination for PSTN and WMAN networks. The diagram shows a central IP network cloud connected to two main network clouds: PSTN network on the left and WMAN network on the right. Above the IP network is a CC-FE (Control Function Element) block. Below it is a CP-FE (Control Plane Function Element) block. The PSTN network contains an NS-FE (Network Service Function Element) block, which is connected to SCP (Service Control Point), STP (Service Transfer Point), and SSP (Service Switching Point) blocks. The WMAN network contains an ES-FE (Edge Service Function Element) block, which is connected to AP(2) (Access Point) blocks, and a CLS-FE (Class of Service Function Element) block. Both networks have Client blocks. Applications are shown at the top, connected to the CC-FE. The diagram uses three types of lines: solid black for IP (Physical), dashed red for CSF (Physical), and dash-dot blue for CSF (Logical). + +Figure V.1 – Example 1, CSF coordination for PSTN and WMAN networks + +The second CSF example shown is for coordination between a PSTN and a cable-based call control network. + +![Diagram illustrating CSF coordination for PSTN and cable networks. The diagram shows three main components: Applications, IP network, and two cloud-based networks (PSTN network and Cable-based call control network). Applications are connected to CC-FE (Call Control Function Element) in the IP network. CC-FE is connected to CP-FE (Call Processing Function Element) in the IP network. CP-FE is connected to NS-FE (Network Signaling Function Element) in the PSTN network. NS-FE is connected to SCP (Service Control Point) and STP (Signaling Transfer Point) in the PSTN network. SCP and STP are connected to SSP (Session Setup Point) in the PSTN network. SSP is connected to Clients in the PSTN network. The IP network is connected to ES-FE (Edge Signaling Function Element) in the Cable-based call control network. ES-FE is connected to CLS-FE (Core Line Signaling Function Element) in the Cable-based call control network. CLS-FE is connected to Clients in the Cable-based call control network. The diagram also shows CMS (Call Management System) and AAA (Authentication, Authorization, and Accounting) in the Cable-based call control network. A legend at the bottom indicates: IP (Physical) (solid line), CSF (Physical) (dashed line), and CSF (Logical) (dotted line).](b05bae46f7079e5c9b1da38adb2319e8_img.jpg) + +Legend: + +- IP (Physical) (solid line) +- CSF (Physical) (dashed line) +- CSF (Logical) (dotted line) + +Diagram illustrating CSF coordination for PSTN and cable networks. The diagram shows three main components: Applications, IP network, and two cloud-based networks (PSTN network and Cable-based call control network). Applications are connected to CC-FE (Call Control Function Element) in the IP network. CC-FE is connected to CP-FE (Call Processing Function Element) in the IP network. CP-FE is connected to NS-FE (Network Signaling Function Element) in the PSTN network. NS-FE is connected to SCP (Service Control Point) and STP (Signaling Transfer Point) in the PSTN network. SCP and STP are connected to SSP (Session Setup Point) in the PSTN network. SSP is connected to Clients in the PSTN network. The IP network is connected to ES-FE (Edge Signaling Function Element) in the Cable-based call control network. ES-FE is connected to CLS-FE (Core Line Signaling Function Element) in the Cable-based call control network. CLS-FE is connected to Clients in the Cable-based call control network. The diagram also shows CMS (Call Management System) and AAA (Authentication, Authorization, and Accounting) in the Cable-based call control network. A legend at the bottom indicates: IP (Physical) (solid line), CSF (Physical) (dashed line), and CSF (Logical) (dotted line). + +**Figure V.2 – Example 2, CSF coordination for PSTN and cable networks** + +# Bibliography + +- [b-TS 23.228] 3GPP TS 23.228 (2004), *IP Multimedia Subsystem (IMS); Stage 2, Release 6*. +- [b-ES 202 391] ETSI ES 202 391-[1-14] V1.2.1 (2006), *Open Service Access (OSA), Parlay X Web Services, Parts 1-14*. +- [b-ES 203 915] ETSI ES 203 915-[1-15] V1.1.1 (2005), *Open Service Access (OSA), Application Programming Interface (API), Parts 1-15*. +- [b-PKT-SP-MM] PKT-SP-MM-I03-051221 PacketCable (2005), *PacketCable™ Multimedia Specification*. + + + + + +# SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|--------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/Y/T-REC-Y.2023-201204-I_PDF-E/043e64d41a3368d138ace3816fd26469_img.jpg b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/043e64d41a3368d138ace3816fd26469_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..dfc0e9d24d1f42b821771dcbc43d46c3ae14187a --- /dev/null +++ b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/043e64d41a3368d138ace3816fd26469_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:6370f0ba2617e90bc84354a153aedcae17d73052daadad2a0ba137ddfcba9ee8 +size 33251 diff --git a/marked/Y/T-REC-Y.2023-201204-I_PDF-E/0ee9d674085524d589646a6c3fb21ec3_img.jpg b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/0ee9d674085524d589646a6c3fb21ec3_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..679a09a37659d44ff86c3c00cb3fc3d27bbe9b03 --- /dev/null +++ b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/0ee9d674085524d589646a6c3fb21ec3_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:63f97796f107e367f6d71cd3f4380730476c456bbd07bfd7a8693a91ee6be9a8 +size 45422 diff --git a/marked/Y/T-REC-Y.2023-201204-I_PDF-E/157e8c1d80a02c8eee893c2ea60a77a8_img.jpg b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/157e8c1d80a02c8eee893c2ea60a77a8_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..99dd5c0cdc105c3d7034f78dd3c7cf3e5040b771 --- /dev/null +++ b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/157e8c1d80a02c8eee893c2ea60a77a8_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:9492500c6b90933299b58a941a4ece2e9fa2aa0bd2e855a23c67af5933779d78 +size 99905 diff --git a/marked/Y/T-REC-Y.2023-201204-I_PDF-E/171115f072e42b379238ed0dd438e9d7_img.jpg b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/171115f072e42b379238ed0dd438e9d7_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..65233793fcf47635c3fefe518e6ee53732ca9a0d --- /dev/null +++ b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/171115f072e42b379238ed0dd438e9d7_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:d413f30b1c123a2db198b325053384a27645f0cf4f48199464c618512dce8d70 +size 32311 diff --git a/marked/Y/T-REC-Y.2023-201204-I_PDF-E/2eb23c2210154279f8013a1594fbcc5a_img.jpg b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/2eb23c2210154279f8013a1594fbcc5a_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..404ce5c426fc7b3e649de244bfec3347bd706751 --- /dev/null +++ b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/2eb23c2210154279f8013a1594fbcc5a_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:93c0a611e85171acb772e597cd7b697bd1976d391053dde196f2b347c755802c +size 46701 diff --git a/marked/Y/T-REC-Y.2023-201204-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..0680755371c85db3c6963d5f8b7209e4fbace758 --- /dev/null +++ b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:5dc3ef3d1afca1b72302359767024d599a43d7d02a7103e327498641ad04b659 +size 70949 diff --git a/marked/Y/T-REC-Y.2023-201204-I_PDF-E/3cc095fb84e92690c9d49d3e17c0f1dc_img.jpg b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/3cc095fb84e92690c9d49d3e17c0f1dc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..1d9af6dcd9c26f780ef782ddeffa421616dbf424 --- /dev/null +++ b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/3cc095fb84e92690c9d49d3e17c0f1dc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:288ea88bd96084567fb9e6d5088ace656e475287a993777a51ecd1ca269843b4 +size 65535 diff --git a/marked/Y/T-REC-Y.2023-201204-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..81ef5b084237cb484511f773e4b6a24f27617e90 --- /dev/null +++ b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:8d6d3c590272082e92a64066380602983a8b4aee3cc8b321434b2cb2d43035e9 +size 198177 diff --git a/marked/Y/T-REC-Y.2023-201204-I_PDF-E/58f4167687de8d7339594e5f6fbe0bc6_img.jpg b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/58f4167687de8d7339594e5f6fbe0bc6_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..fbc7c726f0478111fe7d8cece24232616203c45f --- /dev/null +++ b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/58f4167687de8d7339594e5f6fbe0bc6_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:2317f6c47962bf5be913c7a2c8bf2b05f36b9aa04eaab65edd953297e742118c +size 36933 diff --git a/marked/Y/T-REC-Y.2023-201204-I_PDF-E/7133ccf78043568ca62ecbcd43628a4a_img.jpg b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/7133ccf78043568ca62ecbcd43628a4a_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..6c50aa507c1b35cc5050cf80d47ef0373785c5ef --- /dev/null +++ b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/7133ccf78043568ca62ecbcd43628a4a_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:ca3a26acdd1e11d86358368f128d2b080969b0dd63c9a4600d258d7a08aced63 +size 32576 diff --git a/marked/Y/T-REC-Y.2023-201204-I_PDF-E/77959075c823bb5169480d7b8ff82a63_img.jpg b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/77959075c823bb5169480d7b8ff82a63_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..42da18709ac4171171c88e4ff8de0b89c35cbe6d --- /dev/null +++ b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/77959075c823bb5169480d7b8ff82a63_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:19fc72dae2c5ca6503c7cb79eebaa51da5c2cbde58316a1a722b1a53f4a1cdd9 +size 91460 diff --git a/marked/Y/T-REC-Y.2023-201204-I_PDF-E/7ae836e598020d937ed1478c2ef13025_img.jpg b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/7ae836e598020d937ed1478c2ef13025_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..14cb7533c8535daed34f83e6dd49273891bc2796 --- /dev/null +++ b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/7ae836e598020d937ed1478c2ef13025_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:7f74338101c0afdb1068f57cdf6b01b77dd39d1ae0d699067005d571989537e9 +size 66724 diff --git a/marked/Y/T-REC-Y.2023-201204-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..764a82687969ec15e48db91910bde9b62ee68cca --- /dev/null +++ b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:d2a1a0ee67a1cae8c705d7d87ae4ca44bf72d7e565432ceb25ccb352a8d78dc5 +size 6613 diff --git a/marked/Y/T-REC-Y.2023-201204-I_PDF-E/8d325fc12b494e42c9ea7ed2a7f327a6_img.jpg b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/8d325fc12b494e42c9ea7ed2a7f327a6_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..76612a4fe3c39e3112d3e3312486e8c7cb86792b --- /dev/null +++ b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/8d325fc12b494e42c9ea7ed2a7f327a6_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:b2d1daca16eec4034f59da8cc0973ada625c024c726edb86f498f9aff607ef7f +size 45790 diff --git a/marked/Y/T-REC-Y.2023-201204-I_PDF-E/933ecd14c858bf3fc919222d8e357bc8_img.jpg b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/933ecd14c858bf3fc919222d8e357bc8_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..7dd925325d0fb27cf56154fcbeaa4c4418ff8d63 --- /dev/null +++ b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/933ecd14c858bf3fc919222d8e357bc8_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:315b21ea5068d6150d5ffe0eaf3330496c9e3dc33e9c6d63e9ac61202f5d5c9e +size 68735 diff --git a/marked/Y/T-REC-Y.2023-201204-I_PDF-E/9a5927586a691c4908aa2cf98bd47ebb_img.jpg b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/9a5927586a691c4908aa2cf98bd47ebb_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..019d8e6573eba2602fa176bfb1e49a447a57d43c --- /dev/null +++ b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/9a5927586a691c4908aa2cf98bd47ebb_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:b22a9cac6987cf3c23780f2963e556da2ab58c31e43bc6a98fa00992a1c70072 +size 95182 diff --git a/marked/Y/T-REC-Y.2023-201204-I_PDF-E/a24e89a6fe9bb70c83f8bf5202baba95_img.jpg b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/a24e89a6fe9bb70c83f8bf5202baba95_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..328d0ed5844789b35f713f73267beed1c6faa74a --- /dev/null +++ b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/a24e89a6fe9bb70c83f8bf5202baba95_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:ac8a90777a24cc346b6ab08d29a4a43b8a44251e3f7bf4f4d86431b756e8b590 +size 17977 diff --git a/marked/Y/T-REC-Y.2023-201204-I_PDF-E/b235edb1dbe659e2782c9a0e47775ca4_img.jpg b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/b235edb1dbe659e2782c9a0e47775ca4_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..88b3855313046737dc7aab9ac8958eeda9fc680a --- /dev/null +++ b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/b235edb1dbe659e2782c9a0e47775ca4_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:abfbf29e0f69ca3d73520005844e86d647d76b0964a795f13ce3d74a85c44c7f +size 81763 diff --git a/marked/Y/T-REC-Y.2023-201204-I_PDF-E/c914f51f4427bc672dd0526cfc90ebe9_img.jpg b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/c914f51f4427bc672dd0526cfc90ebe9_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..61f89524025f8633de49c9fb9bcced896a5dd2c7 --- /dev/null +++ b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/c914f51f4427bc672dd0526cfc90ebe9_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:300bfe54f3d4fecb034241af7e96a0133899585f2bffb5d2293a556c2b5c0c56 +size 62447 diff --git a/marked/Y/T-REC-Y.2023-201204-I_PDF-E/dcb5711d118ae6753b0e12f86eda37db_img.jpg b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/dcb5711d118ae6753b0e12f86eda37db_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..8d0823b39b31a447b38e916294040b1c745995d2 --- /dev/null +++ b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/dcb5711d118ae6753b0e12f86eda37db_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:2ce2309245931d1c02ddcf8be6733a6f9fa40ea7b00d9a58ea6f3658a423a663 +size 44151 diff --git a/marked/Y/T-REC-Y.2023-201204-I_PDF-E/e451401f8fa77b466f401d5fce15b26c_img.jpg b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/e451401f8fa77b466f401d5fce15b26c_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..3f26fc4b343197489500e583f40f1ac53b2d9603 --- /dev/null +++ b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/e451401f8fa77b466f401d5fce15b26c_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:0cd974ae6be6cb66bdaeeb83c33cab2deaec380854b9297629fc10506eabe6a6 +size 46739 diff --git a/marked/Y/T-REC-Y.2023-201204-I_PDF-E/e69b9188aa2c14ec6b21c83f711fef65_img.jpg b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/e69b9188aa2c14ec6b21c83f711fef65_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..67959a7991755f2fb757a9510ca79e941f07099a --- /dev/null +++ b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/e69b9188aa2c14ec6b21c83f711fef65_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:e578f36bd695d360f17b35bfb09dc81df46868d5f1fea53d03d546c2620e7778 +size 31007 diff --git a/marked/Y/T-REC-Y.2023-201204-I_PDF-E/e9314c83043183351ed74908e9bf2f90_img.jpg b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/e9314c83043183351ed74908e9bf2f90_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..949875a030485310efbd9161f44169e3169e3782 --- /dev/null +++ b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/e9314c83043183351ed74908e9bf2f90_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:84791ca7b39f777c6c6d712a7c70e3c09b56e406c011be27b8b45f39725552f6 +size 87765 diff --git a/marked/Y/T-REC-Y.2023-201204-I_PDF-E/f57c7b37d7a05a99618104f390089f03_img.jpg b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/f57c7b37d7a05a99618104f390089f03_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..d023a5b9c967c2102eb386bf4fdb3e6ab27fd1dd --- /dev/null +++ b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/f57c7b37d7a05a99618104f390089f03_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:deb8b709d3d8962cff3170539028b927c2751e5bfc8bc64f28c2388ad5b2ee8f +size 43879 diff --git a/marked/Y/T-REC-Y.2023-201204-I_PDF-E/fa01531ea2c45beeb4036005da3037a4_img.jpg b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/fa01531ea2c45beeb4036005da3037a4_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..83385ff2a39fb2bcc3910f517ae2a419c0955eee --- /dev/null +++ b/marked/Y/T-REC-Y.2023-201204-I_PDF-E/fa01531ea2c45beeb4036005da3037a4_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:79f778fe5c927defac3621c565366abc8928e0d5d17f9e11af4adc76c0480a54 +size 45420 diff --git a/marked/Y/T-REC-Y.2027-201207-I_PDF-E/2ae3eae1bd80a90f192f568ae246a9a6_img.jpg b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/2ae3eae1bd80a90f192f568ae246a9a6_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..c66d4c0a9dedb29d9e3a1bbcd64a5da26c844ae9 --- /dev/null +++ b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/2ae3eae1bd80a90f192f568ae246a9a6_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:2ad902d7403ab527744b0db4c3269f69a9a9d7d4521295c333662203188e2d4c +size 60091 diff --git a/marked/Y/T-REC-Y.2027-201207-I_PDF-E/318886a86a1dcc59e1fc83db6f157c60_img.jpg b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/318886a86a1dcc59e1fc83db6f157c60_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..93085b93b0c19a877f80694173d353d67619ba6e --- /dev/null +++ b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/318886a86a1dcc59e1fc83db6f157c60_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:8577cebc7ebd3af7afc059e470e6191177d7fc406900d1fe6e137a2cd3ceaaf7 +size 59162 diff --git a/marked/Y/T-REC-Y.2027-201207-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..bd697ade0d78b48da93373f127c0d25dbbb7536f --- /dev/null +++ b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:061ee0c4309c25b0b524dbc9ae84a60dc516160a376fab7864054d3602f26491 +size 75739 diff --git a/marked/Y/T-REC-Y.2027-201207-I_PDF-E/3cc095fb84e92690c9d49d3e17c0f1dc_img.jpg b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/3cc095fb84e92690c9d49d3e17c0f1dc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..1b360f82f05195e240c96edfcfdfc584c4bf676a --- /dev/null +++ b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/3cc095fb84e92690c9d49d3e17c0f1dc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:b0f496a5908c10da67b0ab0f677709ea558d720cffd5134e87d2b61ede112cf8 +size 78567 diff --git a/marked/Y/T-REC-Y.2027-201207-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..a353b30c78d9d0568ea6973218f4c95d57e5935e --- /dev/null +++ b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:607c11597dfda0cfb6fd89c2fed9f9d4c7db39d0ed3100aa760a3e122c682f17 +size 57219 diff --git a/marked/Y/T-REC-Y.2027-201207-I_PDF-E/4b87467ad9642943235f48f7d4b59449_img.jpg b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/4b87467ad9642943235f48f7d4b59449_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..f69b870633f60291c052aff9b2aca1e03ea08dcc --- /dev/null +++ b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/4b87467ad9642943235f48f7d4b59449_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:6dac399e37ce3057a9d9796323891bb81821710a1ad299a38c0b681c06cea424 +size 126203 diff --git a/marked/Y/T-REC-Y.2027-201207-I_PDF-E/744acfe8d4e31bcf03f95714c2f6e567_img.jpg b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/744acfe8d4e31bcf03f95714c2f6e567_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..be091cfcdb2d4c37b54428f1d3f6aadc0b2674ed --- /dev/null +++ b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/744acfe8d4e31bcf03f95714c2f6e567_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:f54d694586b7278591a8a0d6064e8f69a4a38559ab6062cf764257c522f93ff0 +size 106143 diff --git a/marked/Y/T-REC-Y.2027-201207-I_PDF-E/844077b3034f0030b404207db0ad76b4_img.jpg b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/844077b3034f0030b404207db0ad76b4_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..3876611048524c94b224af762821dfb3c9933112 --- /dev/null +++ b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/844077b3034f0030b404207db0ad76b4_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:5bf7041c3e3016561ecea5f4ab149f15eab1928bc322490ea7b9ba8ad1af09be +size 116658 diff --git a/marked/Y/T-REC-Y.2027-201207-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..8e6083443744bfcf0189b6a1a40a7196a3719d21 --- /dev/null +++ b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:c42d49668d54f7c4a93629e0336a5627f97bd26d2b806a856c675e51c4c8cffc +size 6436 diff --git a/marked/Y/T-REC-Y.2027-201207-I_PDF-E/8d325fc12b494e42c9ea7ed2a7f327a6_img.jpg b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/8d325fc12b494e42c9ea7ed2a7f327a6_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..fbb338517c301b52c259564e2249078d81fedf72 --- /dev/null +++ b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/8d325fc12b494e42c9ea7ed2a7f327a6_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:9f2872d35bb85205b13bb0df62f4a72059b77eaeecc02c7ffa84989f2817a8b1 +size 60821 diff --git a/marked/Y/T-REC-Y.2027-201207-I_PDF-E/90ddb84c323b956e2d50a54d3f870566_img.jpg b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/90ddb84c323b956e2d50a54d3f870566_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..ea3b9b0b26b1c9d073e0552f8d692b7305552d67 --- /dev/null +++ b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/90ddb84c323b956e2d50a54d3f870566_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:87055fca65862561128212c6616f03408ff00d13090c42488707c6df13c3e008 +size 45603 diff --git a/marked/Y/T-REC-Y.2027-201207-I_PDF-E/9c6461e1e94afae4dec455e69a2ce152_img.jpg b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/9c6461e1e94afae4dec455e69a2ce152_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..4bf9d862cb6c2c512652c4f4037340ee74584089 --- /dev/null +++ b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/9c6461e1e94afae4dec455e69a2ce152_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:359050f62be14e36a67bac623e63bf112f4d2d51bb00844290b2baba6e93136e +size 295681 diff --git a/marked/Y/T-REC-Y.2027-201207-I_PDF-E/a33da0f14e456f92539ce3e9b7d81f9a_img.jpg b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/a33da0f14e456f92539ce3e9b7d81f9a_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..8ff98029e378f7b83a1df149b6e1037094a9d1c1 --- /dev/null +++ b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/a33da0f14e456f92539ce3e9b7d81f9a_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:8e57fc2126223f99dbc22a1d19f5e4eb640da9950bebd4b6ef70391a7b7a1e4e +size 27084 diff --git a/marked/Y/T-REC-Y.2027-201207-I_PDF-E/b235edb1dbe659e2782c9a0e47775ca4_img.jpg b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/b235edb1dbe659e2782c9a0e47775ca4_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..810320b025ef40139f9f583da6e628e3c73732ab --- /dev/null +++ b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/b235edb1dbe659e2782c9a0e47775ca4_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:eb74fd8e3940460b28cd3c6265f0a3fba29d54a9f029ad03218ce0c93533e7ac +size 61656 diff --git a/marked/Y/T-REC-Y.2027-201207-I_PDF-E/cab0834804fb031b43865554cc8d06ab_img.jpg b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/cab0834804fb031b43865554cc8d06ab_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..fc8b6dd12a499e45d54f05a8685a7e8e43ad6602 --- /dev/null +++ b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/cab0834804fb031b43865554cc8d06ab_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:df38277eeff7f6bb0f200aa5c9b460f5af58a98bd300a963f3795ed65dbe7f4e +size 38474 diff --git a/marked/Y/T-REC-Y.2027-201207-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..97fc3d64873772cabc67eff3a73c21d8c734587e --- /dev/null +++ b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:c9da0c9a375bcbe6b7c1a08928f776aee18b3419eda8c85586d4dfcd141bd23e +size 169904 diff --git a/marked/Y/T-REC-Y.2027-201207-I_PDF-E/dcb5711d118ae6753b0e12f86eda37db_img.jpg b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/dcb5711d118ae6753b0e12f86eda37db_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..e866f2830993dba626191be6e584c631141e2b55 --- /dev/null +++ b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/dcb5711d118ae6753b0e12f86eda37db_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:53fe3403280cdf79828b2287a9145d5605f4338704b1c7b778b890de7196461f +size 103605 diff --git a/marked/Y/T-REC-Y.2027-201207-I_PDF-E/e05b36c0d46549e681ce6581422c66b2_img.jpg b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/e05b36c0d46549e681ce6581422c66b2_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..9c70b1062ab6b1489efd33920ecb2762e6fb79bd --- /dev/null +++ b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/e05b36c0d46549e681ce6581422c66b2_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:e1db18a59efeb921880a77bec66c24a996e7525d1e574160410aff041978f156 +size 24228 diff --git a/marked/Y/T-REC-Y.2027-201207-I_PDF-E/f4fdd410cdb84df81274da55721e56fb_img.jpg b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/f4fdd410cdb84df81274da55721e56fb_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..12608b95955268fb2132c4b6b065c071110a94ea --- /dev/null +++ b/marked/Y/T-REC-Y.2027-201207-I_PDF-E/f4fdd410cdb84df81274da55721e56fb_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:e2d0a2efe40ce163ee9f88188a6ab51715bc121fdb08b20f48333613e0677dc8 +size 37737 diff --git a/marked/Y/T-REC-Y.2065-201403-I_PDF-E/5478f70a6cef3e5672b2b22d28830cfb_img.jpg b/marked/Y/T-REC-Y.2065-201403-I_PDF-E/5478f70a6cef3e5672b2b22d28830cfb_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..741aca7f97d5999de8775e5f4f8c961337f7d37c --- /dev/null +++ b/marked/Y/T-REC-Y.2065-201403-I_PDF-E/5478f70a6cef3e5672b2b22d28830cfb_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:08c349b418992255eceadcb33ff6645f71c1156c1494ff986e654cee021ba170 +size 60872 diff --git a/marked/Y/T-REC-Y.2065-201403-I_PDF-E/692541e65db4dc852988ce77ebb60ce5_img.jpg b/marked/Y/T-REC-Y.2065-201403-I_PDF-E/692541e65db4dc852988ce77ebb60ce5_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..3e876c259b056f077781106b173e8994136c20c7 --- /dev/null +++ b/marked/Y/T-REC-Y.2065-201403-I_PDF-E/692541e65db4dc852988ce77ebb60ce5_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:a58114124267d200e1d6f64f99a1e7a5fddd115dc3f501c3eaa3330fb7e81ec2 +size 58369 diff --git a/marked/Y/T-REC-Y.2065-201403-I_PDF-E/705ee99c3c44fd2a1ea6a3348ce8878f_img.jpg b/marked/Y/T-REC-Y.2065-201403-I_PDF-E/705ee99c3c44fd2a1ea6a3348ce8878f_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..5c9c9ce2fd0aa27194049c43fd1fd08279a46cbd --- /dev/null +++ b/marked/Y/T-REC-Y.2065-201403-I_PDF-E/705ee99c3c44fd2a1ea6a3348ce8878f_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:d6129b3bbd2020ef006d7f9b1154e5a751631938a97b36b2a22933e8ecf4c459 +size 61446 diff --git a/marked/Y/T-REC-Y.2065-201403-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg b/marked/Y/T-REC-Y.2065-201403-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..ddc2d86595291397b6e9e8f6cbafc0364c5f7181 --- /dev/null +++ b/marked/Y/T-REC-Y.2065-201403-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:bdd2ea26596b0a128c2e6f6216e4312884aa3acf2448cd3553f4604f94c06ead +size 6552 diff --git a/marked/Y/T-REC-Y.2065-201403-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg b/marked/Y/T-REC-Y.2065-201403-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..9dbf1b5b4811157ce1a874751db88bf7be9ffb3c --- /dev/null +++ b/marked/Y/T-REC-Y.2065-201403-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:62d508926e5d688741f59daf23a855864a6a5265413269e2c745de2ce471817a +size 34916 diff --git a/marked/Y/T-REC-Y.2065-201403-I_PDF-E/aaf3e6e44cdeabd6d1df869c5f392ea1_img.jpg b/marked/Y/T-REC-Y.2065-201403-I_PDF-E/aaf3e6e44cdeabd6d1df869c5f392ea1_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..1d914b5de2cb7d00ecd5c9341bf1a0dba0756f75 --- /dev/null +++ b/marked/Y/T-REC-Y.2065-201403-I_PDF-E/aaf3e6e44cdeabd6d1df869c5f392ea1_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:02948d458a18effe6cc0ed30c13dca3281d1ede345ab895c379d93a2beebef79 +size 82322 diff --git a/marked/Y/T-REC-Y.2065-201403-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg b/marked/Y/T-REC-Y.2065-201403-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..f2d6858715793df1b98cd7a7174c359a56dfcb47 --- /dev/null +++ b/marked/Y/T-REC-Y.2065-201403-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:6c751fc4b0551fab91033aef927ac2a9a8577ff4131d0feba64a0ef9bb37ce57 +size 28850 diff --git a/marked/Y/T-REC-Y.2065-201403-I_PDF-E/c85ded401105f62f2d6ff26b3b5eb4af_img.jpg b/marked/Y/T-REC-Y.2065-201403-I_PDF-E/c85ded401105f62f2d6ff26b3b5eb4af_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..9193f58324c617362f6e91ae5002b9ee46482422 --- /dev/null +++ b/marked/Y/T-REC-Y.2065-201403-I_PDF-E/c85ded401105f62f2d6ff26b3b5eb4af_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:012ad2d726c258fabc0cc1d0fd662438c208772f9cda99bc387483d69e67925a +size 61556 diff --git a/marked/Y/T-REC-Y.2065-201403-I_PDF-E/cbdfdade780e677eb1c1aef3081ce9ef_img.jpg b/marked/Y/T-REC-Y.2065-201403-I_PDF-E/cbdfdade780e677eb1c1aef3081ce9ef_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..ebf52f902ea795fe52e0cf17ca2e648ce1a39b10 --- /dev/null +++ b/marked/Y/T-REC-Y.2065-201403-I_PDF-E/cbdfdade780e677eb1c1aef3081ce9ef_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:54fcb82d6a0a0d990cfedf88c1e6b484a1ad79ca7945b95d546e91ba4ebc1b23 +size 46849 diff --git a/marked/Y/T-REC-Y.2065-201403-I_PDF-E/dc1f232cfd39be5c20b21374ad4c04c0_img.jpg b/marked/Y/T-REC-Y.2065-201403-I_PDF-E/dc1f232cfd39be5c20b21374ad4c04c0_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..8bbf59f01ad5f621231809da4eadc6a72c200e6a --- /dev/null +++ b/marked/Y/T-REC-Y.2065-201403-I_PDF-E/dc1f232cfd39be5c20b21374ad4c04c0_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:8e7a7749cf5cf2930034070a2908d022eb9a740024bae3797b2856ee5f68d783 +size 55306 diff --git a/marked/Y/T-REC-Y.2065-201403-I_PDF-E/ea4fd10a9a501c602f2bea0f7f711877_img.jpg b/marked/Y/T-REC-Y.2065-201403-I_PDF-E/ea4fd10a9a501c602f2bea0f7f711877_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..c30cfa90e444b6bf11cadd9c332cc44c5fcfb2f0 --- /dev/null +++ b/marked/Y/T-REC-Y.2065-201403-I_PDF-E/ea4fd10a9a501c602f2bea0f7f711877_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:971188c0bee3c1b88fe308f36344e7f4b32d606091891cbe5875d3edca22671d +size 47796 diff --git a/marked/Y/T-REC-Y.2065-201403-I_PDF-E/f9c64800d9bace9b4315646d1057be3c_img.jpg b/marked/Y/T-REC-Y.2065-201403-I_PDF-E/f9c64800d9bace9b4315646d1057be3c_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..2b900204204d75916e36c281e62418d00ce210be --- /dev/null +++ b/marked/Y/T-REC-Y.2065-201403-I_PDF-E/f9c64800d9bace9b4315646d1057be3c_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:4fac7c5d262bd087a909eb16b318cbd47cc58d6a4dbca653ec214921986d78a4 +size 51789 diff --git a/marked/Y/T-REC-Y.2084-201506-I_PDF-E/05eb72d372e4bf78e3d6a64949d77bcc_img.jpg b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/05eb72d372e4bf78e3d6a64949d77bcc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..57eaff8e8f10289ba7c14f9cc2c18df70a09f154 --- /dev/null +++ b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/05eb72d372e4bf78e3d6a64949d77bcc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:70666288dc68d7cf43f0b9b65601f815c3483215df541991f601987f74063741 +size 108650 diff --git a/marked/Y/T-REC-Y.2084-201506-I_PDF-E/14a22f23ced8ba1d63ece69861dbaacc_img.jpg b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/14a22f23ced8ba1d63ece69861dbaacc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..b251589cf40ace6dacc78699abda475ccc29cb4a --- /dev/null +++ b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/14a22f23ced8ba1d63ece69861dbaacc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:f5a5181407216d035f79590e56aec9a16d90fff38afd14731b2addf225d041a7 +size 4098 diff --git a/marked/Y/T-REC-Y.2084-201506-I_PDF-E/1a85642ed2356d183ce598f2c8b3ee8b_img.jpg b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/1a85642ed2356d183ce598f2c8b3ee8b_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..a9ef581c68fd95ee27195d0a768bdc68e509079b --- /dev/null +++ b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/1a85642ed2356d183ce598f2c8b3ee8b_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:7b8a80f812763998d1c44cdb782350f5d529b3f1d4a6a42d24f44b4030d9c309 +size 59619 diff --git a/marked/Y/T-REC-Y.2084-201506-I_PDF-E/21ad58fee90f2be50708ff541d225507_img.jpg b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/21ad58fee90f2be50708ff541d225507_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..229bc87e95b187399a01588cc342c00b43a898b7 --- /dev/null +++ b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/21ad58fee90f2be50708ff541d225507_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:3a3de2fb9b4b03a2a73a2b85e74d063f5794d5f51ec644c2b631670823bba6f6 +size 82424 diff --git a/marked/Y/T-REC-Y.2084-201506-I_PDF-E/366a77fdefb0097b3289b4a011911390_img.jpg b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/366a77fdefb0097b3289b4a011911390_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..37be8ecbfead5b1bbfcc5ca6263fb5c952ebd02f --- /dev/null +++ b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/366a77fdefb0097b3289b4a011911390_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:709c8b41d4c50c4e5d0c9db8174349f622ecf6edd838e9a45219008a8cc01b7d +size 140071 diff --git a/marked/Y/T-REC-Y.2084-201506-I_PDF-E/410562339ce067fdc6fa41940c118658_img.jpg b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/410562339ce067fdc6fa41940c118658_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..ccae90c2a233fea0bd7ce7b367e64d46dedc0b5b --- /dev/null +++ b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/410562339ce067fdc6fa41940c118658_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:e3c7e6d22c8e7e2ba1d4c99a9d11466975d78eb40716a4afdb768170af805731 +size 12576 diff --git a/marked/Y/T-REC-Y.2084-201506-I_PDF-E/4ee27dbf5ef12e7b58b0ef0937bc5a5e_img.jpg b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/4ee27dbf5ef12e7b58b0ef0937bc5a5e_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..e75e418ae48ceebec63489969ad79654eadcbbb1 --- /dev/null +++ b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/4ee27dbf5ef12e7b58b0ef0937bc5a5e_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:5f91606e658c233134f84966d468e5119a159aad75c8b521ce34518608d05eca +size 68317 diff --git a/marked/Y/T-REC-Y.2084-201506-I_PDF-E/724c7777b608e53be38b12b6fb3c43bc_img.jpg b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/724c7777b608e53be38b12b6fb3c43bc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..432eceabdec5eaefacf9ccb3ba8ce3e214a49f67 --- /dev/null +++ b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/724c7777b608e53be38b12b6fb3c43bc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:adbe3109596bf5ff6ac772dc3ec50da488e19b9604ac9e9bddfe935cb3a76f69 +size 61096 diff --git a/marked/Y/T-REC-Y.2084-201506-I_PDF-E/79e1709a7317ead45379cbb8ff3ba802_img.jpg b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/79e1709a7317ead45379cbb8ff3ba802_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..8bd11ea3bbf3d38f348a90aa7f85cfcf8233bfbb --- /dev/null +++ b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/79e1709a7317ead45379cbb8ff3ba802_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:bfcb2017fc9413245bd4603441b9e13b0836705a2bda8a9a6bd30039b62eb785 +size 113385 diff --git a/marked/Y/T-REC-Y.2084-201506-I_PDF-E/8c348bf9c2c81b018017ae1d19506a9a_img.jpg b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/8c348bf9c2c81b018017ae1d19506a9a_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..a9ae126c72a1ca5bf859fdfffba7ca58d2f9d249 --- /dev/null +++ b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/8c348bf9c2c81b018017ae1d19506a9a_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:5a9c632ff818b869cb7e54607695deaf0586f13f9d9424926fa802aad30ba9c4 +size 193819 diff --git a/marked/Y/T-REC-Y.2084-201506-I_PDF-E/aaec7c7044d764c324cdb35c0201da6f_img.jpg b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/aaec7c7044d764c324cdb35c0201da6f_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..8d19c27c02b49c925db732d60f3ecf4b6abc4653 --- /dev/null +++ b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/aaec7c7044d764c324cdb35c0201da6f_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:a239afb9029283f7b8ce70d1f5574c00bf36dfa3d2af9d4f22cdf110478e8889 +size 2681 diff --git a/marked/Y/T-REC-Y.2084-201506-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..fcb73e018e9d62e3433ddd52d7b23c3db7d4ed4e --- /dev/null +++ b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:50363244c682fab3615de6a173ef4970bc9f8ee3f55f86d3bfcf0c5625c1b19c +size 44014 diff --git a/marked/Y/T-REC-Y.2084-201506-I_PDF-E/b5335262987c819d7f71ce40f99cb71b_img.jpg b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/b5335262987c819d7f71ce40f99cb71b_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..be754c358bfcc016d3dd1443ce5bea68892b146c --- /dev/null +++ b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/b5335262987c819d7f71ce40f99cb71b_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:ef46c1a514eb1a2abe9860a7ec2d8dcfa0695c1868ae0d3b15e36f027ef3ed70 +size 109575 diff --git a/marked/Y/T-REC-Y.2084-201506-I_PDF-E/c494cd874a082a97b50b3c4d3938f467_img.jpg b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/c494cd874a082a97b50b3c4d3938f467_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..d5eefdcb1b49deb22b870fef44f2decd8ba4a874 --- /dev/null +++ b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/c494cd874a082a97b50b3c4d3938f467_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:2eab02b64bf1050ef088c12154702c166e34a118675bf258395d1546e6be7aef +size 201038 diff --git a/marked/Y/T-REC-Y.2084-201506-I_PDF-E/c914f51f4427bc672dd0526cfc90ebe9_img.jpg b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/c914f51f4427bc672dd0526cfc90ebe9_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..03315e881f519bf027382bc04584d8bd78fde95b --- /dev/null +++ b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/c914f51f4427bc672dd0526cfc90ebe9_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:6e9852cd4f0e2f608e26bde5d084fb3469f82ad58e24f4bd2e2d07217ac48fa8 +size 92341 diff --git a/marked/Y/T-REC-Y.2084-201506-I_PDF-E/cbdfdade780e677eb1c1aef3081ce9ef_img.jpg b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/cbdfdade780e677eb1c1aef3081ce9ef_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..219586611e3e528c6c2a0637ac5a339bd77c8eb3 --- /dev/null +++ b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/cbdfdade780e677eb1c1aef3081ce9ef_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:3fdb3c5603dded99689c160a0792db69ee96b7c70bc0b2587af46ef19183643a +size 125860 diff --git a/marked/Y/T-REC-Y.2084-201506-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..f4f0126a956f3371a58135bd095d7e71e54bba99 --- /dev/null +++ b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:fe6a0fd1865fe58ddaf83d5f6feebe784ab1250abf397250d43b7fa86a7084cf +size 19200 diff --git a/marked/Y/T-REC-Y.2084-201506-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..789af5853f99b0c6fb8cdd1dc4fd50d440b0af07 --- /dev/null +++ b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:76d797331cbe699c758dacacd0837128d425b0c2c15f026fe16a30ec392f56b4 +size 54996 diff --git a/marked/Y/T-REC-Y.2084-201506-I_PDF-E/fa859e4e468bfb2710a94527f2c504af_img.jpg b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/fa859e4e468bfb2710a94527f2c504af_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..68245992d615a525d68a004a76c1fe28be734b5d --- /dev/null +++ b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/fa859e4e468bfb2710a94527f2c504af_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:3d9da5f1fd97b05efa493fe07d7455e1eca1840f49475009bf95e146f2e3b733 +size 43639 diff --git a/marked/Y/T-REC-Y.2084-201506-I_PDF-E/raw.md b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..333041e1b9050343ae7c8c29cd4844cec232daf8 --- /dev/null +++ b/marked/Y/T-REC-Y.2084-201506-I_PDF-E/raw.md @@ -0,0 +1,1494 @@ + + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +# Y.2084 + +(06/2015) + +SERIES Y: GLOBAL INFORMATION +INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS +AND NEXT-GENERATION NETWORKS + +Next Generation Networks – Frameworks and functional +architecture models + +# --- **Distributed service networking content distribution functions** + +Recommendation ITU-T Y.2084 + +## ITU-T Y-SERIES RECOMMENDATIONS + +# GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS + +## GLOBAL INFORMATION INFRASTRUCTURE + +| | | +|-------------------------------------------|-------------| +| General | Y.100–Y.199 | +| Services, applications and middleware | Y.200–Y.299 | +| Network aspects | Y.300–Y.399 | +| Interfaces and protocols | Y.400–Y.499 | +| Numbering, addressing and naming | Y.500–Y.599 | +| Operation, administration and maintenance | Y.600–Y.699 | +| Security | Y.700–Y.799 | +| Performances | Y.800–Y.899 | + +## INTERNET PROTOCOL ASPECTS + +| | | +|--------------------------------------------------------------------|---------------| +| General | Y.1000–Y.1099 | +| Services and applications | Y.1100–Y.1199 | +| Architecture, access, network capabilities and resource management | Y.1200–Y.1299 | +| Transport | Y.1300–Y.1399 | +| Interworking | Y.1400–Y.1499 | +| Quality of service and network performance | Y.1500–Y.1599 | +| Signalling | Y.1600–Y.1699 | +| Operation, administration and maintenance | Y.1700–Y.1799 | +| Charging | Y.1800–Y.1899 | +| IPTV over NGN | Y.1900–Y.1999 | + +## NEXT GENERATION NETWORKS + +| | | +|-------------------------------------------------------------------|----------------------| +| Frameworks and functional architecture models | Y.2000–Y.2099 | +| Quality of Service and performance | Y.2100–Y.2199 | +| Service aspects: Service capabilities and service architecture | Y.2200–Y.2249 | +| Service aspects: Interoperability of services and networks in NGN | Y.2250–Y.2299 | +| Enhancements to NGN | Y.2300–Y.2399 | +| Network management | Y.2400–Y.2499 | +| Network control architectures and protocols | Y.2500–Y.2599 | +| Packet-based Networks | Y.2600–Y.2699 | +| Security | Y.2700–Y.2799 | +| Generalized mobility | Y.2800–Y.2899 | +| Carrier grade open environment | Y.2900–Y.2999 | + +## FUTURE NETWORKS + +| | | +|-----------------|---------------| +| CLOUD COMPUTING | Y.3500–Y.3999 | +|-----------------|---------------| + +*For further details, please refer to the list of ITU-T Recommendations.* + +## Recommendation ITU-T Y.2084 + +# Distributed service networking content distribution functions + +## Summary + +Recommendation ITU-T Y.2084 specifies the functions for distributed service networking (DSN) content distribution functions (CDFs), taking into account the requirements and capabilities for DSN as described in Recommendation ITU-T Y.2206 and the architecture for DSN as described in Recommendation ITU-T Y.2080. + +The main objective of this Recommendation is to provide guidance regarding the design of content-oriented services and applications making use of DSN CDF. + +## History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|----------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T Y.2084 | 2015-06-13 | 13 | 11.1002/1000/12511 | + +## Keywords + +CDF, content distribution function, distributed service networking, DSN, functional description, information flows, reference point. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. For example, . + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2015 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|---------------------------------------------------------------------------------------|-------------| +| 1 Scope..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 2 | +| 4 Abbreviation and acronyms..... | 2 | +| 5 Conventions ..... | 3 | +| 6 Functional description of DSN CDF ..... | 3 | +| 6.1 CDF functions ..... | 3 | +| 6.2 Reference points ..... | 4 | +| 6.3 Information flows ..... | 5 | +| 7 Security considerations..... | 10 | +| Appendix I – Detailed functional entity description of CDF ..... | 11 | +| I.1 Functional architecture of CDF ..... | 11 | +| I.2 Functional entities of CDF ..... | 12 | +| I.3 Reference points and interfaces..... | 13 | +| Appendix II – Use cases of DSN CDF and information flow for different scenarios ..... | 14 | +| II.1 Traditional cache ..... | 14 | +| II.2 Traditional CDN..... | 16 | +| II.3 P2P cache..... | 21 | +| II.4 P2P CDN ..... | 27 | +| II.5 Integration..... | 29 | +| Bibliography..... | 31 | + + + +# Recommendation ITU-T Y.2084 + +## Distributed service networking content distribution functions + +# 1 Scope + +This Recommendation specifies the distributed service networking (DSN) content distribution functions (CDFs) in detail, including: + +- the detail functions of DSN CDF; +- the description of reference points related to DSN CDF; +- the information flow related to DSN CDF. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- | | | +|----------------|-------------------------------------------------------------------------------------------------------------------| +| [ITU-T Y.1910] | Recommendation ITU-T Y.1910 (2008), IPTV functional architecture . | +| [ITU-T Y.2012] | Recommendation ITU-T Y.2012 (2010), Functional requirements and architecture of next generation networks . | +| [ITU-T Y.2019] | Recommendation ITU-T Y.2019 (2010), Content delivery functional architecture in NGN . | +| [ITU-T Y.2080] | Recommendation ITU-T Y.2080 (2012), Functional architecture for distributed service networking . | +| [ITU-T Y.2206] | Recommendation ITU-T Y.2206 (2010), Requirements for distributed service networking capabilities . | + +# 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 buffer map** [ITU-T Y.2080]: A map indicating the availability of chunks which can be shared with other DSN nodes. + +**3.1.2 chunk** [ITU-T Y.2080]: A basic unit of data resulting from partitioning a content file into defined component parts. A DSN node may use a chunk as a unit of storage, advertisement and exchange among peers. + +**3.1.3 content node** [b-ITU-T Y Suppl.10]: A DSN node which can be used for the media content distribution, storage and/or caching, etc. + +**3.1.4 distributed service networking** [ITU-T Y.2206]: An overlay network which provides distributed and manageable capabilities to support various multimedia services. + +**3.1.5 DSN node** [ITU-T Y.2206]: A node used in DSN providing distributed functionalities, including distributed routing and distributed storage. + +**3.1.6 functional entity** [ITU-T Y.2012]: An entity that comprises an indivisible set of specific functions. Functional entities are logical concepts, while groupings of functional entities are used to describe practical, physical implementations. + +**3.1.7 video on demand (VoD)** [ITU-T Y.1910]: A service in which the end user can, on demand, select and view video content and where the end user can control the temporal order in which the video content is viewed (e.g., the ability to start the viewing, pause, fast forward, rewind). + +### **3.2 Terms defined in this Recommendation** + +This Recommendation defines the following terms: + +**3.2.1 cache:** A device that has been set up to store content (e.g., web pages, files, videos and audios) that has been accessed by users on a network. A user trying to access content that has already been stored on the cache will be sent the stored version instead of downloading the content from the content source again. + +**3.2.2 content delivery network:** A content delivery network (CDN) is a system of distributed servers that deliver content (e.g., web pages, files, videos and audios) to users based on pre-defined criteria such as the geographic locations of users, the status of the content delivery server and the IP network connection. + +**3.2.3 live streaming:** A video service in which a continuous stream flows in real time from the service provider to the terminal device and the user cannot control the temporal order in which content is played. + +**3.2.4 P2P cache:** A computer or network device that has been set up to store peer-to-peer (P2P) content (e.g., file chunks, video chunks, audio chunks) that is popular and has been accessed by users. It works similar to cache. The only difference is that P2P cache supports P2P protocol and serves P2P content. Sometimes, cache and P2P cache could be co-located in the same device. + +**3.2.5 P2P CDN:** The content delivery network (CDN) in which content is delivered in the mode of P2P; the delivery may be from CDN server to users or from CDN servers to CDN servers. + +NOTE – Delivering in the mode of P2P means that the content is sliced into chunks, and the copies of the chunks are stored in multiple CDN servers. Users or CDN servers can download chunks of the content from multiple CDN servers. + +# **4 Abbreviation and acronyms** + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|--------|---------------------------------------------| +| CDF | Content Distribution Function | +| CDN | Content Delivery Network | +| CP | Content Provider | +| CP-FE | Content Processing Functional Entity | +| CSAF | Content Service Application Function | +| CS-FE | Cache/Storage Functional Entity | +| DBC-FE | Distribution Control Functional Entity | +| DD-FE | Distribution and Delivery Functional Entity | +| DLC-FE | Delivery Control Functional Entity | +| DSN | Distributed Service Networking | +| EF | End-user Function | + +| | | +|-------|---------------------------------------| +| ER-FE | Error Recovery Functional Entity | +| FE | Functional Entity | +| GSLB | Global Server Load Balancer | +| ISP | Internet Service Provider | +| MF | Management Function | +| P2P | Peer-to-Peer | +| RLF | Resource Location Function | +| SLB | Server Load Balancer | +| SP | Service Provider | +| TOCF | Traffic Optimization Control Function | +| UE | User Equipment | +| UGC | User Generated Content | +| URL | Uniform Resource Locator | +| VoD | Video on Demand | + +# 5 Conventions + +In this Recommendation the following conventions apply: + +- 1) The meaning of functions is as follows: + +**Functions:** In the context of DSN content distribution function, "Functions" are defined as a functional group composed of functional entities and is represented by the following symbol: + +![A diagram showing a rounded rectangular box, representing the symbol for a functional group.](aaec7c7044d764c324cdb35c0201da6f_img.jpg) + +A diagram showing a rounded rectangular box, representing the symbol for a functional group. + +- 2) DSN network means the network constructed based on DSN. + +# 6 Functional description of DSN CDF + +This clause describes the CDF functions, reference points related to CDF, and typical information flows. + +### 6.1 CDF functions + +CDF mainly performs the following functions: + +- 1) Content ingestion + - DSN CDF supports automatic and manual content ingestion from the content service application function (CSAF). +- 2) Content cache/store + - DSN CDF supports storing content in the form of chunks. + - DSN CDF supports time-to-live for stored content. + +NOTE 1 – Some content stored by CDF may be available only within a certain window of time. Providing a time-to-live value for stored data can reduce management overhead by avoiding "delete" commands sent to CDF storage. + +- DSN CDF supports deletion of stored content. + +NOTE 2 – A DSN node should be able to explicitly remove particular content (e.g., expired content). + +#### 3) Content processing + +- DSN CDF supports content chunking and reassembly of chunks. +- DSN CDF supports content pre-processing before content distribution. + +NOTE 3 – DSN CDF may perform content adaptation for different types of terminals and network environments. + +#### 4) Content transmission + +- DSN CDF enables the content to be transferred in the form of chunks. +- DSN CDF supports buffer map exchanges between other CDFs and end-user functions (EFs). +- DSN CDF supports content distribution between CDFs + +NOTE 4 – A DSN CDF can directly fetch data from other DSN CDFs. This helps to avoid additional transfers across Internet service provider (ISP) network links where possible. + +- DSN CDF support content distribution to EFs. + +NOTE 5 – DSN CDF supports centralized content distribution and distributed content distribution. Centralized content distribution means content is directly distributed from one specific DSN CDF, to all EFs, which require the content, without distributing to other DSN CDF nodes. Distributed content distribution means content is first distributed from one DSN CDF to other DSN CDFs located close to EFs, and is then distributed from these DSN CDFs to the requesting EFs. + +- DSN CDF supports content delivery control. The delivery control can be per-application, per-peer or per-data. + +NOTE 6 – An example for per-application control: one CDF node may run a video on demand (VoD) application and a live-streaming application simultaneously. The CDF node can control the delivery rate for different applications. + +NOTE 7 – An example for per-peer control: application policy may indicate that certain peers have higher bandwidth. The CDF node should be able to satisfy such requirements. + +NOTE 8 – An example for per-data control: application policy may indicate certain data is delivered with a higher priority. For example, chunks at the beginning part of a VoD content file are delivered at a higher rate so that the user can watch videos immediately when they are selected, while the chunks at the middle or rear part of the VoD content file is delivered at a lower rate, because there is enough time for the user to download the chunks. + +- DSN CDF provides integrity checks and error recovery in content delivery. +- DSN CDF supports negotiation of content delivery protocol between other CDFs and EFs. + +NOTE 9 – Because of particular application requirements and deployment considerations, different applications may support different protocols. DSN CDF is able to select an appropriate protocol. + +- DSN CDF performs content access control. + +NOTE 10 – A DSN CDF specifies access control policies for other DSN nodes (e.g., other CDF nodes, EF nodes). The authorized DSN nodes may read from or write to the DSN CDF. + +- DSN CDF maintains and reports the flow statistics information to the management function (MF) for accounting or contribution statistics. + +### 6.2 Reference points + +Figure 6-1 illustrates the reference points related to CDF. + +![Figure 6-1: Reference points related to CDF. The diagram shows four main components: RLF (Resource Location Function), CSAF (Content Service Access Function), CDFs (Content Delivery Functions), and EF (Edge Function). RLF and CSAF are on the left, connected to CDFs by dashed arrows labeled C3 and A5 respectively. CDFs is in the center, connected to EF on the right by a dashed arrow labeled C9. CDFs has a self-loop arrow labeled C10. The text 'CDFs Content delivery functions' is inside the CDFs box. The identifier 'Y.2084(15)_F6-1' is at the bottom right.](cfef993dcc8fb513de79eb1f93cf26ae_img.jpg) + +``` + +graph LR + RLF[RLF] <-->|C3| CDFs[CDFs +Content delivery functions] + CSAF[CSAF] <-->|A5| CDFs + CDFs <-->|C9| EF[EF] + CDFs -- C10 --> CDFs + +``` + +Figure 6-1: Reference points related to CDF. The diagram shows four main components: RLF (Resource Location Function), CSAF (Content Service Access Function), CDFs (Content Delivery Functions), and EF (Edge Function). RLF and CSAF are on the left, connected to CDFs by dashed arrows labeled C3 and A5 respectively. CDFs is in the center, connected to EF on the right by a dashed arrow labeled C9. CDFs has a self-loop arrow labeled C10. The text 'CDFs Content delivery functions' is inside the CDFs box. The identifier 'Y.2084(15)\_F6-1' is at the bottom right. + +**Figure 6-1 – Reference points related to CDF** + +#### 6.2.1 Reference point C3 + +The reference point C3 is between the CDF and the resource location function (RLF). + +This reference point is used by the CDF to: + +- register content to RLF; +- request RLF for content location information; +- report the status of a node in which CDF resides to RLF. The status information includes: CPU usage, memory usage, disk usage and network interface usage, etc.; +- report event related information to RLF, e.g., report that the load of the node in which CDF resides reached its threshold; +- report content related information to RLF, e.g., the content availability or content popularity, etc. + +#### 6.2.2 Reference point C9 + +The reference point C9 is between CDF and EF. + +This reference point is used by EF to: + +- query a buffer map from CDF; +- request content from CDF. + +#### 6.2.3 Reference point C10 + +The reference point C10 is between CDFs. + +This reference point is used by CDF to: + +- query a buffer map from another CDF; +- request content from another CDF. + +#### 6.2.4 Reference point A5 + +The reference point A5 is between the CDF and the CSAF. + +This reference point is used by CSAF to: + +- direct the CDF to process (e.g., transcoding, encryption) content. + +### 6.3 Information flows + +#### 6.3.1 Flow of content delivery from CDF to EF + +Figure 6-2 shows the flow of content delivery from CDF to EF. + +![Sequence diagram showing the flow of content delivery between EF, CSAF, RLF, and CDF. The steps are: 1. Content request (EF to CSAF), 2. Authentication (CSAF), 3. Content location request (CSAF to RLF), 4. Content location information (RLF to CSAF), 5. Content location information (CSAF to EF), 6. Content buffer map request (EF to CDF), 7. Content buffer map response (CDF to EF), 8. Content delivery request (EF to CDF), and 9. Contents delivery (CDF to EF).](d4af765160d04ecef538e5066006dc77_img.jpg) + +``` + +sequenceDiagram + participant EF + participant CSAF + participant RLF + participant CDF + + EF->>CSAF: 1. Content request + CSAF->>CSAF: 2. Authentication + CSAF->>RLF: 3. Content location request + RLF-->>CSAF: 4. Content location information + CSAF-->>EF: 5. Content location information + EF->>CDF: 6. Content buffer map request + CDF-->>EF: 7. Content buffer map response + EF->>CDF: 8. Content delivery request + CDF-->>EF: 9. Contents delivery + +``` + +Y.2084(15)\_F6-2 + +Sequence diagram showing the flow of content delivery between EF, CSAF, RLF, and CDF. The steps are: 1. Content request (EF to CSAF), 2. Authentication (CSAF), 3. Content location request (CSAF to RLF), 4. Content location information (RLF to CSAF), 5. Content location information (CSAF to EF), 6. Content buffer map request (EF to CDF), 7. Content buffer map response (CDF to EF), 8. Content delivery request (EF to CDF), and 9. Contents delivery (CDF to EF). + +**Figure 6-2 – Flow of content delivery** + +- 1) EF interacts with CSAF to request specified content with the content ID. +- 2) CSAF checks the authentication information of EF. +- 3) If the authentication succeeds, CSAF requests from RLF the location information of the content. +- 4) RLF sends the optimized location information of the content node(s) to CSAF. This information can be a peer list with the address of the content node(s). + +NOTE – For the details of RLF getting optimal content nodes, refer to clause I.2.2 in [ITU-T Y.2080]. + +- 5) CSAF forwards the content location information to EF. +- 6) EF chooses preferred content node(s) from the peer list, and interacts with CDF to request the buffer map of the content. +- 7) CDF returns the buffer map of the requested content to EF. +- 8) According to the buffer map, EF requests from CDF a certain chunk of the requested content. +- 9) CDF sends the requested content chunk to EF. + +#### 6.3.2 Flow of content registration + +Figure 6-3 shows the flow of content registration. This flow assumes that the user authentication has been finished. + +![Sequence diagram showing the flow of content registration between CP/SP, CSAF, CDF, and RLF.](af7916c89a458fdab6c3f443217388ae_img.jpg) + +``` + +sequenceDiagram + participant CP_SP as CP/SP + participant CSAF + participant CDF + participant RLF + + CP_SP->>CSAF: 1. Content and content metadata + CSAF->>CSAF: 2. Content pre-processing and metadata processing + CSAF->>CDF: 3. Content + CDF->>CDF: 4. Generate registration information + CDF->>RLF: 5. Content registration request + RLF-->>CDF: 6. Content registration response + +``` + +Y.2084(15)\_F6-3 + +Sequence diagram showing the flow of content registration between CP/SP, CSAF, CDF, and RLF. + +**Figure 6-3 – Flows of content registration** + +- 1) The content provider (CP) provides the content and metadata to CSAF. + - 2) CSAF handles the metadata processing and content pre-processing procedures. +- NOTE – The metadata processing includes the ID generation and the process of title, brief introduction, price, etc. The content pre-processing includes chunking, watermarking, advertising-inserting, format conversion, resolution conversion, etc. +- 3) CSAF ingests the content to CDF for further content distribution. + - 4) CDF generates the registration information, which includes the content ID and location of the content. + - 5) CDF initiates a content registration request to RLF. + - 6) RLF stores the registration information, and sends a response to inform CDF of the result. + +#### 6.3.3 Flow of buffer map requesting + +Figure 6-4 shows the flow of the CDF requesting a buffer map from another CDF. + +![Sequence diagram showing the flow of buffer map requesting between CDF A and CDF B.](410562339ce067fdc6fa41940c118658_img.jpg) + +``` + +sequenceDiagram + participant CDF_A as CDF A + participant CDF_B as CDF B + + CDF_A->>CDF_B: 1. Buffer map request + CDF_B-->>CDF_A: 2. Buffer map response + +``` + +Y.2084(15)\_F6-4 + +Sequence diagram showing the flow of buffer map requesting between CDF A and CDF B. + +**Figure 6-4 – Flow of CDF requesting buffer map from another CDF** + +- 1) CDF A sends a buffer map request to CDF B; the buffer map request contains the content ID. + - 2) CDF B returns the buffer map response to CDF A, indicating the content chunks it contains. +- NOTE – After retrieving the buffer map, CDF A can send a request to CDF B to download the selected content chunks. + +#### 6.3.4 Flow of content distribution between CDFs + +Figure 6-5 shows the procedures for content distribution between CDFs. This procedure applies when certain content is requested to be distributed from one CDF to another CDF. The CSAF initiates the content distribution from CDF 2 to CDF 1. + +![Sequence diagram showing the flow of content distribution between CSAF, RLF, CDF 1, and CDF 2.](4ee27dbf5ef12e7b58b0ef0937bc5a5e_img.jpg) + +``` +sequenceDiagram + participant CSAF + participant RLF + participant CDF1 as CDF 1 + participant CDF2 as CDF 2 + + CSAF->>RLF: 1. Content location request + Note over RLF: 2. Locate content + RLF->>CSAF: 3. Location of available content nodes + CSAF->>CDF1: 4. Content distribution request + CDF1->>CDF2: 5. Buffer map request + CDF2->>CDF1: 6. Buffer map response + CDF1->>CDF2: 7. Trunk request + CDF2->>CDF1: 8. Content transfer + Note over CDF1: 9. Content storage + CDF1->>RLF: 10. Content registration + Note over RLF: 11. Stores content location/meta-data + RLF->>CDF1: 12. Registration response + CDF1->>CSAF: 13. Content distribution response +``` + +Y.2084(15)\_F6-5 + +Sequence diagram showing the flow of content distribution between CSAF, RLF, CDF 1, and CDF 2. + +**Figure 6-5 – Flow of content distribution between CDFs** + +- 1) CSAF requests from RLF the location information of content needed to be distributed. +- 2) RLF locates the requested content. +- 3) RLF replies to CSAF with the location of available content nodes. + +NOTE – There may be more than one node; this flow takes CDF2 as an example. Other nodes follow the same procedure. + +- 4) CSAF requests CDF 1 to retrieve content from CDF 2. This request should contain the location information of CDF 2. +- 5) CDF 1 sends a buffer map request to CDF 2. The buffer map request contains the content ID. +- 6) CDF 2 returns the buffer map to CDF 1, indicating the content chunks it contains. +- 7) CDF 1 sends a request to CDF 2 to download the selected chunks. +- 8) The content is transferred from CDF 2 to CDF 1. +- 9) CDF 1 stores the received content. +- 10) When content delivery finishes, CDF 1 initiates a content registration request to RLF. The request message contains the content ID and the location of the content. +- 11) When RLF receives the content registration request, it stores the content location. +- 12) RLF sends a response to inform CDF 1 that content has been registered. +- 13) CDF 1 sends a response to inform CSAF that the content has been distributed to CDF 1. + +#### 6.3.5 Flow of content time-to-live management + +Figure 6-6 shows the procedures for content time-to-live management. This procedure applies for both content from the CP/service provider (SP) and the user generated content (UGC) content. + +![Sequence diagram showing the flow of content time-to-live management between CSAF, RLF, and CDF.](724c7777b608e53be38b12b6fb3c43bc_img.jpg) + +``` +sequenceDiagram + participant CSAF + participant RLF + participant CDF + Note over CSAF: 1. Content ingestion and registration + Note over CSAF: 2. Launch timer for this content + Note over CSAF: 3. Timer for a content expires + CSAF->>RLF: 4. Request for location of CDF + RLF-->>CSAF: 5. Location of CDF + CSAF->>CDF: 6. Request to delete content + Note over CDF: 7. Delete the content + CDF-->>RLF: 8. Confirm the deletion + Note over RLF: 9. Delete all the local information + RLF->>CDF: 10. RLF response + CDF-->>CSAF: 11. Confirm CSAF of the deletion +``` + +Y.2084(15)\_F6-6 + +Sequence diagram showing the flow of content time-to-live management between CSAF, RLF, and CDF. + +**Figure 6-6 – Flows of content time-to-live management** + +- 1) CSAF registers content to RLF as described in clause 6.3.2. +- 2) CSAF stores the time-to-live information and launches a timer for the specific content. +- 3) When the timer for this content expires, CSAF recognizes that it is time for this content to be deleted. +- 4) CSAF requests from RLF the CDF's location information for the expired content. +- 5) RLF returns the CDF's location information to CSAF. +- 6) CSAF requests all the related CDFs to delete the expired content. +- 7) CDF deletes the expired content. +- 8) When content is successfully deleted, CDF confirms the content deletion to RLF. +- 9) When RLF receives all CDF deletion confirmations, RLF deletes local information for this content. +- 10) RLF informs CDF of the deletion results. +- 11) CDF informs CSAF of the final content deletion. + +#### 6.3.6 Flow of content deletion + +Figure 6-7 shows the procedures for content deletion. This procedure applies for both content from the CP/SP and the UGC content. + +![Sequence diagram showing the flow of content deletion between CSAF, CDF, and RLF entities.](fa859e4e468bfb2710a94527f2c504af_img.jpg) + +``` + +sequenceDiagram + participant CSAF + participant CDF + participant RLF + + CSAF->>RLF: 1. Content location request + RLF-->>CSAF: 2. Content location response + CSAF->>CDF: 3. Request to delete content + Note over CDF: 4. Delete the content + CDF->>RLF: 5. Inform RLF the deletion + Note over RLF: 6. Delete the local information for this content + RLF-->>CDF: 7. RLF response + CDF-->>CSAF: 8. Inform CSAF the deletion + +``` + +Y.2084(15)\_F6-7 + +Sequence diagram showing the flow of content deletion between CSAF, CDF, and RLF entities. + +**Figure 6-7 – Flow of content deletion** + +- 1) CSAF requests from RLF the content location to be deleted. +- 2) RLF returns the location information to CSAF. +- 3) CSAF requests the CDF to delete the content. +- 4) CDF deletes the content. +- 5) CDF informs RLF of the deletion. +- 6) RLF deletes local information for this content. +- 7) RLF returns the deletion result to CDF. +- 8) CDF informs CSAF of the content deletion. + +# 7 Security considerations + +Security considerations are not addressed in this Recommendation. + +# Appendix I + +## Detailed functional entity description of CDF + +(This appendix does not form an integral part of this Recommendation.) + +As described in [ITU-T Y.2080], RLF is the function responsible for the optimized source selection and geographical content distribution. Compared to the CDF of NGN [ITU-T Y.2019], there is less functionality in the CDF of DSN, which is more focused on data transmission and delivery (e.g., cache/storage, content transcoding, encryption, accessing authorization, flow control), and the functions of content location and distribution are taken over by the RLF. When a DSN content service provider wants to set up a content service, upon DSN networks, it only needs to follow the reference points and information flow descriptions among CDF and other functions, but leaves the functions inside CDF to its own implementation. + +An illustration of the detailed functional entity (FE) description of CDF is given in this appendix only for better understanding of CDF functionalities. The functional architecture of DSN CDF references most parts of the definitions and descriptions from CDF of NGN [ITU-T Y.2019]. The major difference is that in DSN networks the content location and distribution are taken over by the RLF. + +### I.1 Functional architecture of CDF + +![Figure I.1 – CDF functional architecture diagram showing the interaction between RLF, CSAF, and the CDF functional entity groups.](21ad58fee90f2be50708ff541d225507_img.jpg) + +The diagram illustrates the functional architecture of the Content Delivery Function (CDF). It is divided into two main functional entity groups: the **Delivery control functional entity group** and the **Content delivery processing functional entity group**. + +**Delivery control functional entity group:** Contains the **DLC-FE (Delivery control FE)**. It has a self-loop labeled C10. It interfaces with the **RLF** (Reference Location Function) via interface C3-1 (outgoing) and C3-2 (incoming). It also interfaces with the **EF** (External Function) via interface C9-1 (outgoing) and C9-2 (incoming). + +**Content delivery processing functional entity group:** Contains four functional entities: **CS-FE (Cache/storage FE)**, **DD-FE (Distribution and delivery FE)**, **CP-FE (Content processing FE)**, and **ER-FE (Error recovery FE)**. These are interconnected via interfaces X1, X2, X3, and X4. Specifically, X1 connects DLC-FE to DD-FE, X2 connects DD-FE to ER-FE, X3 connects ER-FE to CP-FE, and X4 connects CP-FE to CS-FE. There is also a direct connection from DLC-FE to CS-FE. + +**External Functions:** The **RLF** and **CSAF** (Content Service Access Function) are external to the CDF. CSAF interfaces with the RLF via A5-1 (incoming) and A5-2 (outgoing). The RLF also has a direct interface to the CS-FE via C3-2. + +**Legend:** A dashed arrow with a double line indicates an "Interface in control plane". + +Y.2084(15)\_FI.1 + +Figure I.1 – CDF functional architecture diagram showing the interaction between RLF, CSAF, and the CDF functional entity groups. + +**Figure I.1 – CDF functional architecture** + +Figure I.1 describes the detailed CDF architecture with FEs; it is compatible with the CDF architecture. + +Further, each FE group includes several FEs: + +- The DLC FE group includes delivery control functional entity (DLC-FE); +- The content deliver processing (CDP) FE group includes cache/storage (CS), distribution and delivery (DD), error recovery (ER), and content processing functional entities. + +### **I.2 Functional entities of CDF** + +#### **I.2.1 Delivery control functional entity** + +The DLC-FE handles control functional entities related to the content delivery processing FE (CDP-FE) group. + +The DLC-FE supports content accessing authorization checks to the FEs, which belong to delivery processing FE groups. + +The DLC-FE is responsible for setting up sessions (e.g., content resource and media negotiation) for media content delivery. + +The DLC-FE manages the rate of transmission from the FEs, which belong to delivery processing FE groups, to recipients. + +The DLC-FE manages interaction with the EFs for service such as trick mode. + +The DLC-FE generates charging information based on traffic billing or content billing and reports it to CSAF. + +The DLC-FE generates a buffer map based on buffer status information received from the cache/storage functional entity (CS-FE). + +#### **I.2.2 Cache/storage functional entity** + +The CS-FE is responsible for caching or storing the content in order to support time-shifted stream-based services, as well as file-based services. + +The CS-FE reports its content and load status information to the distribution control functional entity (DBC-FE) in RLF. + +#### **I.2.3 Error recovery functional entity** + +The error recovery functional entity (ER-FE) serves to improve reliability in cases where network functions cannot provide sufficient quality of service (QoS). It generates additional information for a content stream, either proactively or on request, such that the recipients or senders, which have the error recovery functionality, can recover the content. + +The ER-FE relies on other CDF to deliver the additionally generated information. It also relies on the availability of EF. + +The ER-FE is selectively applied by forward error correction (FEC) or by retransmission. + +#### **I.2.4 Distribution and delivery functional entity** + +The distribution and delivery functional entity (DD-FE) is responsible for receiving the content from the CSAF and other FEs which belong to content delivery processing functional entity group, as well as distributing the content resource, which includes live streams or files, among the separate instances of FEs which belongs to content delivery processing functional entity group. + +The DD-FE is also responsible for delivering the content to the EF under the control of DBC-FE and DLC-FE. + +The DD-FE supports content retransmission potentially triggered by the ER-FE. + +The DD-FE executes the flow control policy made by the delivery control functional entity. + +The DD-FE selectively supports content tracing. + +#### **I.2.5 Content processing functional entity** + +The content processing functional entity (CP-FE) performs content processing under the control of the CSAF. The main functionalities are: + +- content transcoding; +- content encryption; +- other functionalities, such as: watermarking, advertising-insertion into streams, format conversion, resolution conversion, editing, etc. + +### **I.3 Reference points and interfaces** + +#### **I.3.1 Reference point X1** + +The reference point X1 is between the DLC-FE and the DD-FE. + +This reference point allows DLC-FE and DD-FE to interact for content accessing authorization. + +This reference point allows DLC-FE to control DD-FE to send the requested data to the end users. + +#### **I.3.2 Reference point X2** + +The reference point X2 is between the DD-FE and the ER-FE. + +This reference point is used for ER-FE to trigger content retransmission to DD-FE. + +#### **I.3.3 Reference point X3** + +The reference point X3 is between the CS-FE and the DD-FE. + +This reference point is used for CS-FE to store content to DD-FE. + +#### **I.3.4 Reference point X4** + +The reference point X4 is between the CS-FE and the DLC-FE. + +This reference point is used to request buffer status information from CS-FE and to give the buffer status information to DLC-FE. + +## Appendix II + +## Use cases of DSN CDF and information flow for different scenarios + +(This appendix does not form an integral part of this Recommendation.) + +This appendix illustrates how CDF is implemented in different scenarios such as: cache, content delivery network (CDN), peer-to-peer (P2P) cache and P2P CDF. + +NOTE – For the following use cases, RLF acts as different entities depending on the service. In P2P scenarios, RLF acts as a tracker for the streaming services, such as live streaming, VoD and file downloading. While in non-P2P scenarios, RLF acts as an entity similar to DNS for web browser service, and acts as a global server load balancer (GSLB)/server load balancer (SLB) for the streaming services. + +### II.1 Traditional cache + +#### II.1.1 Web browser + +Figure II.1 shows the flow for user equipment (UE) to access web browser service through cache. + +![Sequence diagram showing the flow of accessing web browsing service through traditional cache. The diagram involves four entities: EF (User Equipment), CDF (Content Delivery Function), MF (Management Function), and Web server. The flow is as follows: 1. EF sends a 'Content delivery request' to CDF. 2. CDF checks if the content is already stored and not expired. 3. If not stored, CDF sends a 'Content delivery request' to the Web server. 4. The Web server sends 'Contents delivery' to CDF. 5. CDF stores the content. 6. CDF sends 'Contents delivery' to EF. 7. CDF sends 'Flow statistic information' to MF. 8. MF stores/updates the flow statistic information.](1a85642ed2356d183ce598f2c8b3ee8b_img.jpg) + +``` +sequenceDiagram + participant EF + participant CDF + participant MF + participant Web_server as Web server + + EF->>CDF: 1. Content delivery request + Note over CDF: 2. Check if the content already stored and not expired + CDF-->>Web_server: 3. Content delivery request + Web_server-->>CDF: 4. Contents delivery + Note over CDF: 5. Store content + CDF-->>EF: 6. Contents delivery + CDF->>MF: 7. Flow statistic information + Note over MF: 8. Store/updates the flow statistic information +``` + +Sequence diagram showing the flow of accessing web browsing service through traditional cache. The diagram involves four entities: EF (User Equipment), CDF (Content Delivery Function), MF (Management Function), and Web server. The flow is as follows: 1. EF sends a 'Content delivery request' to CDF. 2. CDF checks if the content is already stored and not expired. 3. If not stored, CDF sends a 'Content delivery request' to the Web server. 4. The Web server sends 'Contents delivery' to CDF. 5. CDF stores the content. 6. CDF sends 'Contents delivery' to EF. 7. CDF sends 'Flow statistic information' to MF. 8. MF stores/updates the flow statistic information. + +Y.2084(15)\_FII.1 + +**Figure II.1 – Flow of accessing web browsing service through traditional cache** + +- 1) EF requests the URI resource from a web server; the CDF acts as cache and heads off the request. +- 2) CDF checks if the resource is already stored; if CDF has stored the valid resource, go directly to step 6. +- 3) If CDF has not stored the resource or the stored resource is expired, CDF requests the resource based on the requested URI from the real web server. +- 4) Web server will forward the requested resource to CDF. +- 5) CDF stores the resource temporarily for the next EF requesting the same resource. +- 6) CDF forwards the requested resource to the EF. +- 7) At this time, CDF treats this content delivery as finished, and sends the flow statistic information to MF. + +8) MF stores or updates the flow statistic information. + +#### II.1.2 Live streaming + +Figure II.2 shows the flow for a UE to access a live streaming service through traditional cache. + +![Sequence diagram showing the flow for a UE to access a live streaming service through traditional cache. The diagram involves five entities: EF, CSAF (portal), CDF, MF, and Content source. The flow consists of 18 steps: 1. Content service access request (EF to CSAF), 2. Reply with live content information (CSAF to EF), 3. Select content (EF local), 4. Content information request (EF to CSAF), 5. Authentication (CSAF local), 6. Content information (CSAF to EF), 7. Content delivery request (EF to CDF), 8. Check if the content already stored (CDF local), 9. Content delivery request (CDF to Content source), 10. Content delivery (Content source to CDF), 11. Store content (CDF local), 12. Contents delivery (CDF to EF), 13. Stop Watching (EF to CDF), 14. Flow statistic information (CDF to MF), 15. Store/Updates the flow statistic information (MF local), 16. Confirm close (CDF to EF), 17. Disconnect (EF to CSAF), 18. Disconnect OK (CSAF to EF). Steps 9-11 are enclosed in a dashed box labeled 'Option'.](79e1709a7317ead45379cbb8ff3ba802_img.jpg) + +``` +sequenceDiagram + participant EF + participant CSAF as CSAF (portal) + participant CDF + participant MF + participant ContentSource as Content source + + EF->>CSAF: 1. Content service access request + CSAF-->EF: 2. Reply with live content information + Note over EF: 3. Select content + EF->>CSAF: 4. Content information request + Note over CSAF: 5. Authentication + CSAF-->EF: 6. Content information + EF->>CDF: 7. Content delivery request + Note over CDF: 8. Check if the content already stored + CDF->>ContentSource: 9. Content delivery request + ContentSource-->CDF: 10. Content delivery + Note over CDF: 11. Store content + CDF-->EF: 12. Contents delivery + EF->>CDF: 13. Stop Watching + CDF->>MF: 14. Flow statistic information + Note over MF: 15. Store/Updates the flow statistic information + CDF-->EF: 16. Confirm close + EF->>CSAF: 17. Disconnect + CSAF-->EF: 18. Disconnect OK +``` + +Sequence diagram showing the flow for a UE to access a live streaming service through traditional cache. The diagram involves five entities: EF, CSAF (portal), CDF, MF, and Content source. The flow consists of 18 steps: 1. Content service access request (EF to CSAF), 2. Reply with live content information (CSAF to EF), 3. Select content (EF local), 4. Content information request (EF to CSAF), 5. Authentication (CSAF local), 6. Content information (CSAF to EF), 7. Content delivery request (EF to CDF), 8. Check if the content already stored (CDF local), 9. Content delivery request (CDF to Content source), 10. Content delivery (Content source to CDF), 11. Store content (CDF local), 12. Contents delivery (CDF to EF), 13. Stop Watching (EF to CDF), 14. Flow statistic information (CDF to MF), 15. Store/Updates the flow statistic information (MF local), 16. Confirm close (CDF to EF), 17. Disconnect (EF to CSAF), 18. Disconnect OK (CSAF to EF). Steps 9-11 are enclosed in a dashed box labeled 'Option'. + +Y.2084(15)\_FII.2 + +**Figure II.2 – Flow of accessing live streaming service through traditional cache** + +- 1) EF sends a content service access request to CSAF to get the live streaming service information (including the available channels, the price of the channels, the introduction of the channels, etc.). The ID and device type of the EF are included in the content service access request. The content service access request may also include the authentication information of the user. +- 2) CSAF replies EF with the information list of channels. EF may present the information to the user. + +NOTE – The information list contains the information related to the specific channel or video which CSAF needs to send to EF and it is used in the procedures of live streaming service and VoD service. The information + +list consists of two categories of information: 1) service information which includes the playback rate, resolution, audio and video codec, brief introduction and the payment information. 2) location information which includes identification and address information of CDFs which EF will request. + +- 3) EF selects the channel. +- 4) EF sends a content location request to CSAF to get the location information of the available content node. The content ID is included in the request. The request may also include the ID of the EF and authentication information. +- 5) CSAF checks the authentication information of EF. +- 6) If the authentication succeeds, CSAF forwards the content information to EF. +- 7) EF requests the content from the content source; the CDF acting as cache heads off the request. +- 8) CDF checks if the content is already stored; if CDF has stored the valid content, go directly to step 12. +- 9) If CDF has not stored the content, it requests the content from the content source. +- 10) Content source forwards the content to the CDF. +- 11) CDF stores the content temporarily for the next EF requesting the same content. +- 12) CDF forwards the content to the EF. +- 13) At the end of the viewing session, EF closes the streaming session. +- 14) When content delivery has finished, CDF sends the flow statistic information to MF. +- 15) MF stores or updates the flow statistic information. +- 16) CDF sends a confirm message to EF to confirm that the session is closed. +- 17) EF sends a disconnect message to CSAF to close the application session for this live streaming service. +- 18) CSAF confirms this close. + +#### **II.1.3 VoD and file downloading** + +The high-level sequence of flows for a UE to access VoD and file downloading service through traditional cache is similar to clause II.1.2 flows, except that the content type that EF requests is different. Refer to clause II.1.2 as this clause does not repeat the flows. + +### **II.2 Traditional CDN** + +#### **II.2.1 Web browser** + +Figure II.3 shows the flow for a UE to access web browsing service through traditional CDN. + +![Sequence diagram showing the flow of accessing web browsing service through traditional CDN. The diagram involves six entities: EF, RLF, TOCF, CDF, MF, and Web server. The process starts with '1. Contents pre-distribution' from Web server to CDF, followed by '2. Content registration' from CDF to RLF. Then '3. Content location request' from EF to RLF, leading to '4. Selecting optimized content node(s)' in RLF. This is followed by '5. Content location information' from RLF to EF, then '6. Content delivery request' from EF to CDF. CDF performs '7. Check if the content is expired'. If expired, '8. Redirection' occurs from CDF to EF. Then '9. Content delivery request' from EF to Web server, followed by '10. Contents delivery' from Web server to EF. If not expired, '11. Content delivery' occurs from CDF to EF. Finally, '12. Flow statistic information' is sent from CDF to MF, leading to '13. Store/Updates the flow statistic information' in MF.](c914f51f4427bc672dd0526cfc90ebe9_img.jpg) + +``` + +sequenceDiagram + participant EF + participant RLF + participant TOCF + participant CDF + participant MF + participant Web_server as Web server + + Web_server->>CDF: 1. Contents pre-distribution + CDF->>RLF: 2. Content registration + EF->>RLF: 3. Content location request + RLF->>RLF: 4. Selecting optimized content node(s) + RLF->>EF: 5. Content location information + EF->>CDF: 6. Content delivery request + CDF->>CDF: 7. Check if the content is expired + CDF->>EF: 8. Redirection + EF->>Web_server: 9. Content delivery request + Web_server->>EF: 10. Contents delivery + CDF->>EF: 11. Content delivery + CDF->>MF: 12. Flow statistic information + MF->>MF: 13. Store/Updates the flow statistic information + +``` + +Sequence diagram showing the flow of accessing web browsing service through traditional CDN. The diagram involves six entities: EF, RLF, TOCF, CDF, MF, and Web server. The process starts with '1. Contents pre-distribution' from Web server to CDF, followed by '2. Content registration' from CDF to RLF. Then '3. Content location request' from EF to RLF, leading to '4. Selecting optimized content node(s)' in RLF. This is followed by '5. Content location information' from RLF to EF, then '6. Content delivery request' from EF to CDF. CDF performs '7. Check if the content is expired'. If expired, '8. Redirection' occurs from CDF to EF. Then '9. Content delivery request' from EF to Web server, followed by '10. Contents delivery' from Web server to EF. If not expired, '11. Content delivery' occurs from CDF to EF. Finally, '12. Flow statistic information' is sent from CDF to MF, leading to '13. Store/Updates the flow statistic information' in MF. + +Y.2084(15)\_FII.3 + +**Figure II.3 – Flow of accessing web browsing service through traditional CDN** + +1) Web server pre-distributes the resource to CDF. + +2) CDF registers the content to RLF. + +NOTE – Refer to clause 6.3.2 for the flow of content registration. + +3) EF sends a content location request to RLF to get the location information of available content nodes. The request URI is included in the request. The request may also include the ID of the EF and authentication information. + +4) RLF interacts with traffic optimization control function (TOCF) to request optimized location information. RLF selects the optimal content nodes based on the information from TOCF. + +5) RLF sends the optimized location information of the content nodes to EF. + +6) EF requests the content from the CDF. + +7) CDF checks whether the resource is expired; if CDF has stored the valid resource, go directly to step 11. + +8) If CDF has not stored the resource or the resource stored is expired, CDF responds to EF with redirection to the requested URI from the source web server. + +9) EF requests the original content from the source web server. + +10) The web server forwards the requested resource to EF. + +11) If CDF has stored the resource, CDF forwards the requested resource to EF. + +12) Content delivery finishes, and then CDF sends the flow statistic information to MF. + +13) MF stores or updates the flow statistic information. + +#### II.2.2 Live streaming + +Figure II.4 shows the flow for a UE to access live streaming service through traditional CDN. + +![Sequence diagram showing the flow of accessing live streaming service through traditional CDN. The diagram involves seven entities: EF, CSAF, RLF, TOCF, CDF, MF, and Web server. The process starts with the Web server pre-distributing content to the CDF (Step 1). The CDF registers the content with the RLF (Step 2). The EF sends a content service access request to the CSAF (Step 3), which replies with live content information (Step 4). The EF selects content (Step 5) and requests content information from the CSAF (Step 6). The CSAF performs authentication (Step 7) and requests content location from the RLF (Step 8). The RLF selects optimized content node(s) (Step 9) and provides content location information to the CSAF (Step 10). The CSAF provides content location information to the EF (Step 11). The EF joins a unicast/multicast group (Step 12) and the CDF prepares resources for the EF (Step 13). Content delivery begins (Step 14). The EF stops watching (Step 15) and the CDF releases resources for the EF (Step 16). The CDF sends flow statistic information to the MF (Step 17), which stores or updates the information (Step 18). The EF confirms close (Step 19) and disconnects (Step 20), with the CSAF responding with 'Disconnect OK' (Step 21).](366a77fdefb0097b3289b4a011911390_img.jpg) + +``` + +sequenceDiagram + participant EF + participant CSAF + participant RLF + participant TOCF + participant CDF + participant MF + participant Web_server as Web server + + Web_server->>CDF: 1. Contents pre-distribute + CDF->>RLF: 2. Content registration + EF->>CSAF: 3. Content service access request + CSAF->>EF: 4. Reply with live content information + EF->>EF: 5. Select content + EF->>CSAF: 6. Content information request + CSAF->>CSAF: 7. Authentication + CSAF->>RLF: 8. Content location request + RLF->>RLF: 9. Selecting optimized content node(s) + RLF->>CSAF: 10. Content location information + CSAF->>EF: 11. Content location information + EF->>CDF: 12. Join a unicast/multicast group + CDF->>CDF: 13. Prepare resources for EF + CDF->>EF: 14. Contents delivery + EF->>CDF: 15. Stop watching + CDF->>CDF: 16. Release resources for EF + CDF->>MF: 17. Flow statistic information + MF->>MF: 18. Store/Updates the flow statistic information + EF->>CDF: 19. Confirm close + EF->>CSAF: 20. Disconnect + CSAF->>EF: 21. Disconnect OK + +``` + +Sequence diagram showing the flow of accessing live streaming service through traditional CDN. The diagram involves seven entities: EF, CSAF, RLF, TOCF, CDF, MF, and Web server. The process starts with the Web server pre-distributing content to the CDF (Step 1). The CDF registers the content with the RLF (Step 2). The EF sends a content service access request to the CSAF (Step 3), which replies with live content information (Step 4). The EF selects content (Step 5) and requests content information from the CSAF (Step 6). The CSAF performs authentication (Step 7) and requests content location from the RLF (Step 8). The RLF selects optimized content node(s) (Step 9) and provides content location information to the CSAF (Step 10). The CSAF provides content location information to the EF (Step 11). The EF joins a unicast/multicast group (Step 12) and the CDF prepares resources for the EF (Step 13). Content delivery begins (Step 14). The EF stops watching (Step 15) and the CDF releases resources for the EF (Step 16). The CDF sends flow statistic information to the MF (Step 17), which stores or updates the information (Step 18). The EF confirms close (Step 19) and disconnects (Step 20), with the CSAF responding with 'Disconnect OK' (Step 21). + +Y.2084(15)\_FII.4 + +**Figure II.4 – Flow of accessing live streaming service through traditional CDN** + +- 1) Web server pre-distributes the resource to other CDF(s). +- 2) CDF contacts RLF to register the content received. +- 3) EF sends a content service access request to CSAF to get the live streaming service information (including the available channels, the price of the channels, the introduction of the channels, etc.). The ID and device type of the EF are included in the content service access request. The content service access request may also include the authentication information of the user. + +- 4) CSAF replies to EF with the information list of channels. EF may present the information to the user. +- 5) EF selects the channel. +- 6) EF sends a content location request to CSAF to get the location information of available content nodes. The content ID is included in the request. The request may also include the ID of the EF and authentication information. +- 7) CSAF checks the authentication information of EF. +- 8) If the authentication succeeded, CSAF requests the location information of the content from RLF. +- 9) RLF interacts with TOCF to request optimized location information. RLF selects optimal content nodes based on the information from TOCF. +- 10) RLF sends the optimized location information of the content nodes to the CSAF. The information can be a peer list with the address of the content nodes. +- 11) CSAF forwards the content location information to EF. +- 12) EF chooses preferred content node(s) from the peer list, and interacts with the CDF to join the unicast/multicast group for receive content of the channel. +- 13) When the request is received, CDF prepares resources for serving the EF. +- 14) When CDF is ready, CDF delivers the content of the channel to the requesting EF. +- 15) At the end of the viewing session, EF closes the streaming session. +- 16) CDF releases the resource related to the EF. +- 17) Content delivery finishes and CDF sends the flow statistic information to MF. +- 18) MF stores or updates the flow statistic information. +- 19) CDF sends a confirm message to EF to confirm that the session is closed. +- 20) EF sends a disconnect message to CSAF to close the application session for this live streaming service. +- 21) CSAF confirms the close. + +#### **II.2.3 VoD** + +Figure II.5 shows the flow for a UE to access VoD service through traditional CDN. + +![Sequence diagram showing the flows of accessing VoD service through traditional CDN. The diagram involves seven entities: EF, CSAF, RLF, TOCF, CDF, MF, and Content source. The process starts with content pre-distribution from the Content source to CDF, followed by registration with RLF. The EF then requests service from CSAF, selects a video, and requests location information from CSAF. After authentication, CSAF requests location info from RLF, which selects optimized nodes. CSAF then delivers content to CDF, and the EF stops watching. Finally, resources are released for EF, flow statistics are updated, and the connection is closed.](cbdfdade780e677eb1c1aef3081ce9ef_img.jpg) + +``` + +sequenceDiagram + participant EF + participant CSAF + participant RLF + participant TOCF + participant CDF + participant MF + participant ContentSource as Content source + + ContentSource->>CDF: 1. Contents pre-distribute + CDF->>RLF: 2. Content registration + EF->>CSAF: 3. Content service access request + CSAF->>EF: 4. Reply with video content information + EF->>EF: 5. Select video + EF->>CSAF: 6. Content information request + CSAF->>CSAF: 7. Authentication + CSAF->>RLF: 8. Content location request + RLF->>RLF: 9. Selecting optimized content node(s) + RLF->>CSAF: 10. Content location information + CSAF->>EF: 11. Content location information + EF->>CDF: 12. Content delivery request + CDF->>EF: 13. Contents delivery + EF->>CDF: 14. Stop watching + CDF->>CDF: 15. Release resources for EF + CDF->>MF: 16. Flow statistic information + MF->>MF: 17. Store/Updates the flow statistic information + CDF->>EF: 18. Confirm close + EF->>CSAF: 19. Disconnect + CSAF->>EF: 20. Disconnect OK + +``` + +Sequence diagram showing the flows of accessing VoD service through traditional CDN. The diagram involves seven entities: EF, CSAF, RLF, TOCF, CDF, MF, and Content source. The process starts with content pre-distribution from the Content source to CDF, followed by registration with RLF. The EF then requests service from CSAF, selects a video, and requests location information from CSAF. After authentication, CSAF requests location info from RLF, which selects optimized nodes. CSAF then delivers content to CDF, and the EF stops watching. Finally, resources are released for EF, flow statistics are updated, and the connection is closed. + +Y.2084(15)\_F11.5 + +**Figure II.5 – Flows of accessing VoD service through traditional CDN** + +- 1) Content source pre-distributes the resource to other CDF(s). +- 2) CDF contacts RLF to register the content received. +- 3) EF sends a content service access request to CSAF to get the VoD service information (including the available videos, the price of the videos, the introduction of the videos, etc.). The ID and device type of the EF are included in the content service access request. The content service access request may also include the authentication information of the user. +- 4) CSAF replies to EF with the information list of videos. EF may present this information to the user. +- 5) EF selects the video. +- 6) EF sends a content location request to CSAF to get the location information of available content nodes. The content ID is included in the request. The request may also include the ID of the EF and authentication information. +- 7) CSAF checks the authentication information of EF. + +- 8) If the authentication succeeds, CSAF requests the location information of the content from RLF. +- 9) RLF interacts with TOCF to request optimized location information. RLF selects optimal content nodes based on the information from TOCF. +- 10) RLF sends the optimized location information of the content nodes to the CSAF. The information can be a peer list with the address of the content nodes. +- 11) CSAF forwards the content location information to EF. +- 12) EF chooses a preferred content node from the peer list, and requests a certain chunk of this content from CDF. +- 13) CDF sends the requested chunk to EF. +- 14) At the end of the viewing session, the EF closes the streaming session. +- 15) CDF releases the resource related to the EF. +- 16) Content delivery finishes and CDF sends the flow statistic information to MF. +- 17) MF stores or updates the flow statistic information. +- 18) CDF sends a confirm message to EF to confirm that the session is closed. +- 19) EF sends a disconnect message to CSAF to close the application session for this VOD service. +- 20) CSAF confirms this close. + +#### **II.2.4 File downloading** + +The flow for a UE to access file downloading service through traditional CDN is similar clause II.2.3 flow except the content type EF requests are different. Refer to clause II.2.3 as this clause does not repeat the flows. + +### **II.3 P2P cache** + +#### **II.3.1 Live streaming** + +The flow for P2P cache live streaming is shown in Figure II.6. In this case, different EFs joining the same live stream will always request the same content. The first content request from the EF is forwarded by CDF to remote nodes possessing the content. A remote node could be either a remote CDF, which has already cached the content, or a remote peer, which provides the original content. + +![Sequence diagram showing the flow of accessing live streaming service through P2P cache between EF, CSAF, RLF, TOCF, CDF, MF, and Remote node. The diagram includes two options for content delivery and flow statistics.](8c348bf9c2c81b018017ae1d19506a9a_img.jpg) + +``` + +sequenceDiagram + participant EF + participant CSAF + participant RLF + participant TOCF + participant CDF + participant MF + participant RemoteNode as Remote node + + EF->>CSAF: 1. Content information request + activate CSAF + CSAF->>CSAF: 2. Authentication + deactivate CSAF + CSAF->>RLF: 3. Content location request + activate RLF + RLF->>RLF: 4. Selecting optimized content nodes + deactivate RLF + RLF->>CSAF: 5. Content location information + deactivate RLF + CSAF->>EF: 6. Content location information + deactivate CSAF + + Note over EF, CSAF, RLF, TOCF, CDF, MF, RemoteNode: Option 1 + EF->>CDF: 7. Content buffer map request + activate CDF + CDF->>EF: 8. Content buffer map response + deactivate CDF + EF->>CDF: 9. Content delivery request + activate CDF + CDF->>EF: 10. Content delivery + deactivate CDF + CDF->>CDF: 11. Content storage + deactivate CDF + CDF->>RLF: 12. Content registration + activate RLF + RLF->>EF: 13. Stop watching + deactivate RLF + CDF->>MF: 14. Flow statistic information + activate MF + MF->>MF: 15. Store/Updates the flow statistic information + deactivate MF + CDF->>EF: 16. Confirm close + deactivate CDF + + Note over EF, CSAF, RLF, TOCF, CDF, MF, RemoteNode: Option 2 + EF->>CDF: 7. Content buffer map request + activate CDF + CDF->>EF: 8. Content buffer map response + deactivate CDF + EF->>CDF: 9. Content delivery request + activate CDF + CDF->>EF: 10. Content delivery + deactivate CDF + EF->>CDF: 11. Stop watching + deactivate EF + CDF->>MF: 12. Flow statistic information + activate MF + MF->>MF: 13. Store/Updates the flow statistic information + deactivate MF + CDF->>EF: 14. Confirm close + deactivate CDF + + EF->>CSAF: 17/15. Disconnect + activate CSAF + CSAF->>EF: 18/16. Disconnect OK + deactivate CSAF + +``` + +Sequence diagram showing the flow of accessing live streaming service through P2P cache between EF, CSAF, RLF, TOCF, CDF, MF, and Remote node. The diagram includes two options for content delivery and flow statistics. + +Y.2084(15)\_F11.6 + +**Figure II.6 – Flow of accessing live streaming service through P2P cache** + +- 1) EF sends CSAF a live content request. It sends a content information request to CSAF to get the location information of available content nodes. The content ID is included in the request. The request may also include the ID of the EF and authentication information. +- 2) CSAF checks the authentication information of EF. + +- 3) If the authentication succeeds, CSAF requests the location information of the content from RLF. +- 4) RLF interacts with TOCF to request optimized location information. RLF selects optimal content nodes based on the information from TOCF. +- 5) RLF sends the optimized location information of the content nodes to the CSAF. The information can be a peer list with the address of the content nodes. +- 6) CSAF forwards the peer list information to EF. If there is no content stored in CDF, CSAF forwards the remote peer list information to EF. If CDF has stored the current content, CSAF forwards the information of CDF to EF. + +##### **Option 1:** Current content is not yet stored in CDF. + +- 7) EF chooses a group of preferred peers (e.g., content nodes, UEs or remote CDFs that have cached the content and are located near the UE) from the peer list and interacts with those peers to request the buffer map of the content. These requests are transparently redirected to the CDF, which passes these requests on to a remote P2P user. +- 8) The remote P2P user sends the content buffer map information back to EF, similar to step 7; the response is transparently intercepted by CDF. +- 9) EF requests the remote node to deliver the content, similar to step 7; the request is redirected to CDF and then be passed on to the remote node. +- 10) The remote node, which has the content, sends the content data back to EF, similar to step 8; the content data is intercepted by CDF. +- 11) CDF stores the content for the next EFs. +- 12) CDF registers the content to RLF. +- 13) EF sends a request to the remote node to stop watching the live content, similar to step 7; the request is redirected to CDF and then be passed on to the remote node. +- 14) CDF discovers that the remote node stops to deliver the content. It sends flow statistic information to MF. +- 15) MF stores or updates the flow statistic information. +- 16) The remote node sends a confirm message to EF to confirm that the session is closed. +- 17) EF sends a disconnect message to CSAF to close the application session for this live steaming service. +- 18) CSAF confirms this close. + +##### **Option 2:** Current content is stored in CDF. The peer list obtained from CSAF includes the address of CDF as a peer serving the content for EF. + +- 7) EF sends a request for the content buffer map to CDF. +- 8) CDF returns the content buffer map information to EF. +- 9) EF requests CDF to deliver the content. +- 10) CDF delivers the stored content to EF. +- 11) When EF stops watching the content, it sends a request to CDF. +- 12) CDF stops the content delivery and sends flow statistic information to MF. +- 13) MF stores or updates the flow statistic information. +- 14) CDF sends a confirm message to EF to confirm that the session is closed. +- 15) EF sends a disconnect message to CSAF to close the application session for this live steaming service. +- 16) CSAF confirms this close. + +NOTE – EF may interact with multiple remote nodes at the same time. + +#### **II.3.2 VoD and file downloading** + +The flow for P2P cache VoD usage is shown in Figure II.7. + +In this case, different EFs may request different VoD/file contents or different parts of the same VoD/file content. + +NOTE 1 – VoD content must be constantly received by EFs and presented to an end user. File downloading does not require continuity. It does not matter which part of the file content is received first. File downloading will be successfully finished as long as all the parts of the file content are received, regardless of the receiving sequence. End users served by these two services should have different strategies in request sending and jitter buffering. + +NOTE 2 – EF may interact with multiple remote nodes at the same time; this flow illustration only uses one. + +![Sequence diagram showing the flow of accessing VoD and file downloading service through P2P cache between EF, CSAF, RLF, TOCF, CDF, MF, and Remote node. The diagram is divided into Option 1 and Option 2 paths.](c494cd874a082a97b50b3c4d3938f467_img.jpg) + +``` + +sequenceDiagram + participant EF + participant CSAF + participant RLF + participant TOCF + participant CDF + participant MF + participant RemoteNode as Remote node + + EF->>CSAF: 1. Chunk n information request + activate CSAF + CSAF->>CSAF: 2. Authentication + deactivate CSAF + CSAF->>RLF: 3. Content location request + activate RLF + RLF->>RLF: 4. Selecting optimized content nodes + deactivate RLF + RLF->>CSAF: 5. Content location information + deactivate RLF + CSAF->>EF: 6. Content location information + deactivate CSAF + + %% Option 1 + EF->>CDF: 7. Content buffer map request + activate CDF + CDF->>EF: 8. Content buffer map response + deactivate CDF + EF->>CDF: 9. Chunk n delivery request + activate CDF + CDF->>EF: 10. Chunk n delivery + deactivate CDF + EF->>CDF: 11. Chunk n storage + activate CDF + CDF->>RLF: 12. Chunk n registration + deactivate CDF + RLF->>CDF: 13. Stop delivering + deactivate RLF + CDF->>MF: 14. Flow statistic information + activate MF + MF->>MF: 15. Store/Updates the flow statistic information + deactivate MF + CDF->>EF: 16. Confirm close + deactivate CDF + + %% Option 2 + EF->>CDF: 7. Content buffer map request + activate CDF + CDF->>EF: 8. Content buffer map response + deactivate CDF + EF->>CDF: 9. Chunk n delivery request + activate CDF + CDF->>EF: 10. Chunk n delivery + deactivate CDF + EF->>CDF: 11. Stop delivering + deactivate EF + CDF->>MF: 12. Flow statistic information + activate MF + MF->>MF: 13. Store/Updates the flow statistic information + deactivate MF + CDF->>EF: 14. Confirm close + deactivate CDF + + EF->>CSAF: 17/15. Disconnect + activate CSAF + CSAF->>EF: 18/16. Disconnect OK + deactivate CSAF + +``` + +The diagram illustrates the flow of accessing VoD and file downloading service through P2P cache. It involves seven entities: EF (End User), CSAF (Content Selection and Authentication Function), RLF (Remote Location Function), TOCF (Topology Control Function), CDF (Content Delivery Function), MF (Management Function), and Remote node. The process is divided into two main options, Option 1 and Option 2, which are enclosed in dashed boxes. Option 1 includes steps 7 through 16, while Option 2 includes steps 7 through 14. Both options start with a 'Chunk n information request' from EF to CSAF, followed by authentication and content location requests. Option 1 involves a 'Chunk n storage' step and a 'Flow statistic information' step, while Option 2 involves a 'Flow statistic information' step. Both options end with a 'Disconnect' message from EF to CSAF and a 'Disconnect OK' response from CSAF to EF. + +Sequence diagram showing the flow of accessing VoD and file downloading service through P2P cache between EF, CSAF, RLF, TOCF, CDF, MF, and Remote node. The diagram is divided into Option 1 and Option 2 paths. + +Y.2084(15)\_F11.7 + +**Figure II.7 – Flow of accessing VoD and file downloading service through P2P cache** + +- 1) EF is in a streaming/file downloading process. It sends a content information request to CSAF to get the location information of available content nodes. The content ID is included in the request. The request may also include the ID of the EF and authentication information. +- 2) CSAF checks the authentication information of EF. + +- 3) If the authentication succeeds, CSAF requests the location information of the content from RLF. +- 4) RLF interacts with TOCF to request optimized location information. RLF selects optimal content nodes based on the information from TOCF. +- 5) RLF sends the optimized location information of the content nodes to the CSAF. The information can be a peer list with the address of the content nodes. +- 6) CSAF forwards the peer list information to EF. If there is no content stored in CDF, CSAF will forward the peer list information to EF. If CDF has stored the current content, CSAF will forward the information of CDF to EF. + +**Option 1:** Chunk n is not yet stored in CDF. + +- 7) EF chooses a group of preferred peers (both content nodes and UEs) from the peer list, and interacts with these peers to request the buffer map of the content. These requests will be transparently redirected to the CDF, which will pass these requests on to a remote P2P user. +- 8) The remote P2P user sends the content buffer map information back to EF, similar to step 7, the response will be transparently intercepted by CDF. +- 9) EF requests the remote node to deliver chunk n of the content, similar to step 7, the request will be redirected to CDF and will then be passed on to the remote node. +- 10) The remote node, which has the content, sends chunk n of the content data back to EF, similar to step 8, the content data will be intercepted by CDF. +- 11) CDF stores chunk n for the next EFs. +- 12) CDF registers chunk n to RLF. +- 13) EF sends a request to the remote node to stop streaming the current content, similar to step 7, the request will be redirected to CDF and will then be passed on to the remote node. +- 14) CDF finds out that the remote node stops delivering the content. It sends flow statistic information to MF. +- 15) MF stores or updates the flow statistic information. +- 16) The remote node sends a confirm message to EF to confirm that the session is closed. +- 17) EF sends a disconnect message to CSAF to close the application session for this VoD/file downloading service. +- 18) CSAF confirms this close. + +**Option 2:** Chunk n is stored in CDF. The peer list obtained from CSAF includes the address of CDF as a peer serving the content for EF. + +- 7) EF requests the buffer map from CDF. +- 8) CDF returns the buffer map to EF. +- 9) EF requests CDF to deliver chunk n. +- 10) CDF sends its stored chunk n to EF. +- 11) If EF finishes or interrupts the streaming of the content, it sends a request to CDF to stop delivering the content. +- 12) CDF sends flow statistic information to MF. +- 13) MF stores or updates the flow statistic information. +- 14) CDF sends a confirm message to EF to confirm that the session is closed. +- 15) EF sends a disconnect message to CSAF to close the application session for this VoD/file downloading service. +- 16) CSAF confirms this close. + +### II.4 P2P CDN + +#### II.4.1 Live streaming + +Figure II.8 shows the flow for a UE to access live streaming service through CDN with P2P model. + +![Sequence diagram showing the flow of accessing live streaming service through P2P CDN. The diagram involves six entities: EF, CSAF, RLF, TOCF, CDF, and Remote node. The flow consists of 15 steps: 1. Contents pre-distribution (Remote node to CDF), 2. Content registration (CDF to RLF), 3. Content service access request (EF to CSAF), 4. Authentication (CSAF to EF), 5. Reply with live content information (CSAF to EF), 6. Select content (EF), 7. Content information request (EF to CSAF), 8. Content location request (CSAF to RLF), 9. Selecting optimized content node(s) (RLF), 10. Content location information (RLF to CSAF), 11. Content location information (CSAF to EF), 12. Content buffer map request (EF to CDF), 13. Content buffer map response (CDF to EF), 14. Content delivery request (EF to CDF), 15. Contents delivery (CDF to EF). A note indicates that EF interacts with a series of CDFs at the same time.](b5335262987c819d7f71ce40f99cb71b_img.jpg) + +``` +sequenceDiagram + participant EF + participant CSAF + participant RLF + participant TOCF + participant CDF + participant RemoteNode as Remote node + + RemoteNode->>CDF: 1. Contents pre-distribution + CDF->>RLF: 2. Content registration + EF->>CSAF: 3. Content service access request + CSAF->>EF: 4. Authentication + CSAF->>EF: 5. Reply with live content information + EF->>EF: 6. Select content + EF->>CSAF: 7. Content information request + CSAF->>RLF: 8. Content location request + RLF->>RLF: 9. Selecting optimized content node(s) + RLF->>CSAF: 10. Content location information + CSAF->>EF: 11. Content location information + EF->>CDF: 12. Content buffer map request + CDF->>EF: 13. Content buffer map response + EF->>CDF: 14. Content delivery request + CDF->>EF: 15. Contents delivery + Note over EF, CDF: EF interacts with a series of CDFs at the same time +``` + +Sequence diagram showing the flow of accessing live streaming service through P2P CDN. The diagram involves six entities: EF, CSAF, RLF, TOCF, CDF, and Remote node. The flow consists of 15 steps: 1. Contents pre-distribution (Remote node to CDF), 2. Content registration (CDF to RLF), 3. Content service access request (EF to CSAF), 4. Authentication (CSAF to EF), 5. Reply with live content information (CSAF to EF), 6. Select content (EF), 7. Content information request (EF to CSAF), 8. Content location request (CSAF to RLF), 9. Selecting optimized content node(s) (RLF), 10. Content location information (RLF to CSAF), 11. Content location information (CSAF to EF), 12. Content buffer map request (EF to CDF), 13. Content buffer map response (CDF to EF), 14. Content delivery request (EF to CDF), 15. Contents delivery (CDF to EF). A note indicates that EF interacts with a series of CDFs at the same time. + +Y.2084(15)\_FII.8 + +**Figure II.8 – Flow of accessing live streaming service through P2P CDN** + +- 1) Remote node pre-distributes the resource to CDF. +- 2) CDF registers the content to RLF. +- 3) EF sends a content service access request to CSAF to get the live streaming service information (including the available channels, the price of the channels, the introduction of the channels, etc.). The ID and device type of the EF are included in the content service access request. The content service access request may also include the authentication information of the user. +- 4) CSAF checks the authentication information of EF. +- 5) CSAF replies to EF with the channel list which includes the information of payment and channel description. EF may present the information to the user. +- 6) EF selects the channel. + +- 7) EF sends a content location request to CSAF to get the location information of available content nodes. The content ID is included in the request. The request may also include the ID of the EF and authentication information. +- 8) CSAF requests the location information of the content from RLF. +- 9) RLF interacts with TOCF to request optimized location information. +- 10) RLF sends the optimized location information of the peers (both content nodes and UEs) to the CSAF. This information can be a peer list with the address of the peers (both content nodes and UEs). +- 11) CSAF forwards the content location information to EF. +- 12) EF interacts with the CDFs to request the buffer map of the content. +- 13) CDFs return the buffer map of this content to EF. +- 14) According to the buffer maps, EF requests chunks from multiple CDFs. +- 15) CDFs deliver the content of the channel to the requesting EF. + +#### II.4.2 VoD + +Figure II.9 shows the flow for a UE to access VoD service through CDN with P2P model. + +![Sequence diagram showing the flow for a UE to access VoD service through CDN with P2P model. The diagram involves six entities: EF, CSAF, RLF, TOCF, CDFs, and Content source. The flow consists of 15 steps: 1. Content pre-distribution (Content source to CDFs), 2. Content registration (CDFs to RLF), 3. Content service access request (EF to CSAF), 4. Authentication (CSAF to EF), 5. Reply with live content information (CSAF to EF), 6. Select content (EF), 7. Content information request (EF to CSAF), 8. Content location request (CSAF to RLF), 9. Selecting optimized content node(s) (RLF), 10. Content location information (RLF to CSAF), 11. Content location information (CSAF to EF), 12. Content buffer map request (EF to CDFs), 13. Content buffer map response (CDFs to EF), 14. Content delivery request (EF to CDFs), and 15. Contents delivery (CDFs to EF). A note indicates that EF interacts with a series of CDFs at the same time for steps 12-15.](05eb72d372e4bf78e3d6a64949d77bcc_img.jpg) + +``` + +sequenceDiagram + participant EF + participant CSAF + participant RLF + participant TOCF + participant CDFs + participant ContentSource as Content source + + ContentSource->>CDFs: 1. Content pre-distribution + CDFs->>RLF: 2. Content registration + EF->>CSAF: 3. Content service access request + CSAF->>EF: 4. Authentication + CSAF->>EF: 5. Reply with live content information + EF->>CSAF: 7. Content information request + CSAF->>RLF: 8. Content location request + RLF->>TOCF: 9. Selecting optimized content node(s) + RLF->>CSAF: 10. Content location information + CSAF->>EF: 11. Content location information + EF->>CDFs: 12. Content buffer map request + CDFs->>EF: 13. Content buffer map response + EF->>CDFs: 14. Content delivery request + CDFs->>EF: 15. Contents delivery + Note over EF, CDFs: EF interacts with a series of CDFs at the same time + +``` + +Sequence diagram showing the flow for a UE to access VoD service through CDN with P2P model. The diagram involves six entities: EF, CSAF, RLF, TOCF, CDFs, and Content source. The flow consists of 15 steps: 1. Content pre-distribution (Content source to CDFs), 2. Content registration (CDFs to RLF), 3. Content service access request (EF to CSAF), 4. Authentication (CSAF to EF), 5. Reply with live content information (CSAF to EF), 6. Select content (EF), 7. Content information request (EF to CSAF), 8. Content location request (CSAF to RLF), 9. Selecting optimized content node(s) (RLF), 10. Content location information (RLF to CSAF), 11. Content location information (CSAF to EF), 12. Content buffer map request (EF to CDFs), 13. Content buffer map response (CDFs to EF), 14. Content delivery request (EF to CDFs), and 15. Contents delivery (CDFs to EF). A note indicates that EF interacts with a series of CDFs at the same time for steps 12-15. + +Y.2084(15)\_FII.9 + +**Figure II.9 – Flow of accessing VoD service through P2P CDN** + +- 1) Content source pre-distributes the resource to CDF. + +- 2) CDF contacts RLF to register the content received. +- 3) EF sends a content service access request to CSAF to get the VoD service information (including the available videos, the price of the videos, the introduction of the videos, etc.). The ID and device type of the EF are included in the content service access request. The content service access request may also include the authentication information of the user. +- 4) CSAF checks the authentication information of EF. +- 5) CSAF replies to EF with the video list which includes the information of payment, video description. EF may present the information to the user. +- 6) EF selects the video. +- 7) EF sends a content location request to CSAF to get the location information of available content nodes. The content ID is included in the request. Since the video EF chooses may be pay video and different users may have different watch permissions for different videos, the request may also include the ID of the EF and authentication information. +- 8) CSAF requests the location information of the content from RLF. +- 9) RLF interacts with TOCF to request optimized location information. +- 10) RLF sends the optimized location information of the peers (both content nodes and UEs) to the CSAF. This information can be a peer list with the address of the peers (both content nodes and UEs). + +NOTE – The way to implement procedures 6-8 is optional, the content location request can be sent by EF or CSAF. + +- 11) CSAF forwards the content location information to EF. +- 12) EF interacts with the CDFs to request the buffer map of the content. +- 13) CDFs return the buffer map of this content to EF. +- 14) According to the buffer maps and the video play schedule, EF requests chunks from multiple CDFs. +- 15) CDFs send the requested chunks to EF. + +#### **II.4.3 File downloading** + +The flows for a UE to access file downloading service through CDN with P2P model is similar to clause II.4.2 flows except that the content type EF requests are different. Refer to clause II.4.2; this clause does not repeat the flows. + +### **II.5 Integration** + +In implementations, DSN CDF could also be used as the integration of the above four basic usages: integration of cache and CDN, integration of P2P cache and P2P CDN, integration of cache and P2P cache, integration of CDN and P2P CDN. + +There are usually two types of integration. One type is that two basic usages are co-located together in one DSN CDF, which chooses specific usage based on requests from the EFs. For example, CDF could be the integration of cache and P2P cache. If an EF requests HTTP content, CDF will act as a traditional cache to store the content from web servers for EFs' additional requests. If an EF requests P2P content, CDF could act as a P2P cache. Another example could be the integration of cache and CDN, in which case CDF acts as a CDN which has already obtained certain content from an original server. However, when an EF requests content that the CDF doesn't have, the CDF will act as a traditional cache to get and store the content from the server. + +The other type of integration is that two basic usages could be implemented in serial in one network to make content distribution more efficient. For example, a content distribution network could use CDFs as cache to store content from original content servers, and then use CDFs as CDN to distribute the content from caches to the edge of the network. This implementation could effectively reduce traffic from CDFs to original content servers. + +# Bibliography + +- [b-ITU-T Y Suppl.10] ITU-T Y-series Recommendations – Supplement 10 (2010), *ITU-T Y.2000-series – Supplement on distributed service network (DSN) use cases*. + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Terminals and subjective and objective assessment methods | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/Y/T-REC-Y.2085-201606-I_PDF-E/07b17a620c75522d53916a11e12d1bff_img.jpg b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/07b17a620c75522d53916a11e12d1bff_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..d3dc8bd65bbcfbead5252d7d2b9c97960eb1b50c --- /dev/null +++ b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/07b17a620c75522d53916a11e12d1bff_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:9e189e65292bed4463b58b2c433aea449dd71ef190c13a577b36ca749fca4c3e +size 3990 diff --git a/marked/Y/T-REC-Y.2085-201606-I_PDF-E/1439cb942d9e363bbb3161b5540dd8c6_img.jpg b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/1439cb942d9e363bbb3161b5540dd8c6_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..e875f7c01669e2d33993b25cc44216f8ce14986e --- /dev/null +++ b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/1439cb942d9e363bbb3161b5540dd8c6_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:d3285588c3912be67cb21f6987beda1131a573ae09d352cba8ca3634377ee5bf +size 52380 diff --git a/marked/Y/T-REC-Y.2085-201606-I_PDF-E/14a22f23ced8ba1d63ece69861dbaacc_img.jpg b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/14a22f23ced8ba1d63ece69861dbaacc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..b251589cf40ace6dacc78699abda475ccc29cb4a --- /dev/null +++ b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/14a22f23ced8ba1d63ece69861dbaacc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:f5a5181407216d035f79590e56aec9a16d90fff38afd14731b2addf225d041a7 +size 4098 diff --git a/marked/Y/T-REC-Y.2085-201606-I_PDF-E/4cc7cdce3d498d8b0ba033a9be24ade5_img.jpg b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/4cc7cdce3d498d8b0ba033a9be24ade5_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..dc3b6920efc032a07dd7d4a6b957690651210580 --- /dev/null +++ b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/4cc7cdce3d498d8b0ba033a9be24ade5_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:067f027252e49c0c807ef3bfeda59111eecdbdaa210d6c8f9d968179313b7b32 +size 68843 diff --git a/marked/Y/T-REC-Y.2085-201606-I_PDF-E/4e4be0bd8b235167902f2c03e41da651_img.jpg b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/4e4be0bd8b235167902f2c03e41da651_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..470a25114e04590490ab7d9ba18d30b913a8e341 --- /dev/null +++ b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/4e4be0bd8b235167902f2c03e41da651_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:ed0d10b1237c52317158bab5682e4ba00e35319c9ad752157ce2d1a860c38b3f +size 69262 diff --git a/marked/Y/T-REC-Y.2085-201606-I_PDF-E/5b8a756d9a71c35f17db8bcb90b438a3_img.jpg b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/5b8a756d9a71c35f17db8bcb90b438a3_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..33bbeb7b830cd73f0d3e56b3c077375c6b5fa5fd --- /dev/null +++ b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/5b8a756d9a71c35f17db8bcb90b438a3_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:cdc5c02120ec1b723b7b85f0dfdbb780f610bdaacbd7ff16b47f68ca6019a72b +size 62377 diff --git a/marked/Y/T-REC-Y.2085-201606-I_PDF-E/5cab96b2d23174c25919840ecd50aa48_img.jpg b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/5cab96b2d23174c25919840ecd50aa48_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..938e0b6f48037a6bf9d8ac6dd71277d53d4c0ef4 --- /dev/null +++ b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/5cab96b2d23174c25919840ecd50aa48_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:2bf4e8d630ba81b5acd741071d763ab7afb02784bb49c37021dd15d73c5049cd +size 52452 diff --git a/marked/Y/T-REC-Y.2085-201606-I_PDF-E/81a4cbf0b3c4cbc065efdf8f800dadde_img.jpg b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/81a4cbf0b3c4cbc065efdf8f800dadde_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..dbd511c33437eaa85fa956b64cd8695e889e8f05 --- /dev/null +++ b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/81a4cbf0b3c4cbc065efdf8f800dadde_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:6996ed704fc0d59aee8784e3a7c474a2e405f0a6a8997b840d87bfe7526a0c9f +size 62799 diff --git a/marked/Y/T-REC-Y.2085-201606-I_PDF-E/898fb89a50d9ec1dfb4e425c816976a7_img.jpg b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/898fb89a50d9ec1dfb4e425c816976a7_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..440871e67c2b1a6843be9824013c29d2ea48c6fe --- /dev/null +++ b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/898fb89a50d9ec1dfb4e425c816976a7_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:f6fc8d91179f6ce411f783b2a82c19261cea21e84431454e267b5fffb28e1014 +size 58608 diff --git a/marked/Y/T-REC-Y.2085-201606-I_PDF-E/b9ecbc3baefab13719e000faa6e0c7eb_img.jpg b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/b9ecbc3baefab13719e000faa6e0c7eb_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..de7b02ca0fe7d1a53d33b704e54fae188a850400 --- /dev/null +++ b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/b9ecbc3baefab13719e000faa6e0c7eb_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:b1dcb26783edcb3f34449c1db4506f9be44b7bc2fe8904d8c094949601aa8336 +size 58093 diff --git a/marked/Y/T-REC-Y.2085-201606-I_PDF-E/bd0b93e7a46ede276d0a3b79ac487bd9_img.jpg b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/bd0b93e7a46ede276d0a3b79ac487bd9_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..26d7b93d77e811f5c9118f2196463b65428271a9 --- /dev/null +++ b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/bd0b93e7a46ede276d0a3b79ac487bd9_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:2f6a1b403a00666fd99f015c36dae78b031db83d50607bba7bccb1f370adce31 +size 68360 diff --git a/marked/Y/T-REC-Y.2085-201606-I_PDF-E/c5452f95f3b28f1bfe29e84fbc2e1267_img.jpg b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/c5452f95f3b28f1bfe29e84fbc2e1267_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..5803a4e0ed777290871d43e0b8c99abb9e3858e3 --- /dev/null +++ b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/c5452f95f3b28f1bfe29e84fbc2e1267_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:e2a1dcaf0f1653429f0491d0c3ee5ad021aaed8474b8e3b00fb7c361324e1b4b +size 66481 diff --git a/marked/Y/T-REC-Y.2085-201606-I_PDF-E/c85ded401105f62f2d6ff26b3b5eb4af_img.jpg b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/c85ded401105f62f2d6ff26b3b5eb4af_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..f41196f7ff044c99c760763cae74cfb6e2faa720 --- /dev/null +++ b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/c85ded401105f62f2d6ff26b3b5eb4af_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:34c3a8ecefc0b47d1dbbdcb317adb419ba48b33143ec7daf310f10562a321f9b +size 76320 diff --git a/marked/Y/T-REC-Y.2085-201606-I_PDF-E/c914f51f4427bc672dd0526cfc90ebe9_img.jpg b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/c914f51f4427bc672dd0526cfc90ebe9_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..123f5521f4eea4bdbf9dcf852f31bad5b696be56 --- /dev/null +++ b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/c914f51f4427bc672dd0526cfc90ebe9_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:425bc264a2849565a95d32efd4d99426d47c41729cb4fd9c0446b8bc0fa76b2e +size 67691 diff --git a/marked/Y/T-REC-Y.2085-201606-I_PDF-E/cfda9df1319e04207eb28bcefd1dab7b_img.jpg b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/cfda9df1319e04207eb28bcefd1dab7b_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..829a6dd6209ee67b33c72928c6ce2b12b304df36 --- /dev/null +++ b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/cfda9df1319e04207eb28bcefd1dab7b_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:1ec9d905f8ffc949482c46c6f2b3ee079d28f981303eebdac4d2cfdff6bff577 +size 31168 diff --git a/marked/Y/T-REC-Y.2085-201606-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..4bf5946a28ef4f1d363c85b68c8100d21cc22694 --- /dev/null +++ b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:c92eefb5e78b89ae1de921572071124a8ecab651aca8248c9453067f97292e30 +size 31322 diff --git a/marked/Y/T-REC-Y.2085-201606-I_PDF-E/e354b57563dae469c00b412b2abdf765_img.jpg b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/e354b57563dae469c00b412b2abdf765_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..7d4c7bac2482488b7b3b8ea65ac22e3cc203736e --- /dev/null +++ b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/e354b57563dae469c00b412b2abdf765_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:3a2d17013bc53507983058ff3270b4f9091bb4062f6ccbbbb2d7b269c6adbb99 +size 125458 diff --git a/marked/Y/T-REC-Y.2085-201606-I_PDF-E/raw.md b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..a9638ff3738e366d69f43a54fb4d8290c26fdc21 --- /dev/null +++ b/marked/Y/T-REC-Y.2085-201606-I_PDF-E/raw.md @@ -0,0 +1,961 @@ + + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +## Y.2085 + +(06/2016) + +SERIES Y: GLOBAL INFORMATION +INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS +AND NEXT-GENERATION NETWORKS, INTERNET OF +THINGS AND SMART CITIES + +Next Generation Networks – Frameworks and functional +architecture models + +# --- **Distributed service networking service routing** + +Recommendation ITU-T Y.2085 + +## ITU-T Y-SERIES RECOMMENDATIONS + +## GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS, INTERNET OF THINGS AND SMART CITIES + +| | | +|--------------------------------------------------------------------|----------------------| +| GLOBAL INFORMATION INFRASTRUCTURE | | +| General | Y.100–Y.199 | +| Services, applications and middleware | Y.200–Y.299 | +| Network aspects | Y.300–Y.399 | +| Interfaces and protocols | Y.400–Y.499 | +| Numbering, addressing and naming | Y.500–Y.599 | +| Operation, administration and maintenance | Y.600–Y.699 | +| Security | Y.700–Y.799 | +| Performances | Y.800–Y.899 | +| INTERNET PROTOCOL ASPECTS | | +| General | Y.1000–Y.1099 | +| Services and applications | Y.1100–Y.1199 | +| Architecture, access, network capabilities and resource management | Y.1200–Y.1299 | +| Transport | Y.1300–Y.1399 | +| Interworking | Y.1400–Y.1499 | +| Quality of service and network performance | Y.1500–Y.1599 | +| Signalling | Y.1600–Y.1699 | +| Operation, administration and maintenance | Y.1700–Y.1799 | +| Charging | Y.1800–Y.1899 | +| IPTV over NGN | Y.1900–Y.1999 | +| NEXT GENERATION NETWORKS | | +| Frameworks and functional architecture models | Y.2000–Y.2099 | +| Quality of Service and performance | Y.2100–Y.2199 | +| Service aspects: Service capabilities and service architecture | Y.2200–Y.2249 | +| Service aspects: Interoperability of services and networks in NGN | Y.2250–Y.2299 | +| Enhancements to NGN | Y.2300–Y.2399 | +| Network management | Y.2400–Y.2499 | +| Network control architectures and protocols | Y.2500–Y.2599 | +| Packet-based Networks | Y.2600–Y.2699 | +| Security | Y.2700–Y.2799 | +| Generalized mobility | Y.2800–Y.2899 | +| Carrier grade open environment | Y.2900–Y.2999 | +| FUTURE NETWORKS | Y.3000–Y.3499 | +| CLOUD COMPUTING | Y.3500–Y.3999 | +| INTERNET OF THINGS AND SMART CITIES AND COMMUNITIES | | +| General | Y.4000–Y.4049 | +| Definitions and terminologies | Y.4050–Y.4099 | +| Requirements and use cases | Y.4100–Y.4249 | +| Infrastructure, connectivity and networks | Y.4250–Y.4399 | +| Frameworks, architectures and protocols | Y.4400–Y.4549 | +| Services, applications, computation and data processing | Y.4550–Y.4699 | +| Management, control and performance | Y.4700–Y.4799 | +| Identification and security | Y.4800–Y.4899 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +## Recommendation ITU-T Y.2085 + +# Distributed service networking service routing + +## Summary + +Recommendation ITU-T Y.2085 specifies the architecture for service routing functions (SRF). Service routing supports the service registration, discovery, and triggering and access mechanisms in the environment of distributed service networking (DSN) as described in Recommendation ITU-T Y.2080. + +The main objectives of this Recommendation are to specify: + +- Functional entities of SRF; +- Reference points of SRF; +- Information flows between SRF and other functions defined in DSN. + +## History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|----------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T Y.2085 | 2016-06-13 | 13 | 11.1002/1000/12887 | + +## Keywords + +Distributed service networking, DSN, functional architecture, service routing, service routing function, SRF. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. For example, . + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2016 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | | Page | +|---|--------------------------------------------------------------------------------|------| +| 1 | Scope..... | 1 | +| 2 | References..... | 1 | +| 3 | Definitions ..... | 1 | +| | 3.1 Terms defined elsewhere..... | 1 | +| | 3.2 Terms defined in this Recommendation..... | 1 | +| 4 | Abbreviations and acronyms ..... | 2 | +| 5 | Conventions ..... | 2 | +| 6 | Requirements of service routing over DSN..... | 3 | +| 7 | Functional architecture of service routing ..... | 4 | +| | 7.1 Functional architecture ..... | 4 | +| | 7.2 Reference point and interface ..... | 4 | +| 8 | Basic information flows..... | 5 | +| | 8.1 Description ..... | 5 | +| | 8.2 Service bootstrap ..... | 5 | +| | 8.3 Service directory discovery ..... | 6 | +| | 8.4 Service registration..... | 7 | +| | 8.5 Service update ..... | 8 | +| | 8.6 Service deregistration ..... | 9 | +| | 8.7 Service query ..... | 10 | +| | 8.8 Service access..... | 11 | +| 9 | Security considerations..... | 11 | +| | Appendix I – How DSN service routing contributes to the Internet service ..... | 12 | +| | I.1 DSN service routing as a service store for Internet service..... | 12 | +| | I.2 DSN service routing as PaaS platform for Internet service..... | 12 | +| | Appendix II – DSN Service routing scenarios and benefits ..... | 13 | +| | II.1 Use cases related to service access ..... | 13 | +| | II.2 Service interconnection ..... | 16 | +| | II.3 Service store use case ..... | 17 | +| | Appendix III – An illustration of service profile's structure ..... | 19 | +| | Bibliography..... | 20 | + + + +# Recommendation ITU-T Y.2085 + +# Distributed service networking service routing + +# 1 Scope + +This Recommendation specifies service routing functions (SRF), which provide service registration, discovery, triggering and access mechanisms through distributed service networking (DSN), and the capabilities to improve service provision including load balance, charging agent, etc. Moreover, it describes the related reference points and possible protocols between functional entities in detail, and also defines detailed message flows of service routing. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[ITU-T Y.2080] Recommendation ITU-T Y.2080 (2012), *Functional architecture for distributed service networking*. + +[ITU-T Y.2701] Recommendation ITU-T Y.2701 (2007), *Security requirements for NGN release 1*. + +# 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 distributed service networking** [b-ITU-T Y.2206]: An overlay network which provides distributed and manageable capabilities to support various multimedia services. + +**3.1.2 functional entity** [b-ITU-T Y.2012]: An entity that comprises an indivisible set of specific functions. Functional entities are logical concepts, while groupings of functional entities are used to describe practical, physical implementations. + +## 3.2 Terms defined in this Recommendation + +This Recommendation defines the following terms: + +**3.2.1 service directory:** An entity to accept the service registration requirement from an application server (AS) and supply the service/application list to the users. + +**3.2.2 service ID:** A hash ID representing a certain service which will be registered in DSN. + +**3.2.3 service routing:** A unified service supporting platforms built on DSN. It supplies the service registration, publication, discovery, triggering and access mechanisms, and enhanced capabilities to optimize the service provision. + +# 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|-------|----------------------------------------| +| AS | Application Server | +| CDF | Content Delivery Functions | +| CSAF | Content Service Application Functions | +| DHT | Distributed Hash Table | +| DSN | Distributed Service Networking | +| EF | End-user Functions | +| PaaS | Platform as a Service | +| P2P | Peer-to-Peer | +| RLF | Resource Location Functions | +| SCF | Service Control Functions | +| SD-FE | Service Directory Functional Entity | +| SP | Service Provider | +| SRF | Service Routing Functions | +| SR-FE | Service Routing Functional Entity | +| TOCF | Traffic Optimization Control Functions | +| UE | User Equipment | + +# 5 Conventions + +The following conventions apply: + +- 1) The meaning of functions is as follows: + +**Functions:** In the context of DSN functional architecture, "functions" are defined as a functional group composed of functional entities. It is represented by the following symbol: + +![A rounded rectangular box containing the word 'Functions'.](07b17a620c75522d53916a11e12d1bff_img.jpg) + +A diagram showing a rounded rectangular box with a black border. Inside the box, the word "Functions" is written in a black, sans-serif font, centered horizontally and vertically. + +A rounded rectangular box containing the word 'Functions'. + +- 2) In this Recommendation: + +DSN network means the network constructed based on DSN principles. + +DSN service means the service supported by the DSN network. + +DSN application server (AS) means the application server providing the DSN service. + +DSN service provider (SP) means the service provider that makes use of the DSN network in order to provide services and applications to its users. + +# **6 Requirements of service routing over DSN** + +DSN-based service routing provides service bootstrap, service registration, publication, discovery, triggering and access mechanism, and capabilities to optimize the service provision. It should support the following functional requirements: + +- 1) From the aspect of a basic mechanism, service routing is required to support: + - a) Service bootstrap +The DSN AS executes a bootstrap procedure before registering to DSN. The bootstrap enables service initialization, which selects and ensures the operation of the service. The AS can get the access information of DSN from the bootstrap. + - b) Service registration and publication +The DSN AS registers in DSN and is published by DSN with a unified service ID. + - c) Service discovery +The DSN service is discovered by its service ID. + - d) Service directory discovery +Service directory is discovered by the DSN AS/end-user functions (EF). + - e) Service update +The DSN service updates the service information registered in DSN. + - f) Service triggering and access +The DSN service is triggered and accessed by the user through its service ID. + - g) Service deregistration +The DSN AS deregisters and removes the service information in DSN. +- 2) From the aspect of the capability to improve service provision, service routing is recommended to support: + - a) Unified user authentication and authorization for DSN and service provider + - b) Load balance +Based on the load balance of application servers, service routing can select the suitable AS for the users to access service. +Service routing can select the AS in a suitable location to optimize the service provision when application servers are distributed in various places. + - c) Charging +When a user accesses the service, DSN can act as the charging agent for the service providers. + +# 7 Functional architecture of service routing + +### 7.1 Functional architecture + +![Figure 7-1: SRF functional architecture diagram. The diagram shows a central 'Service routing functions' block containing 'SD-FE (Service directory FE)' and 'SR-FE (Service routing FE)'. This block is connected to 'AS/EF' via interface C8. It is connected to 'CSAF' via interface A6. Below the central block, it connects to 'SCF' via C11, 'RLF' via C12, and 'TOCF' via C13.](cfda9df1319e04207eb28bcefd1dab7b_img.jpg) + +``` +graph TD + CSAF[CSAF] <-->|A6| SRF[Service routing functions] + subgraph SRF [Service routing functions] + SD_FE[SD-FE +(Service directory FE)] + SR_FE[SR-FE +(Service routing FE)] + end + AS_EF[AS/EF] <-->|C8| SRF + SRF <-->|C11| SCF[SCF] + SRF <-->|C12| RLF[RLF] + SRF <-->|C13| TOCF[TOCF] +``` + +Y.2085(16)\_F7-1 + +Figure 7-1: SRF functional architecture diagram. The diagram shows a central 'Service routing functions' block containing 'SD-FE (Service directory FE)' and 'SR-FE (Service routing FE)'. This block is connected to 'AS/EF' via interface C8. It is connected to 'CSAF' via interface A6. Below the central block, it connects to 'SCF' via C11, 'RLF' via C12, and 'TOCF' via C13. + +**Figure 7-1 – SRF functional architecture** + +Figure 7-1 describes the service routing functions (SRF) functional architecture with functional entities and relevant reference points. This functional architecture includes: + +- Service directory functional entity (SD-FE). +- Service routing functional entity (SR-FE). + +#### 7.1.1 Service directory functional entity + +The SD-FE handles the following functions: + +- The SD-FE supports the service registration from the SP. The SD-FE allocates service ID for the service and stores the detailed information of the registered service to the DSN through resource location functions (RLF). +- The SD-FE provides service access portal function to the user equipment (UE). When the UE queries a service, the SD-FE provides the service menu list to the UE. Once the UE chooses one service, the SD-FE sends the service ID to the UE. + +#### 7.1.2 Service routing functional entity + +The SR-FE provides the service triggering and access mechanisms, and enhanced capabilities to optimize the service provision. + +The SR-FE provides service information storage and management functions for the service. The service information contains the address, work load of application server, etc. + +The SR-FE provides user authentication and authorization functions for the AS. + +The SR-FE provides service triggering functions when the UE requests access from DSN. The SR-FE queries the service information through RLF by the service ID. + +The SR-FE chooses the suitable AS according to load balance and geography factors. + +The SR-FE provides confidential charging functions for the application providers. + +### 7.2 Reference point and interface + +#### 7.2.1 Interface C8 + +The SR-FE interacts with the AS/EF via the reference point C8 to accept AS/EF connection requests, accept AS/EF service access requests and return the service access responses to the AS/EF. + +The SD-FE interacts with the AS/EF via the reference point C8 to accept AS/EF service requests and return service responses to the AS/EF. + +#### **7.2.2 Interface C11** + +The SR-FE interacts with service control functions (SCF) via the reference point C11 to retrieve user profile and authentication information. + +#### **7.2.3 Interface C12** + +The SR-FE interacts with RLF via the reference point C12 to locate the responsible SR-FE based on a given service ID. + +#### **7.2.4 Interface C13** + +The SR-FE interacts with traffic optimization control functions (TOCF) via the reference point C13 to query network topology information for application server selection. + +#### **7.2.5 Interface A6** + +The SR-FE interacts with content service application functions (CSAF) via the reference point A6 to accept CSAF connection requests, accept CSAF service access requests and return the service access responses to the CSAF. + +The SD-FE interacts with the CSAF via the reference point A6 to accept CSAF service requests and return the service responses to the CSAF. + +# **8 Basic information flows** + +### **8.1 Description** + +Service routing provides the mechanisms of service bootstrap, service registration, publication, discovery, triggering and access through DSN. Through the collaboration of DSN providers and the SPs, service routing can help to optimize the service provision by supplying the capabilities of service load balance, service management, etc. Service routing can also provide charging functions and other enhanced functions for the SPs under the participation of DSN. + +In service routing, a user will discover and access the service by the service ID, and DSN will process charging and load balance based on the service ID. + +The detailed information flows are described as follows. + +### **8.2 Service bootstrap** + +The bootstrap flow is executed before the AS registers itself to the service routing network as a server, or executes before EF accesses a service through the service routing network. + +![Sequence diagram for Service bootstrap (Figure 8-1). The diagram shows an Application server/EF interacting with two SRFs (Service Resource Functions). The first SRF contains an SD-FE (Service Directory Function Element). The second SRF contains an SR-FE A (Service Resource Function Element A). The sequence of messages is: 1. Application server/EF sends '1. Get SR-FE list, select SR-FE for access' to the first SRF. 2. Application server/EF sends '2. Access request' to SR-FE A. 3. SR-FE A sends '3. Access response' back to the Application server/EF.](d4af765160d04ecef538e5066006dc77_img.jpg) + +``` + +sequenceDiagram + participant AS as Application server/EF + participant SRF1 as SRF (SD-FE) + participant SRF2 as SRF (SR-FE A) + Note over AS, SRF1: 1. Get SR-FE list, select SR-FE for access + AS->>SRF2: 2. Access request + SRF2-->>AS: 3. Access response + +``` + +Y.2085(16)\_F8-1 + +Sequence diagram for Service bootstrap (Figure 8-1). The diagram shows an Application server/EF interacting with two SRFs (Service Resource Functions). The first SRF contains an SD-FE (Service Directory Function Element). The second SRF contains an SR-FE A (Service Resource Function Element A). The sequence of messages is: 1. Application server/EF sends '1. Get SR-FE list, select SR-FE for access' to the first SRF. 2. Application server/EF sends '2. Access request' to SR-FE A. 3. SR-FE A sends '3. Access response' back to the Application server/EF. + +**Figure 8-1 – Service bootstrap** + +- 1) Application server/EF gets an SR-FE list and selects one SR-FE for access. +- 2) Application server/EF sends a connect request to the selected SR-FE, and creates a connection successfully. +- 3) Application server/EF gets the access information from the SR-FE, such as local profile, remote profile server. + +### 8.3 Service directory discovery + +![Sequence diagram for Service directory discovery (Figure 8-2). The diagram shows an Application server/EF interacting with four entities: SRF (SD-FE), SRF (SR-FE A), RLF (Resource Location Function), and SRF (SR-FE B). The sequence of messages is: 1. Application server/EF sends '1. Service access request' to SR-FE A. 2. SR-FE A sends '2. P2P query request' to SR-FE B. 3. SR-FE B sends '3. P2P query response' back to SR-FE A. 4. SR-FE A sends '4. Service access response' back to the Application server/EF. 5. Application server/EF sends '5. Service request' to SD-FE. 6. SD-FE sends '6. Service response' back to the Application server/EF.](1439cb942d9e363bbb3161b5540dd8c6_img.jpg) + +``` + +sequenceDiagram + participant AS as Application server/EF + participant SRF1 as SRF (SD-FE) + participant SRF2 as SRF (SR-FE A) + participant RLF as RLF + participant SRF3 as SRF (SR-FE B) + AS->>SRF2: 1. Service access request + SRF2->>SRF3: 2. P2P query request + SRF3-->>SRF2: 3. P2P query response + SRF2-->>AS: 4. Service access response + AS->>SRF1: 5. Service request + SRF1-->>AS: 6. Service response + +``` + +Y.2085(16)\_F8-2 + +Sequence diagram for Service directory discovery (Figure 8-2). The diagram shows an Application server/EF interacting with four entities: SRF (SD-FE), SRF (SR-FE A), RLF (Resource Location Function), and SRF (SR-FE B). The sequence of messages is: 1. Application server/EF sends '1. Service access request' to SR-FE A. 2. SR-FE A sends '2. P2P query request' to SR-FE B. 3. SR-FE B sends '3. P2P query response' back to SR-FE A. 4. SR-FE A sends '4. Service access response' back to the Application server/EF. 5. Application server/EF sends '5. Service request' to SD-FE. 6. SD-FE sends '6. Service response' back to the Application server/EF. + +**Figure 8-2 – Service directory discovery** + +- 1) While an application server/EF does not have the address of the SD-FE, the application server/EF first sends a service access request message to its associated SR-FE, e.g., SR-FE A, to find the SD-FE. The service access request message contains a service ID which is allocated for service directory. + +NOTE – The ID for service can be pre-stored in the application server/EF. + +- 2) SR-FE A sends a fetch request to the responsible SR-FE of the service information, i.e., SR-FE B, over peer-to-peer (P2P) overlay. +- 3) SR-FE B returns the P2P query response. +- 4) SR-FE A returns the service directory information to the application server/EF. +- 5) The application server/EF connects to the service directory, i.e., SD-FE, and sends a service request to retrieve the service list or lookup the service information. +- 6) SD-FE returns the service response to the application server/EF. + +### 8.4 Service registration + +![Sequence diagram for Service registration showing interactions between Application server, SRF (SD-FE), SRF (SR-FE A), RLF, and SRF (SR-FE B).](4e4be0bd8b235167902f2c03e41da651_img.jpg) + +``` +sequenceDiagram + participant AS as Application server + participant SRF1 as SRF (SD-FE) + participant SRF2 as SRF (SR-FE A) + participant RLF as RLF + participant SRF3 as SRF (SR-FE B) + + AS->>SRF1: 1. Service registration request + Note over SRF1: 2. Authentication and service ID allocation + SRF1->>SRF2: 3. Service information storage request + SRF2->>RLF: 4. P2P store request + RLF->>SRF3: 5. P2P store response + SRF2->>SRF1: 6. Service information storage response + Note over SRF1: 7. Update service directory + SRF1->>AS: 8. Service registration response +``` + +Y.2085(16)\_F8-3 + +Sequence diagram for Service registration showing interactions between Application server, SRF (SD-FE), SRF (SR-FE A), RLF, and SRF (SR-FE B). + +**Figure 8-3 – Service registration** + +- 1) Application server sends the service registration request to the SD-FE to publish a specified service. The service information, including the application server address and service description, is contained in the message. +- 2) SD-FE authenticates the application server and allocates a service ID for the new service. +- 3) SD-FE sends a service information storage request to its associated SR-FE A. The service information, including service ID, application server address and service description, is contained in the message. +- 4) SR-FE A sends a store request to the responsible SR-FE of the service information, i.e., SR-FE B, over P2P overlay. +- 5) SR-FE B stores the information of the service and returns the P2P storage response. +- 6) SR-FE A returns the service information storage response. +- 7) SD-FE updates the service directory so that the new service is on the list. +- 8) SD-FE returns the service registration response to the application server to show that the registration is successful. The allocated service ID is included in the response. + +### 8.5 Service update + +![Sequence diagram for Service update process](b9ecbc3baefab13719e000faa6e0c7eb_img.jpg) + +The diagram illustrates the service update process involving several components: Application server, SRF (containing SD-FE), SRF (containing SR-FE A), RLF, and SRF (containing SR-FE B). The process follows these steps: + +1. Service update request: Application server sends a request to SD-FE. +2. Authentication: SD-FE authenticates the application server. +3. Service information storage request: SD-FE sends a request to SR-FE A. +4. P2P store request: SR-FE A sends a request to SR-FE B. +5. P2P store response: SR-FE B sends a response to SR-FE A. +6. Service information storage response: SR-FE A sends a response to SD-FE. +7. Service update response: SD-FE sends a response to the application server. + +Sequence diagram for Service update process + +Y.2085(16)\_F8-4 + +**Figure 8-4 – Service update** + +- 1) Application server sends the service update request to the SD-FE to update the service information, e.g., add/delete application servers, change server load status. The service ID and updated service information are contained in the message. +- 2) SD-FE authenticates the application server. +- 3) SD-FE sends a service information storage request to its associated SR-FE A. The service ID and updated service information are contained in the message. +- 4) SR-FE A sends a store request to the responsible SR-FE of the service information over P2P overlay, i.e., SR-FE B. +- 5) SR-FE B stores the information of the service and returns the P2P storage response. +- 6) SR-FE A returns the service information storage response. +- 7) SD-FE returns the service update response to the application server to show that the update was successful. + +### 8.6 Service deregistration + +![Sequence diagram for Service deregistration showing interactions between Application server, SD-FE, SR-FE A, RLF, and SR-FE B.](bd0b93e7a46ede276d0a3b79ac487bd9_img.jpg) + +``` + +sequenceDiagram + participant AS as Application server + participant SRF1 as SRF +SD-FE + participant SRF2 as SRF +SR-FE A + participant RLF as RLF + participant SRF3 as SRF +SR-FE B + + AS->>SRF1: 1. Service deregistration request + Note over SRF1: 2. Authentication + SRF1->>SRF2: 3. Service information storage request + SRF2->>RLF: 4. P2P remove request + RLF->>SRF3: 4. P2P remove request + SRF3-->>RLF: 5. P2P remove response + RLF-->>SRF2: 5. P2P remove response + SRF2-->>SRF1: 6. Service information storage response + Note over SRF1: 7. Update service directory + SRF1-->>AS: 8. Service deregistration response + +``` + +The diagram illustrates the service deregistration process. It involves an Application server, three Service Routing Function (SRF) entities (SD-FE, SR-FE A, and SR-FE B), and a Routing Location Function (RLF). The process follows these steps: 1. The Application server sends a service deregistration request to the SD-FE. 2. The SD-FE performs authentication. 3. The SD-FE sends a service information storage request to SR-FE A. 4. SR-FE A sends a P2P remove request to the RLF, which then forwards it to SR-FE B. 5. SR-FE B returns a P2P remove response to the RLF, which forwards it back to SR-FE A. 6. SR-FE A returns a service information storage response to the SD-FE. 7. The SD-FE updates its service directory. 8. Finally, the SD-FE sends a service deregistration response back to the Application server. + +Sequence diagram for Service deregistration showing interactions between Application server, SD-FE, SR-FE A, RLF, and SR-FE B. + +Y.2085(16)\_F8-5 + +**Figure 8-5 – Service deregistration** + +- 1) Application server sends the service deregistration request to the SD-FE to cancel the service from service routing network. +- 2) SD-FE authenticates the application server. +- 3) SD-FE sends a service information storage request to its associated SR-FE A to remove the service information. +- 4) SR-FE A sends a remove request to the responsible SR-FE of the service information, i.e., SR-FE B, over P2P overlay. +- 5) SR-FE B removes the information of the service and returns the P2P remove response. +- 6) SR-FE A returns the service information storage response. +- 7) SD-FE updates the service directory so that the service is removed from the list. +- 8) SD-FE returns the service deregistration response to the application server to show that deregistration was successful. + +### 8.7 Service query + +![Sequence diagram for Service query process](5cab96b2d23174c25919840ecd50aa48_img.jpg) + +The diagram illustrates the service query process involving five entities: Application server/EF, SD-FE, SR-FE A, RLF, and SR-FE B. The process follows these steps: + +1. Service query request: Application server/EF sends a request to SD-FE. +2. Service query request: SD-FE sends a request to SR-FE A. +3. P2P query request: SR-FE A sends a request to SR-FE B. +4. P2P query response: SR-FE B sends a response to SR-FE A. +5. Service query response: SR-FE A sends a response to SD-FE. +6. Service query response: SD-FE sends a response to Application server/EF. + +Y.2085(16)\_F8-6 + +Sequence diagram for Service query process + +**Figure 8-6 – Service query** + +- 1) Application server/EF queries information about a service. The application server/EF sends the service query request with the service ID to the SD-FE. The requested service information includes the service name, and/or application server list, etc. +- 2) SD-FE authenticates the application server/EF and sends the service query request to its associated SR-FE A. +- 3) SR-FE A sends a fetch request to the responsible SR-FE of the service information, i.e., SR-FE B, over P2P overlay. +- 4) SR-FE B returns the P2P query response. +- 5) SR-FE A returns the service query response. +- 6) SD-FE returns service query response to the application server or EF. The requested service information is included in the response. + +### 8.8 Service access + +![Sequence diagram illustrating the service access process between various network entities.](c85ded401105f62f2d6ff26b3b5eb4af_img.jpg) + +``` + +sequenceDiagram + participant AS as Application server + participant EF + participant SD_FE as SRF SD-FE + participant SR_FE_A as SRF SR-FE A + participant RLF + participant SR_FE_B as SRF SR-FE B + + EF->>SD_FE: 1. Service request + SD_FE-->>EF: 2. Service response + EF->>SR_FE_A: 3. Service access request + Note over SR_FE_A: 4. Authorization + SR_FE_A->>SR_FE_B: 5. P2P query request + SR_FE_B-->>SR_FE_A: 6. P2P query response + Note over SR_FE_A: 7. Application server selection + SR_FE_A->>AS: 8. Service access request + AS-->>SR_FE_A: 9. Service access response + SR_FE_A-->>EF: 10. Service access response + +``` + +Y.2085(16)\_F8-7 + +Sequence diagram illustrating the service access process between various network entities. + +**Figure 8-7 – Service access** + +- 1) When the EF wants to access service, it first sends service request to the SD-FE. +- 2) SD-FE sends a service response to the EF with basic service information including service ID. +- 3) EF sends a service access request to the SR-FE A with the service ID. The SR-FE A is the access SR-FE for the EF. +- 4) SR-FE A executes the authentication and authorization function and checks the user profile to determine if the EF has the right to access this service. +- 5) SR-FE A sends a fetch request to the responsible SR-FE B of the service information, i.e., SR-FE B, over P2P overlay. +- 6) SR-FE B sends the P2P query response to the SR-FE A. The response message includes detailed service information, e.g., the application servers' access address, load, and location. +- 7) SR-FE A selects an application server according to location, load balance, etc. +- 8) SR-FE A sends a service access request to the selected application server. +- 9) Application server sends the service access response to the SR-FE A. +- 10) SR-FE A forwards the service access response to the EF to start the service. + +# 9 Security considerations + +This Recommendation requires no specific considerations and aligns with the security requirements in [ITU-T Y.2701]. + +# Appendix I + +## How DSN service routing contributes to the Internet service + +(This appendix does not form an integral part of this Recommendation.) + +DSN can provide P2P-based multimedia telephony service (MMTel) service control and support to streaming services. However, for Internet services, it is hard to have a network stratum to control the services, as NGN currently does. A new business model and a new ecosystem should consider how DSN could provide for Internet services in the future. + +DSN service routing tries to solve this problem by presenting two mechanisms: + +- 1) DSN service routing helps to publish the Internet service based on the carrier's subscribers. In this case, DSN service routing works as a service store for the Internet service. +- 2) DSN service routing opens some mature function components to the Internet service providers to facilitate Internet service development and provision. In this case, DSN service routing works as a platform as a service (PaaS) platform for the Internet service. + +### I.1 DSN service routing as a service store for Internet service + +Telecommunication carriers have a large number of subscribers who could be the potential users of the Internet service. + +DSN service routing provides a publication platform so that DSN subscribers can easily check out their favourite service and can easily access the service. + +### I.2 DSN service routing as PaaS platform for Internet service + +Except for the core service logic implementation, most service providers are not rigorous in their accounting system, load balance, user management, and other such ancillary functions. + +DSN service routing can provide many mature capability components for Internet service, including but not limited to: + +- 1) Unified user account management +DSN service routing can provide user authentication and authorization functions for the SP. +- 2) Charging proxy +DSN service routing can provide a secure and confidential charging mechanism for the SP. +- 3) Work load information monitoring and load balance mechanisms +Often there are many application servers necessary to provide a single service. DSN service routing can monitor the work load of the application servers and select the suitable servers. The geography factors can also be considered during the load balance procedure. +- 4) Service data storage +DSN service routing can provide data storage capability to the SPs so that they do not need to build their own storage systems. +- 5) Network topology and the user location information +DSN service routing can provide the user location service. DSN service routing can also provide traffic optimization based on the network topology information, perhaps with the help of DSN TOCF. + +Based on the above mechanisms, DSN service routing can help Internet service providers focus on their core business development. It works in a different way to inter-operate with services as compared with NGN (while it is what the future Internet service environment needs). + +# Appendix II + +## DSN Service routing scenarios and benefits + +(This appendix does not form an integral part of this Recommendation.) + +### II.1 Use cases related to service access + +Figure II.1 shows UE access service through DSN service routing. In this clause, the DSN service routing use cases, during the service access procedure, are described. + +![Figure II.1 – Service access diagram](898fb89a50d9ec1dfb4e425c816976a7_img.jpg) + +The diagram illustrates the service access process. On the left, a 'Service directory' box contains a 'Service directory' entry. In the center, the 'DSN core domain' is represented by a grey rectangle containing three 'Core node' boxes connected in a triangular mesh. Above this domain, 'Service provider A' is shown in a blue box containing three 'Application server' boxes (labeled 1, 2, and 3). Each application server has a map icon. An arrow points from 'Application server 3' to the rightmost 'Core node' in the DSN core domain. To the right of the DSN core domain, a 'UE' (User Equipment) is shown as a mobile phone icon, with a bidirectional arrow connecting it to the same rightmost 'Core node'. + +Y.2085(16)\_FII.1 + +Figure II.1 – Service access diagram + +Figure II.1 – Service access + +#### II.1.1 Unified user authentication and authorization + +When the UE chooses a service from the service directory, the UE can connect to the DSN core node and request the service. Before the UE accesses the service, DSN will check if the UE can access this service for the SP. Only if the UE passes the DSN authentication and authorization, it can access the service. + +As shown in Figure II.1, service provider A (hereafter, SP A) provides the map service. SP A signed a contract with the DSN provider, so SP A trusts in the subscribers of DSN. When the UE passes the DSN authentication and authorization, SP A will accept the UE's service request through DSN. + +Compared with traditional service access, the UE should register with individual SPs and authenticate separately. In this case, it could improve the service access efficiency. + +#### II.1.2 Charging + +When the UE accesses a service for payment, the DSN core node can charge the user with his/her DSN account and then settle accounts with the SP later. + +Petty account charging could be typical for this use case. Examples are given as follows: + +- 1) The UE wants to download e-books from SP A and will be charged some money for every e-book downloaded. When the UE send a service request to SP A and confirms a download e-book, DSN will charge the UE to his DSN subscriber account and will settle accounts with SP A later. DSN can require commission charges from SP A. +- 2) SP B is an online game provider and also sells game currencies, time cards and virtual items. Players can pay through their DSN subscriber account when can access service through DSN. + +- 3) SP C provides a map navigation service. When a user accesses this service through DSN service routing, they can choose to pay via their DSN account. + +#### II.1.3 Load balance + +A DSN node can keep alive with the application servers and update the work load information of the application server periodically. When DSN chooses the application server for the UE, the application server with the lower work load will be selected with a higher priority. + +![Figure II.2 – Load balance diagram](81a4cbf0b3c4cbc065efdf8f800dadde_img.jpg) + +The diagram illustrates a load balancing scenario. On the left, a 'Service directory' box contains a 'Service directory' label. In the center, a 'DSN core domain' box contains three 'Core node' boxes connected in a triangular mesh. To the right, a 'UE' (User Equipment) is represented by a mobile phone icon. Above the DSN core domain, a 'Service provide A' box contains three 'Application server' boxes. Each server has a red cylinder icon indicating its workload: 'Application server 1' and 'Application server 2' are at 90%, and 'Application server 3' is at 50%. Arrows show the flow of service requests: from the UE to a core node, then to the core node with the lightest workload (the rightmost one), and finally to 'Application server 3'. The label 'Y.2085(16)\_FII.2' is located at the bottom right of the diagram. + +Figure II.2 – Load balance diagram + +**Figure II.2 – Load balance** + +As shown in the Figure II.2, SP A deployed three application servers to provide the map service. Each application service has a different workload. As shown, application server 1 and application server 2 have already been heavily burdened while application server 3 can still accept more service visits. + +When the UE wants to access the service, DSN core node checks the current work status of the application servers and finds application server 3 has the lightest workload. Thus, application server 3 is selected as the service server for the UE. In the next step, the UE will receive service from application server 3. + +#### II.1.4 Optimization based on location + +When DSN chooses the application server for the UE, the location of the application servers and the UE will be considered. The application server geographically closest to the UE will be selected with a higher priority. + +As shown in Figure II.3, SP A deploys three application servers to provide the map service. Application server 1~3 is located in Paris, Vancouver, and Beijing, respectively. + +When a UE located in China requests the map service, DSN core node will select the application server 3 to provide the service. + +![Figure II.3 – Location optimization by TOCF. The diagram shows a Service provider A with three application servers (1, 2, 3). A Service directory is connected to a DSN core domain. The DSN core domain contains three core nodes: one with TOCF and two others. A UE (User Equipment) is connected to the core node with TOCF. Arrows indicate the flow of information: 1. UE to core node with TOCF; 2. core node with TOCF to core node; 3. core node with TOCF to application server 3.](5b8a756d9a71c35f17db8bcb90b438a3_img.jpg) + +Service provider A + +Application server 1 Application server 2 Application server 3 + +Service directory + +Service directory + +DSN core domain + +Core node with TOCF + +Core node + +Core node + +UE + +Y.2085(16)\_FII.3 + +Figure II.3 – Location optimization by TOCF. The diagram shows a Service provider A with three application servers (1, 2, 3). A Service directory is connected to a DSN core domain. The DSN core domain contains three core nodes: one with TOCF and two others. A UE (User Equipment) is connected to the core node with TOCF. Arrows indicate the flow of information: 1. UE to core node with TOCF; 2. core node with TOCF to core node; 3. core node with TOCF to application server 3. + +**Figure II.3 – Location optimization by TOCF** + +In this use case, DSN service routing can cooperate with TOCF to find the geographically-closest application server. + +For example, DSN core node sends the application server list to the TOCF. The TOCF will check and find application server 3 is closest to the UE, and then the TOCF will return the application server 3 as the best selection. + +#### II.1.5 Service personalization + +A DSN node can gather service usage information when a user accesses service through DSN. Using the per-user service usage information, e.g., service access frequency and service type, DSN service routing system can use data mining technology to derive the user preference. Therefore, DSN can provide more personalized services to its users. The user preference profile can be open to services managed by the DSN operator and third-party services. When user privacy is concerned, such information may only be used by trusted services managed by DSN operators. + +![Figure II.4 – Personalized advertisement push. The diagram shows an Advertisement provider with an advertisement server 1. A Service analyzer with two analyzers (1, 2) is connected to a DSN core domain. The DSN core domain contains three core nodes. A UE (User Equipment) is connected to the core node. Arrows indicate the flow of information: 1. UE to core node; 2. core node to service analyzer; 3. service analyzer to core node; 4. core node to advertisement server 1; 5. advertisement server 1 to UE.](4cc7cdce3d498d8b0ba033a9be24ade5_img.jpg) + +Advertisement provider + +Advertisement server 1 + +Service analyzer + +Analyzer 1 Analyzer 2 + +4. Advertisement service + +3. User preference profile + +2. Service usage information + +DSN core domain + +Core node + +Core node + +Core node + +1. Service access + +5. Advertisement push + +UE + +Y.2085(16)\_FII.4 + +Figure II.4 – Personalized advertisement push. The diagram shows an Advertisement provider with an advertisement server 1. A Service analyzer with two analyzers (1, 2) is connected to a DSN core domain. The DSN core domain contains three core nodes. A UE (User Equipment) is connected to the core node. Arrows indicate the flow of information: 1. UE to core node; 2. core node to service analyzer; 3. service analyzer to core node; 4. core node to advertisement server 1; 5. advertisement server 1 to UE. + +**Figure II.4 – Personalized advertisement push** + +Figure II.4 shows an example of pushing a personalized advertisement to the UE. DSN service routing system gathers user service usage information when a user accesses services through DSN. The service usage information is sent to the service analyzer which uses data mining algorithms to derive a user preference profile. Based on the user preference, DSN can push the user-specific advertisements to the UE. + +The advantage of personalized services is that DSN service routing provides an efficient way to gather service information and to apply user preferences to the service execution process. Compared to traditional service information gathering schemes, such as deep packet inspection (DPI), DSN provides a unified mechanism to identify services. Furthermore, DSN service routing can easily personalize the services by redirecting or adding parameters when routing the service requests. + +#### **II.1.6 Benefits** + +In these use cases, DSN service routing can provide the following benefits: + +- 1) DSN can provide the SP with professional platform support such as authentication, authorization and accounting (AAA). The SP does not need to invest or can greatly reduce their investment to develop and maintain these functions by themselves, allowing that SP to focus on its key service development. +- 2) DSN can optimize service provision with the service-related information collected by DSN service routing system. For example, DSN can collect the user location and easily choose the best application server. Users can get better service quality of experience (QoE) so that it will greatly promote the competition capability of the SP. +- 3) For the newly started SPs, it is hard to provide complicated and sophisticated mechanisms for load balancing, optimization, etc. By the help of DSN service routing, a growing SP can easily fulfil these service optimization functions so as to focus on their key service development and release their service in the shortest time. This scenario is especially valuable for the SPs in their initial stage of development. + +### **II.2 Service interconnection** + +SPs may need to connect to one another. Figure II.5 shows a use case where SPs connect to others SPs in order to provide more versatile service to their users. + +In this case, SP A, alone, provides a travel map and tour guide service. To enhance their user experience, ticket booking and hotel booking services are also necessary; however, SP A cannot provide these services by itself. So SP A chooses to collaborate with SP B and SP C, which are ticket and hotel booking service providers. + +![Figure II.5 – Service interconnection diagram. The diagram shows an 'Application domain' at the top with four service providers: Service provider D (with a copyright icon), Service provider C (with a 'Ticket' icon), Service provider B (with a 'HOTEL' icon), and Service provider A (with a map icon). Below this is the 'DSN core domain' containing three 'Core node' boxes connected in a ring. To the left is a 'Service directory' box containing a 'Service directory' box. A 'UE' (User Equipment) is shown on the right. Arrows indicate connections: arrow '1' goes from the UE to the rightmost Core node, and from that Core node to Service provider A; arrow '2' goes from the rightmost Core node to Service providers B and C.](c914f51f4427bc672dd0526cfc90ebe9_img.jpg) + +Y.2085(16)\_FII.5 + +Figure II.5 – Service interconnection diagram. The diagram shows an 'Application domain' at the top with four service providers: Service provider D (with a copyright icon), Service provider C (with a 'Ticket' icon), Service provider B (with a 'HOTEL' icon), and Service provider A (with a map icon). Below this is the 'DSN core domain' containing three 'Core node' boxes connected in a ring. To the left is a 'Service directory' box containing a 'Service directory' box. A 'UE' (User Equipment) is shown on the right. Arrows indicate connections: arrow '1' goes from the UE to the rightmost Core node, and from that Core node to Service provider A; arrow '2' goes from the rightmost Core node to Service providers B and C. + +**Figure II.5 – Service interconnection** + +As a precondition, SP A, SP B, and SP C sign separate contracts with DSN rather than contracting with one another. It could work in the following steps: + +- 1) When the UE accesses SP A, the user wants to download a tour map and guide from SP A. In addition, the user also wants to book a hotel and a plane ticket through just one service access to save time and for convenience. +- 2) Through DSN service routing, SP A can access SP B and SP C and get the hotel and plane ticket booking services. +- 3) Finally, SP A provides these services to the UE. + +#### **Benefits** + +In this case, DSN service routing can simplify the business contract relationship between SPs and enhance the collaboration efficiency between SPs. + +Especially for the newly started SP, it may need many partners to develop its service. Through DSN, it will be easier to achieve a wider partnership so as to quickly enhance a SP's service competition capability. + +### **II.3 Service store use case** + +DSN service routing system works as the service publication platform for the SP. Services provided by different SPs can be registered and published through this platform. Since there are a large numbers of subscribers of the carrier, this will greatly increase the possibility that the services will be visited by more users. For the DSN subscribers, they can also more easily find and request their preferred services through this system. + +![Figure II.6 – Service publication platform diagram. The diagram shows a Service provider A (containing three application servers) connected to a Service directory. The Service directory is connected to a DSN core domain (containing three core nodes). A UE (User Equipment) is connected to the DSN core domain. Arrows indicate the flow of information: 1) Service provider A to Service directory; 2) Service directory to DSN core domain; 3) DSN core domain to UE. The Service directory is labeled 'Service directory' and 'Service directory'. The DSN core domain is labeled 'DSN core domain' and contains three 'Core node' boxes. The UE is labeled 'UE'. The diagram is labeled 'Y.2085(16)_F11.6'.](c5452f95f3b28f1bfe29e84fbc2e1267_img.jpg) + +Figure II.6 – Service publication platform diagram. The diagram shows a Service provider A (containing three application servers) connected to a Service directory. The Service directory is connected to a DSN core domain (containing three core nodes). A UE (User Equipment) is connected to the DSN core domain. Arrows indicate the flow of information: 1) Service provider A to Service directory; 2) Service directory to DSN core domain; 3) DSN core domain to UE. The Service directory is labeled 'Service directory' and 'Service directory'. The DSN core domain is labeled 'DSN core domain' and contains three 'Core node' boxes. The UE is labeled 'UE'. The diagram is labeled 'Y.2085(16)\_F11.6'. + +**Figure II.6 – Service publication platform** + +In this case, SP A is a newly-founded map service provider. To let more users become acquainted with and access its service, SP A chooses to collaborate with a DSN provider to publish its service. + +The following steps show how this works: + +- 1) SP A connects with service directory and requests to store service related information into DSN. In order to guarantee the security of DSN, service directory works as an agent for the SP to avoid the SP directly accessing the distributed hash table (DHT) overlay. Service directory will allocate service ID for this service, which is a hash ID and uniquely refers to this service. +- 2) Service directory connects to the DSN core node. Based on the DHT algorithm, the service information data will be stored in the DSN responsible core node. This information can include e.g., service name, service ID, application server's location, workload, charging policy. +- 3) When the UE wants to use a map service, it connects to the service directory and checks the service in the map service category. The UE can easily find the map service provided by SP A. Once the UE selects the service, service directory will send the service ID to the UE. In this case, service directory works as the portal for the UE to query the service. + +#### Benefits + +By utilizing the subscriber resource of the carrier, the service would be discovered and accepted by many more users. Excessive advertisement expenditures bring challenges to the SPs, and this will significantly lower the advertising cost for the SP, especially for those growing SPs. Furthermore, it also helps users and third-party mashup service providers to find services. To the DSN operator, they will glean more dividends as more services are published in the platform. + +# Appendix III + +## An illustration of service profile's structure + +(This appendix does not form an integral part of this Recommendation.) + +The service profile is the data structure that presents the service related information. An example is shown below: + +![Diagram showing a Service profile table at the top, connected by lines to three Application server data tables below. The Service profile table has fields: Service Name, Service ID, Service Provider, App server list, Service type, SLA, Charging Policy, and ... The three Application server data tables (1, 2, and 3) each have fields: Service Name, Service ID, Service type, SLA, Server No., Server type, IP address, load maximum, load status, location, and ...](e354b57563dae469c00b412b2abdf765_img.jpg) + +Service profile + +| | | +|------------------|---------------| +| Service Name | "WORLD EARTH" | +| Service ID | 105973 | +| Service Provider | SP1 | +| App server list | | +| Service type | map | +| SLA | 1 | +| Charging Policy | ... | +| ... | ... | + + + +| | | +|--------------|----------------| +| Service Name | "WORLD EARTH" | +| Service ID | 105973 | +| Service type | map | +| SLA | 1 | +| Server No. | 000001 | +| Server type | Storage Server | +| IP address | 100.0.0.100 | +| load maximum | 100 | +| load status | 45 | +| location | ... | +| ... | ... | + +| | | +|--------------|---------------| +| Service Name | "WORLD EARTH" | +| Service ID | 105973 | +| Service type | map | +| SLA | 1 | +| Server No. | 000002 | +| Server type | Web Server | +| IP address | 100.0.0.101 | +| load maximum | 100 | +| load status | 30 | +| location | ... | +| ... | ... | + +| | | +|--------------|---------------| +| Service Name | "WORLD EARTH" | +| Service ID | 105973 | +| Service type | map | +| SLA | 1 | +| Server No. | 000003 | +| Server type | Web Server | +| IP address | 100.0.0.102 | +| load maximum | 80 | +| load status | 60 | +| location | ... | +| ... | ... | + +Application server 1 data                      Application server 2 data                      Application server 3 data + +Diagram showing a Service profile table at the top, connected by lines to three Application server data tables below. The Service profile table has fields: Service Name, Service ID, Service Provider, App server list, Service type, SLA, Charging Policy, and ... The three Application server data tables (1, 2, and 3) each have fields: Service Name, Service ID, Service type, SLA, Server No., Server type, IP address, load maximum, load status, location, and ... + +**Figure III.1 – Example of service profile** + +As shown in Figure III.1, the service profile is comprised of many attributes, e.g., service name, service ID, service provider, application server list, service type, service level agreement (SLA), charging policy. The service profile is generated while the AS initiates the registration procedures to the SRF. The SRF assigns a service ID to the service using DHT algorithms, and configures the attributes of the service profile. Then the profile will be forwarded to the control node that is responsible to keep it according to DHT. + +An operating service is supported by many different kinds of application servers, there is an attribute 'App servers list' in the service profile to demonstrate the application servers of the service. The application server data shows the attributes of the application servers, e.g., service name, service ID, service type, SLA, server no., server type, control node, IP address, load capability, load status, location. + +The service profile is the management information of the services in DSN. It is used in the flows of service subscription, service access and the service related scenarios. It can also be used to select the optimal server to serve the users by determining the location and load of the available application servers. + +# Bibliography + +- [b-ITU-T Y.2012] Recommendation ITU-T Y.2012 (2010), *Functional requirements and architecture of next generation networks*. +- [b-ITU-T Y.2206] Recommendation ITU-T Y.2206 (2010), *Requirements for distributed service networking capabilities*. +- [b-ITU-T Y Suppl.10] ITU-T Y-series Recommendations – Supplement 10 (2010), *ITU-T Y.2000-series – Supplement on distributed service network (DSN) use cases*. + + + +# SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Terminals and subjective and objective assessment methods | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/Y/T-REC-Y.2112-200706-I_PDF-E/042733dc5e8e7f5f30b60adba3266cde_img.jpg b/marked/Y/T-REC-Y.2112-200706-I_PDF-E/042733dc5e8e7f5f30b60adba3266cde_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..65eb6989b3522c0d117d5b2f123e3df133961083 --- /dev/null +++ b/marked/Y/T-REC-Y.2112-200706-I_PDF-E/042733dc5e8e7f5f30b60adba3266cde_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:cca1c3a1de9565174d57f4d96aee920a842d6998155ff4a15aeb601a85bb0d6e +size 64579 diff --git a/marked/Y/T-REC-Y.2112-200706-I_PDF-E/26d664119ad25250780f554633444e54_img.jpg b/marked/Y/T-REC-Y.2112-200706-I_PDF-E/26d664119ad25250780f554633444e54_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..e67e97579430916d60522294366eab10682d85ef --- /dev/null +++ b/marked/Y/T-REC-Y.2112-200706-I_PDF-E/26d664119ad25250780f554633444e54_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:ff5098c514e1dd6dc4e3ef5fab7133671ee6d90ac7b4c854973b5a1bc4e365d7 +size 89981 diff --git a/marked/Y/T-REC-Y.2112-200706-I_PDF-E/2b3a967f6ce4f23649be995a353e39f8_img.jpg b/marked/Y/T-REC-Y.2112-200706-I_PDF-E/2b3a967f6ce4f23649be995a353e39f8_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..f36df7c7bbb7575f526a71f99e0759d24839407b --- /dev/null +++ b/marked/Y/T-REC-Y.2112-200706-I_PDF-E/2b3a967f6ce4f23649be995a353e39f8_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:cdefba860b4c1614ccb67bab130e2ac2db644285da87b37b72c63a8e71bdf1e0 +size 35661 diff --git a/marked/Y/T-REC-Y.2112-200706-I_PDF-E/5132b3a97ac70fe4765c1e07e66b72b3_img.jpg b/marked/Y/T-REC-Y.2112-200706-I_PDF-E/5132b3a97ac70fe4765c1e07e66b72b3_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..b1dfa6c696953812273b55f8b9279fbd0b5a1b33 --- /dev/null +++ b/marked/Y/T-REC-Y.2112-200706-I_PDF-E/5132b3a97ac70fe4765c1e07e66b72b3_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:185cef9b778f4ded9da273744b8798744fb98499a60de5100c33ac119db1e1cb +size 85150 diff --git a/marked/Y/T-REC-Y.2112-200706-I_PDF-E/5445597cceefaca1ac89e710fe339325_img.jpg b/marked/Y/T-REC-Y.2112-200706-I_PDF-E/5445597cceefaca1ac89e710fe339325_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..9c0440c93a22d60f93bb06a280125a4997164a8f --- /dev/null +++ b/marked/Y/T-REC-Y.2112-200706-I_PDF-E/5445597cceefaca1ac89e710fe339325_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:482919d8510b51cdb826c80fa4274a00daa0c1668eca08581bba20d700124ebe +size 30138 diff --git a/marked/Y/T-REC-Y.2112-200706-I_PDF-E/5a4e62bead259c258d069fd3663ea670_img.jpg b/marked/Y/T-REC-Y.2112-200706-I_PDF-E/5a4e62bead259c258d069fd3663ea670_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..aee0659f260ffd01e8345d07e7fdce7c66229093 --- /dev/null +++ b/marked/Y/T-REC-Y.2112-200706-I_PDF-E/5a4e62bead259c258d069fd3663ea670_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:392aef51bfbf9307b0aab26a7ca440ac27dcf6653ae6c123f9a7678073234b7d +size 37528 diff --git a/marked/Y/T-REC-Y.2112-200706-I_PDF-E/8592a32c2fdf17c1e562f0ba6b7e8e1a_img.jpg b/marked/Y/T-REC-Y.2112-200706-I_PDF-E/8592a32c2fdf17c1e562f0ba6b7e8e1a_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..331e4f3e46a723421655fd3d1bd5f8be81ed53a1 --- /dev/null +++ b/marked/Y/T-REC-Y.2112-200706-I_PDF-E/8592a32c2fdf17c1e562f0ba6b7e8e1a_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:a577ee72a5475eca9ea1711abe39558ad3c01e3d684a7f49b09e85cd669d6180 +size 38109 diff --git a/marked/Y/T-REC-Y.2112-200706-I_PDF-E/a3dc41dc3df86ea68d266af2bf95cf5b_img.jpg b/marked/Y/T-REC-Y.2112-200706-I_PDF-E/a3dc41dc3df86ea68d266af2bf95cf5b_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..36cf51f8ba07e44aa7a4b009f3ba08eb2b570b1c --- /dev/null +++ b/marked/Y/T-REC-Y.2112-200706-I_PDF-E/a3dc41dc3df86ea68d266af2bf95cf5b_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:11780faeee75ba39ab4ed9de67a9e67abec0d9ba3068ebec661dea70c16e29d3 +size 4338 diff --git a/marked/Y/T-REC-Y.2112-200706-I_PDF-E/a734898ce18e972938949637c32a34f4_img.jpg b/marked/Y/T-REC-Y.2112-200706-I_PDF-E/a734898ce18e972938949637c32a34f4_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..da693912f1c0685761453d997f13307c53e49b47 --- /dev/null +++ b/marked/Y/T-REC-Y.2112-200706-I_PDF-E/a734898ce18e972938949637c32a34f4_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:8fb70c51544139211fb96df598735692a4a3ab54b501dc66192c0b7b7465cf7f +size 27613 diff --git a/marked/Y/T-REC-Y.2112-200706-I_PDF-E/b8661c6c54f72ecc7ff6cb05e47b2891_img.jpg b/marked/Y/T-REC-Y.2112-200706-I_PDF-E/b8661c6c54f72ecc7ff6cb05e47b2891_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..543c7a8be0446415ac93e52ad2ebac63d0656bbf --- /dev/null +++ b/marked/Y/T-REC-Y.2112-200706-I_PDF-E/b8661c6c54f72ecc7ff6cb05e47b2891_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:d058e926b32a93f79e7645a7d979c56ff59977fbade8618ba5aea79e37ecad96 +size 52619 diff --git a/marked/Y/T-REC-Y.2112-200706-I_PDF-E/cbdfdade780e677eb1c1aef3081ce9ef_img.jpg b/marked/Y/T-REC-Y.2112-200706-I_PDF-E/cbdfdade780e677eb1c1aef3081ce9ef_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..d737540ebddad41827de34aa1742c4d4f31128e9 --- /dev/null +++ b/marked/Y/T-REC-Y.2112-200706-I_PDF-E/cbdfdade780e677eb1c1aef3081ce9ef_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:763eecdfb036f84c133003b3e887d1c79bd9823c5119a6bb92dddf8388ec701c +size 86839 diff --git a/marked/Y/T-REC-Y.2112-200706-I_PDF-E/df82d77a0d2637cbf2da9ea920a554fa_img.jpg b/marked/Y/T-REC-Y.2112-200706-I_PDF-E/df82d77a0d2637cbf2da9ea920a554fa_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..5cd8798d0204e4b9da853f56265775e0ed2c8d56 --- /dev/null +++ b/marked/Y/T-REC-Y.2112-200706-I_PDF-E/df82d77a0d2637cbf2da9ea920a554fa_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:71acb3ba957607b4d6f0bd752f97fdbb66a3393c8d2e1daba41669073b1de976 +size 66878 diff --git a/marked/Y/T-REC-Y.2112-200706-I_PDF-E/dfe556fea00682b09a59427aaf72051c_img.jpg b/marked/Y/T-REC-Y.2112-200706-I_PDF-E/dfe556fea00682b09a59427aaf72051c_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..29c4d3a93bd9492f8b40dea242a5cbd5b0104689 --- /dev/null +++ b/marked/Y/T-REC-Y.2112-200706-I_PDF-E/dfe556fea00682b09a59427aaf72051c_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:f74824fe77f3256f2d52966f29d1bf8841db54cf10b3ee6b3b2f666f6b29d124 +size 61759 diff --git a/marked/Y/T-REC-Y.2112-200706-I_PDF-E/raw.md b/marked/Y/T-REC-Y.2112-200706-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..c0e8eeedcad9da3f90cac6363033ac61e4df658d --- /dev/null +++ b/marked/Y/T-REC-Y.2112-200706-I_PDF-E/raw.md @@ -0,0 +1,919 @@ + + +I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +# Y.2112 + +(06/2007) + +SERIES Y: GLOBAL INFORMATION +INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS +AND NEXT-GENERATION NETWORKS + +Next Generation Networks – Quality of Service and +performance + +# --- **A QoS control architecture for Ethernet-based IP access networks** + +ITU-T Recommendation Y.2112 + +## ITU-T Y-SERIES RECOMMENDATIONS GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS + +## GLOBAL INFORMATION INFRASTRUCTURE + +| | | +|-------------------------------------------|-------------| +| General | Y.100–Y.199 | +| Services, applications and middleware | Y.200–Y.299 | +| Network aspects | Y.300–Y.399 | +| Interfaces and protocols | Y.400–Y.499 | +| Numbering, addressing and naming | Y.500–Y.599 | +| Operation, administration and maintenance | Y.600–Y.699 | +| Security | Y.700–Y.799 | +| Performances | Y.800–Y.899 | + +## INTERNET PROTOCOL ASPECTS + +| | | +|--------------------------------------------------------------------|---------------| +| General | Y.1000–Y.1099 | +| Services and applications | Y.1100–Y.1199 | +| Architecture, access, network capabilities and resource management | Y.1200–Y.1299 | +| Transport | Y.1300–Y.1399 | +| Interworking | Y.1400–Y.1499 | +| Quality of service and network performance | Y.1500–Y.1599 | +| Signalling | Y.1600–Y.1699 | +| Operation, administration and maintenance | Y.1700–Y.1799 | +| Charging | Y.1800–Y.1899 | + +## NEXT GENERATION NETWORKS + +| | | +|-------------------------------------------------------------------|----------------------| +| Frameworks and functional architecture models | Y.2000–Y.2099 | +| Quality of Service and performance | Y.2100–Y.2199 | +| Service aspects: Service capabilities and service architecture | Y.2200–Y.2249 | +| Service aspects: Interoperability of services and networks in NGN | Y.2250–Y.2299 | +| Numbering, naming and addressing | Y.2300–Y.2399 | +| Network management | Y.2400–Y.2499 | +| Network control architectures and protocols | Y.2500–Y.2599 | +| Security | Y.2700–Y.2799 | +| Generalized mobility | Y.2800–Y.2899 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# **ITU-T Recommendation Y.2112** + +# **A QoS control architecture for Ethernet-based IP access networks** + +## **Summary** + +ITU-T Recommendation Y.2112 specifies a QoS control architecture for Ethernet-based IP access networks. By applying the resource and admission control functions specified in ITU-T Recommendation Y.2111 and Ethernet-specific QoS mechanisms, it enables dynamic QoS control in the access network for a variety of services, such as voice over IP, video on demand and bandwidth on demand. + +###### **Source** + +ITU-T Recommendation Y.2112 was approved on 13 June 2007 by ITU-T Study Group 13 (2005-2008) under the ITU-T Recommendation A.8 procedure. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2008 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## CONTENTS + +| | | Page | +|----|------------------------------------------------------------------|-------------| +| 1 | Scope ..... | 1 | +| 2 | References..... | 1 | +| 3 | Definitions ..... | 1 | +| | 3.1 Terms defined elsewhere..... | 1 | +| | 3.2 Terms defined in this Recommendation..... | 2 | +| 4 | Abbreviations and acronyms ..... | 2 | +| 5 | Conventions..... | 4 | +| 6 | Ethernet-based IP access network reference models..... | 4 | +| 7 | Requirements for support of dynamic QoS control..... | 5 | +| 8 | Functional architecture for support of dynamic QoS control ..... | 6 | +| | 8.1 Overview ..... | 6 | +| | 8.2 QoS mechanisms ..... | 7 | +| | 8.3 Resource and admission control function (RACF) ..... | 7 | +| | 8.4 Policy decision functional entity (PD-FE) ..... | 7 | +| | 8.5 Transport resource control functional entity (TRC-FE)..... | 7 | +| | 8.6 Transport functions..... | 8 | +| 9 | Reference point requirements ..... | 9 | +| | 9.1 Rs between SCF and PD-FE..... | 10 | +| | 9.2 Rt between PD-FE and TRC-FE ..... | 10 | +| | 9.3 Ru between PD-FE and NACF..... | 10 | +| | 9.4 Rw between PD-FE and PE-FE..... | 10 | +| | 9.5 Rc between TRC-FE and access network nodes ..... | 10 | +| | 9.6 Rn between TRC-FE and TRE-FE ..... | 10 | +| 10 | Procedures for support of dynamic QoS control ..... | 10 | +| | 10.1 Network topology and resource attributes collection..... | 11 | +| | 10.2 Resource allocation ..... | 11 | +| | 10.3 Resource modification..... | 12 | +| | 10.4 Resource release ..... | 12 | +| | 10.5 Failure handling..... | 12 | +| 11 | Deployment scenarios..... | 14 | +| 12 | Security considerations..... | 14 | +| | Appendix I – Ethernet-based IP access networks and QoS ..... | 15 | +| | Appendix II – Last-mile user access technology ..... | 17 | + +| | Page | +|-----------------------------------|-------------| +| Appendix III – Use cases ..... | 18 | +| III.1    Overview ..... | 18 | +| III.2    Voice over IP..... | 18 | +| III.3    Video on demand..... | 19 | +| III.4    Bandwidth on demand..... | 19 | +| Bibliography..... | 21 | + +# ITU-T Recommendation Y.2112 + +# A QoS control architecture for Ethernet-based IP access networks + +## 1 Scope + +This Recommendation specifies a quality of service (QoS) control architecture and requirements covering aspects, such as resource reservation, admission control and gate control, for Ethernet-based IP access networks. Based on the resource and admission control functions (RACF) as defined in [ITU-T Y.2111], this Recommendation provides details specific to Ethernet-based IP access networks. An Ethernet-based IP access network is an IP access network which comprises the Ethernet aggregation network, access nodes, and edge nodes, and may also include the IP aggregation network. + +In this Recommendation, the Ethernet aggregation network supports VLANs as defined in [b-IEEE 802.1Q] and [b-IEEE 802.1ad]. Note that the QoS mechanisms for the last mile user access segment are MAC technology-specific and as such are out of the scope of this Recommendation. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[ITU-T Y.1231] ITU-T Recommendation Y.1231 (2000), *IP access network architecture*. + +[ITU-T Y.2091] ITU-T Recommendation Y.2091 (2007), *Terms and definitions for Next Generation Networks*. + +[ITU-T Y.2111] ITU-T Recommendation Y.2111 (2006), *Resource and admission control functions in Next Generation Networks*. + +## 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 absolute QoS** [ITU-T Y.2111]: This term refers to a traffic delivery service with numerical bounds on some or all of the QoS parameters. These bounds may be physical limits, or enforced limits such as those encountered through mechanisms like rate policing. The bounds may result from designating a class of network performance objectives for packet transfer. + +**3.1.2 gate control** [ITU-T Y.2111]: The operation of opening or closing a gate. When a gate is open, the packets in the media flows are allowed to pass through; when a gate is closed, the packets in the media flows are not allowed to pass through. + +**3.1.3 IP access network** [ITU-T Y.1231]: An implementation comprising network entities to provide the required access capabilities between an "IP user" and an "IP service provider" for the provision of IP services. "IP user" and "IP service provider" are logical entities which terminate the IP layer and/or IP related functions, and may also include lower layer functions. + +**3.1.4 IP core network** [ITU-T Y.1231]: IP service provider's network, including one or more IP service providers. + +**3.1.5 media flow** [ITU-T Y.2111]: A unidirectional media stream, which is specified by two endpoint identifiers and bandwidth, as well as class of service, if needed. + +**3.1.6 relative QoS** [ITU-T Y.2111]: This term refers to a traffic delivery service without absolute bounds on the achieved bandwidth, packet delay or packet loss rates. It describes circumstances where certain classes of traffic are handled differently from other classes of traffic, and the classes achieve different levels of QoS. + +**3.1.7 session** [ITU-T Y.2091]: A temporary telecommunication relationship among a group of objects in the service stratum that are assigned to collectively fulfil a task for a period of time. A session has a state that may change during its lifetime. Session-based telecommunications may, but need not be, assisted by intermediaries (see mediated services). Session-based telecommunications can be one-to-one, one-to-many, many-to-one, or many-to-many. + +### **3.2 Terms defined in this Recommendation** + +This Recommendation defines the following terms: + +**3.2.1 edge router**: An edge router is a router that operates at the edge of access network and aggregates IP datagrams from access network into the core network. + +**3.2.2 Ethernet-based IP access network**: An IP access network that comprises the Ethernet aggregation network, access nodes (such as DSLAM), and edge nodes (such as BRAS) and may also include the IP aggregation network. Edge nodes are typically IP capable. Access nodes may be IP capable. + +**3.2.3 IP flow**: A sequence of packets sent from a particular source to a particular destination, to which common routing is applied. + +**3.2.4 last mile user access**: The portion of the access network between the CPE and the access node. + +NOTE – If using IPv4, a flow is identified by the IPv4 5-tuple which includes source/destination IP addresses, protocol ID and source/destination port numbers. If using IPv6, a flow is identified by the IPv6 3-tuple which includes source/destination IP addresses and flow label. + +## **4 Abbreviations and acronyms** + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|------|----------------------------------------------| +| AAA | Authentication, Authorization and Accounting | +| AN | Access Node | +| APP | Application Layer | +| BE | Best Effort | +| BoD | Bandwidth on Demand | +| BRAS | Broadband Remote Access Server | +| CDN | Content Delivery Network | +| CPE | Customer Premises Equipment | + +| | | +|--------|----------------------------------------------| +| CPN | Customer Premises Network | +| DHCP | Dynamic Host Configuration Protocol | +| DSCP | Differentiated Services Code Point | +| DSL | Digital Subscriber Line | +| DSLAM | Digital Subscriber Line Access Multiplexer | +| DST | Destination | +| EAP | Extensible Authentication Protocol | +| EN | Edge Node | +| ER | Edge Router | +| EXP | Experimental bits | +| GRE | Generic Routing Encapsulation | +| HTTP | HyperText Transfer Protocol | +| ID | Identifier | +| IMN | InterMediate Node | +| IP | Internet Protocol | +| L2TP | Layer 2 Tunnelling Protocol | +| LLDP | Link Layer Discovery Protocol | +| LSP | Label Switched Path | +| MAC | Media Access Control | +| MPLS | Multi-Protocol Label Switching | +| NACF | Network Attachment Control Function | +| PD-FE | Policy Decision Functional Entity | +| PE-FE | Policy Enforcement Functional Entity | +| PHB | Per Hop Behaviour | +| PHY | Physical Layer | +| PPP | Point-to-Point Protocol | +| QoS | Quality of Service | +| RACF | Resource and Admission Control Function | +| RSVP | Resource ReSerVation Protocol | +| SCF | Service Control Function | +| SLA | Service Level Agreement | +| SNMP | Simple Network Management Protocol | +| SRC | Source | +| STP | Spanning Tree Protocol | +| S-VLAN | Service Virtual Local Area Network | +| TCP | Transmission Control Protocol | +| TRC-FE | Transport Resource Control Functional Entity | + +| | | +|--------|--------------------------------------------------| +| TRE-FE | Transport Resource Enforcement Functional Entity | +| UDP | User Datagram Protocol | +| UMTS | Universal Mobile Telecommunications System | +| VoD | Video on Demand | +| VoIP | Voice over IP | +| VPN | Virtual Private Network | +| WLAN | Wireless Local Area Network | + +## 5 Conventions + +This clause is intentionally left blank. + +## 6 Ethernet-based IP access network reference models + +This Recommendation assumes that the Ethernet-based IP access network is comprised of: a last mile user access facility, an Ethernet aggregation network, an access node that may be IP capable (e.g., DSLAM), an edge node that is IP capable (e.g., BRAS) and may also include the IP aggregation network. See Figure 1 below. It also assumes that an Ethernet-based IP access network may support several different types of the last mile user access technologies. For example, an Ethernet-based IP DSLAM may support LAN/xDSL/WLAN user access, and different types of access nodes may be deployed and aggregated to the same BRAS. Additionally, it assumes that the BRAS may serve as an edge router; in that case there is no IP level aggregation performed. In this Recommendation, the edge node (EN) acts as the egress of upstream traffic that connects the IP access network to the core network. It may represent either a BRAS or ER. + +![Figure 1: Generic architectural and topological model of Ethernet-based IP access network. The diagram shows a flow from left to right. On the far left, a dashed box labeled 'CPN' contains three 'TE' (Terminal Entity) boxes connected to an 'IP router' and a 'Modem', which together form a 'Home gateway'. A line labeled 'Last mile user access' connects the 'Home gateway' to an 'Access node'. The 'Access node' is connected to an 'Ethernet level aggregation network' (represented by an oval). This is followed by a 'BRAS' (Broadband Remote Access Server) box, then an 'IP level aggregation network' (represented by an oval), and finally an 'Edge router' box. These components (Access node, Ethernet level aggregation network, BRAS, IP level aggregation network, and Edge router) are all contained within a larger box labeled 'Ethernet-based IP access network'. To the right of this box is the 'IP core network', which contains two ovals labeled 'Network operator 1' and 'Network operator N' connected by a dashed line. The label 'Y.2112(07)_F.01' is located below the 'Ethernet-based IP access network' box.](b8661c6c54f72ecc7ff6cb05e47b2891_img.jpg) + +Figure 1: Generic architectural and topological model of Ethernet-based IP access network. The diagram shows a flow from left to right. On the far left, a dashed box labeled 'CPN' contains three 'TE' (Terminal Entity) boxes connected to an 'IP router' and a 'Modem', which together form a 'Home gateway'. A line labeled 'Last mile user access' connects the 'Home gateway' to an 'Access node'. The 'Access node' is connected to an 'Ethernet level aggregation network' (represented by an oval). This is followed by a 'BRAS' (Broadband Remote Access Server) box, then an 'IP level aggregation network' (represented by an oval), and finally an 'Edge router' box. These components (Access node, Ethernet level aggregation network, BRAS, IP level aggregation network, and Edge router) are all contained within a larger box labeled 'Ethernet-based IP access network'. To the right of this box is the 'IP core network', which contains two ovals labeled 'Network operator 1' and 'Network operator N' connected by a dashed line. The label 'Y.2112(07)\_F.01' is located below the 'Ethernet-based IP access network' box. + +**Figure 1 – Generic architectural and topological model of Ethernet-based IP access network** + +Generally, L2 or L3 switches are used for Ethernet level traffic aggregation per subscriber, and L3 switches or IP routers are used for IP level aggregation per QoS class or service type. + +Home gateways may consist of modems and an IP router; however, either element can be optional depending on the type of last mile user access technology. + +The access node terminates the last mile access facility on the network side, and physically may be a single device or a chain of subtended devices. It may be located at a central office or a remote site or both. It must have one or more Ethernet uplink interfaces when residing in an Ethernet-based IP access network. + +The broadband remote access server (BRAS) terminates the user access link (e.g., PPP, EAP [b-IETF RFC 2284], VLAN), performs network access control, and aggregates the user traffic into a VLAN, VPN, or tunnel as with native IP traffic. It must have one or more Ethernet downlink interfaces and be able to terminate its Ethernet layer when residing in an Ethernet-based IP access network. The BRAS also provides: policy management, AAA and DHCP interfaces; user access control, and assigns user IP addresses. + +The edge router (ER) is an egress IP router which connects an IP access network to one or multiple IP service providers in an IP core network. An edge router may aggregate IP traffic from one or multiple BRAS. It may also contain NAT and/or firewall elements. + +Figure 2 uses PPP as an example to illustrate the protocol layered model of an Ethernet-based IP access network. + +![Figure 2: An example of protocol layered model of an Ethernet-based IP access network. The diagram shows a sequence of network elements: CPE, AN, BRAS, Router, and ER. Each element is represented by a box showing its protocol layers. CPE has IP, PPP, ETH, and PHY layers. AN has two parallel boxes, each with ETH and PHY layers. BRAS has IP, PPP, ETH, and PHY layers. Router has two parallel boxes, each with IP, ETH, and PHY layers. ER has two parallel boxes, each with IP, ETH, and PHY layers. Horizontal lines connect the PHY layers of adjacent elements, representing the physical link.](5a4e62bead259c258d069fd3663ea670_img.jpg) + +Y.2112(07)\_F.02 + +Figure 2: An example of protocol layered model of an Ethernet-based IP access network. The diagram shows a sequence of network elements: CPE, AN, BRAS, Router, and ER. Each element is represented by a box showing its protocol layers. CPE has IP, PPP, ETH, and PHY layers. AN has two parallel boxes, each with ETH and PHY layers. BRAS has IP, PPP, ETH, and PHY layers. Router has two parallel boxes, each with IP, ETH, and PHY layers. ER has two parallel boxes, each with IP, ETH, and PHY layers. Horizontal lines connect the PHY layers of adjacent elements, representing the physical link. + +**Figure 2 – An example of protocol layered model of an Ethernet-based IP access network** + +## 7 Requirements for support of dynamic QoS control + +Ethernet-based IP access networks conforming to this Recommendation are required to be able to: + +- 1) Support dynamic QoS control for a variety of services, such as voice over IP, video on demand and bandwidth on demand. The QoS control procedure may be triggered by application layer protocols such as SIP, H.323, HTTP, etc. +- 2) Support QoS differentiation based on service types and users. +- 3) Support absolute QoS and relative QoS. +- 4) Support admission control on a per flow basis. The service layer informs the transport layer of the flow description (IPv4 5-tuple or IPv6 3-tuple). The service layers determine the QoS requirements for a media flow based on the service type, service level agreement (SLA) or user explicit QoS request and inform the requirements to the transport layer. + +It is desirable for Ethernet-based IP access networks conforming to this Recommendation to also be able to: + +- 5) Support admission control for media flows with QoS requirements based on user profiles, SLA, operator policy rules and network resource availability. The traditional policy control framework [b-IETF RFC 2475] only makes allowance for admission control at per-user or per-network level based on SLA and policy rules. +- 6) Collect the network topology and resource information by static or dynamic means. + +## 8 Functional architecture for support of dynamic QoS control + +Figure 3 illustrates a reference architecture for support of dynamic QoS control over Ethernet-based IP access networks. + +![Figure 3: Functional architecture for support of dynamic QoS control.](042733dc5e8e7f5f30b60adba3266cde_img.jpg) + +``` + + graph TD + SCF[Service control functions] -- Rs --- RACF + subgraph Service_Stratum [Service stratum] + end + subgraph Transport_Stratum [Transport stratum] + NACF[Network attachment control functions] -- Ru --- RACF + subgraph RACF_Box [RACF] + PDFE[PD-FE] -- Rt --- TRCFE[TRC-FE] + end + CPE[CPE] --- AN + subgraph Ethernet_Access [Ethernet-based IP access network] + subgraph AN_Box [AN] + PEFE1[PE-FE] + TREFE1[TRE-FE] + end + IMNs[IMNs] + subgraph EN_Box [EN] + PEFE2[PE-FE] + TREFE2[TRE-FE] + end + AN_Box --- IMNs --- EN_Box + end + EN_Box --- Core[Core network] + end + RACF -- Rw --- AN_Box + RACF -- Rn --- IMNs + RACF -- Rc --- IMNs + RACF -- Rn --- EN_Box + RACF -- Rw --- EN_Box + +``` + +The diagram depicts the functional architecture for dynamic QoS control. At the top, 'Service control functions' reside in the 'Service stratum'. Below a dashed line is the 'Transport stratum' containing 'Network attachment control functions' and the 'RACF' (Resource and Admission Control Functions). The RACF contains 'PD-FE' and 'TRC-FE' connected by reference point 'Rt'. The RACF connects to 'Service control functions' via 'Rs' and to 'Network attachment control functions' via 'Ru'. Below the RACF is the 'Ethernet-based IP access network' containing an Access Node (AN), Intermediate Nodes (IMNs), and an Edge Node (EN). The AN and EN both contain 'PE-FE' and 'TRE-FE' functional entities. The RACF connects to these nodes via reference points 'Rw', 'Rn', and 'Rc'. On the periphery, 'CPE' (Customer Premises Equipment) connects to the AN, and the EN connects to the 'Core network'. + +Figure 3: Functional architecture for support of dynamic QoS control. + +**Figure 3 – Functional architecture for support of dynamic QoS control** + +### 8.1 Overview + +The reference architecture allows different applications over various types of access networks which may use different transport technologies. + +The service control functions (SCF) deals with service requests. SCF determines the QoS requirements (including bandwidth and QoS classes) of each media flow by inspecting the type of service or user explicit QoS request in application layer signalling (e.g., in SDP). It then sends the resource request to the resource and admission control functions (RACF) via the Rs reference point. SCF is service specific and may be realized in any service subsystems offering services that require the control of transport resources, e.g., IP multimedia subsystem. SCF may be implemented as a stand-alone box or as a function module embedded in other equipment. + +RACF deals with resource requests containing specific QoS requirements for IP flows. RACF receives the QoS request from SCF and maps the service QoS parameters and priority to transport QoS parameters and priority. RACF makes admission control, path selection and resource allocation for the resource request of a media flow based on user profile, SLA, operator policy rules and network resource availability. Note that path selection in RACF means the selection of ingress and egress points within a single domain to satisfy QoS resource requirements rather than network routing. If the QoS request from SCF is admitted, RACF installs the QoS admission decision to AN/EN. RACF will maintain the network topology and resource status information when the resource status or topology changes. Generally, interface or network failure will cause topology and resource status change. RACF may be implemented as stand-alone equipment or as a function module embedded in other equipment. + +Transport functions of the Ethernet-based IP access network include three types of network nodes: access node (AN), edge node (EN) and intermediate node (IMN). Note that IMNs represent the network elements located in Ethernet aggregation network in the IP access network (see Figure 1). + +Customer premises equipment (CPE) refers to all the devices in a CPN. It generally is a customer terminal, e.g., SIP terminal. It is assumed that CPN should be able to forward customer packets without congestion, and ensure the QoS of the customer flows within the CPN. + +### **8.2 QoS mechanisms** + +#### **8.2.1 Support of relative QoS** + +For support of relative QoS, RACF enforces its admission control decision at the aggregate or flow level via the Rn or Rw reference point. AN and EN are required to classify, mark, police, shape, queue and schedule the traffic entering and leaving the access network according to the QoS configuration. IMN forwards the packets according to the priority marked by AN/EN. It is desirable that the requirements of the Rn, Rw and Rc reference points conform to the policy control framework [b-IETF RFC 2475]. + +#### **8.2.2 Support of absolute QoS** + +For support of absolute QoS, it is required to avoid bandwidth contention and traffic congestion within the network in addition to perform bandwidth policing and traffic shaping at the edge of the network. There is one way to achieve this: + +Give RACF the full awareness of a logical tree-based network topology and the link resource attributes of the whole access network. RACF makes admission control based on this awareness to ensure that sufficient resources are available within the network for the current media flows with absolute QoS requirements. The logical tree-based network topology can be achieved by enabling spanning tree protocol (STP) or static configuration (e.g., configuring VLANs) or retrieving the topology and resource status information from a network management system. + +If the AN is a Layer 2 device without IP capability, RACF is required to perform gate control only at EN via the Rw reference point. If the AN is IP capable, RACF is required to perform gate control at both AN and EN via the Rw reference point. + +### **8.3 Resource and admission control function (RACF)** + +As defined in [ITU-T Y.2111], RACF consists of two functional entities: policy decision functional entity (PD-FE) and transport resource control functional entity (TRC-FE). + +### **8.4 Policy decision functional entity (PD-FE)** + +The PD-FE handles the QoS resource requests received from the SCF via the Rs reference point or from PE-FE via the Rw reference point. + +### **8.5 Transport resource control functional entity (TRC-FE)** + +The TRC-FE is responsible for transport technology dependent resource control. The basic functions of TRC-FE are described in [ITU-T Y.2111]. A TRC-FE over an Ethernet-based IP access network contains the following functions: + +- Network topology maintenance: In an IEEE 802.1Q/802.1ad enabled Ethernet, most nodes handle packets using MAC bridging or virtual bridging based on MAC addresses and VLAN IDs. Generally, the active network topology is loop-free and is fully connected by means of spanning tree protocol [b-IEEE 802.1Q]. TRC-FE may collect the topology using SNMP or by static configuration. +- Network resource maintenance: This function collects and maintains the transport resource status information via the Rc reference point. + +- QoS mapping-technology dependent: This function maps the network QoS parameters and classes received from the PD-FE via the Rt reference point to transport (technology dependent) QoS parameters and classes based on specific transport policy rules, and accommodating the diversity of transport technologies. In the case of Ethernet-based IP access networks, TRC-FE maps the network QoS parameters and classes into IEEE 802.1Q/802.1ad VLAN priorities and traffic classes (e.g., the mapping of [b-ITU-T Y.1541] QoS classes and VLAN priority/traffic classes). Note that, according to [b-IEEE 802.1Q], a given port has one or more queues and each queue corresponds to a distinct traffic class. Each frame is mapped to a traffic class using the traffic class table for the port and the frame's priority. Up to eight traffic classes may be supported, allowing separate queues for each priority. +- Technology dependent decision point: This function receives and responds to the QoS resource request from PD-FE via the Rt reference point. +- Control of transport resource enforcement: This function controls TRE-FE to enforce the transport resource policy rules at the technology-dependent aggregate level via Rn reference point. The transport policy rules may include bandwidth allocation/rate limiting, marking/remarking, shaping/policing, etc. It should be noted that all these policy rules should be based on IEEE 802.1Q/802.1ad VLAN. + +### 8.6 Transport functions + +Transport functions of the Ethernet-based IP access network include three types of network nodes: access node (AN), edge node (EN) and intermediate node (IMN). PE-FE or TRE-FE or both may be located in AN and EN. PE-FE and TRE-FE are defined in [ITU-T Y.2111]. + +#### 8.6.1 Access node (AN) + +The AN directly connects to the CPN and terminates the first/last mile link signals such as Ethernet, xDSL, cable, GPON/EPON, etc. Generally, it is a Layer 2 device which may have IP awareness. PE-FE located in AN enforces the network policy rules at per flow level and TRE-FE located in AN enforces the transport resource policy rules at per aggregate level. QoS mechanisms of AN include buffer management, queuing and scheduling, packet filtering, traffic classification, marking, policing, and shaping. The PE-FE/TRE-FE located in AN performs QoS control functions at the flow level or aggregate level under the control of the RACF via the Rn or Rw reference points. + +##### 8.6.1.1 PE-FE located in AN + +If PE-FE is located in AN, it enforces the transport resource policy rules at flow level in the upstream direction. The functions of PE-FE include: + +- Opening and closing gate. +- Rate limiting and bandwidth allocation. +- Traffic classification and marking. +- Traffic policing and shaping. +- Mapping of IP-layer QoS information (e.g., DiffServ code point) onto IEEE 802.1Q/802.1ad VLAN priority/traffic class. +- Collecting and reporting resource usage information (e.g., start-time, end-time, octets of sent data). + +Note that PE-FE located in AN has only part of the PE-FE functions defined in [ITU-T Y.2111]. + +##### **8.6.1.2 TRE-FE located in AN** + +If TRE-FE is located in AN, it enforces the transport resource policy rules at aggregate level in upstream direction. The functions of TRE-FE include: + +- Rate limiting and bandwidth allocation. +- Traffic classification and marking. +- Traffic policing and shaping. +- Collecting and reporting resource usage information (e.g., start-time, end-time, octets of sent data). + +TRE-FE should be able to perform the above functions on a per aggregate level basis including user port (physical port or logical port), Ethertype, VLAN ID, and VLAN priority. + +#### **8.6.2 Intermediate node (IMN)** + +IMN refers to all the network nodes between EN and AN in an Ethernet-based IP access network. Generally, IMNs consist of Ethernet switches. + +The nodes within the Ethernet aggregation network are required to be S-VLAN bridges according to [b-IEEE 802.1ad] and are required to be configurable on a per S-VLAN basis. An IMN contains the following functions: + +- Queuing and scheduling: The IMN must support at least 4 traffic classes for Ethernet frames, and configurable mapping to these traffic classes from 8 possible VLAN priorities. It must support strict priority scheduling, and should be able to support weighted priority scheduling which provides support of mapping DiffServ PHBs to VLAN priorities. +- Collecting and reporting resource status information: The IMN must collect and report the resources status information including: + - 1) the physical ports resource status; + - 2) the S-VLAN ports resource status. + +#### **8.6.3 Edge node (EN)** + +EN acts as the egress of upstream traffic that connects the IP access network to the core network. It is a Layer 3 device with routing capabilities. A PE-FE is located in EN and performs QoS mechanisms dealing with the user traffic directly, including buffer management, queuing and scheduling, packet filtering, traffic classification, marking, policing, and shaping. As a key injection node for support of dynamic QoS control, the EN with PE-FE performs QoS control functions at flow level under the control of the RACF via the Rw reference point. A TRE-FE may be located in EN and enforces the transport resource policy rules at a per aggregate level. + +##### **8.6.3.1 PE-FE located in EN** + +PE-FE located in EN performs the same functions as defined in clause 8.6.1.1. Note that it enforces the transport resource policy rules in upstream and downstream directions if there is no PE-FE located in AN. + +##### **8.6.3.2 TRE-FE located in EN** + +TRE-FE located in EN performs the same functions as defined in clause 8.6.1.2. Note that it enforces the transport resource policy rules at aggregate level in downstream direction. + +## **9 Reference point requirements** + +This clause defines the reference point requirements for support of the dynamic QoS control. + +### **9.1 Rs between SCF and PD-FE** + +The Rs reference point is the same as defined in [ITU-T Y.2111]. + +### **9.2 Rt between PD-FE and TRC-FE** + +The Rt reference point is the same as defined in [ITU-T Y.2111]. + +### **9.3 Ru between PD-FE and NACF** + +The Ru reference point is the same as defined in [ITU-T Y.2111]. + +### **9.4 Rw between PD-FE and PE-FE** + +The Rw reference point is the same as defined in [ITU-T Y.2111]. + +### **9.5 Rc between TRC-FE and access network nodes** + +The TRC-FE interacts with the access network nodes through the Rc reference point. The main function of this reference point is to gather information on resource attributes (e.g., bandwidth) and network topology. + +Network topology and resource attributes collection is the basis for making flow route determination, admission control and resource allocation for support of dynamic QoS control. + +TRC-FEs conforming to this Recommendation are required to be able to: + +- Timely and accurately gather the link layer topology and resource attributes from transport elements via the Rc reference point. Note that the topology and resource information may be provisioned in the TRC-FE. +- Timely and accurately track the changes of the link layer topology and resource attributes via the Rc reference point. +- Timely and accurately track the changes of the topology and resource attributes of the logical network connections via the Rc reference point. +- Request notification of events (e.g., link or port failure) from a transport element to update the resource status information. + +It is desirable for TRC-FEs conforming to this Recommendation to also be able to: + +- Timely and accurately gather the topology and resource attributes of the logical network connections (e.g., S-VLAN) from transport elements via the Rc reference point. Note that the topology and resource information for the logical network connections may be provisioned in the TRC-FE. +- Timely and accurately gather the topology and resource attributes at the Ethernet traffic class level (e.g., 802.1p). +- Timely and accurately track the changes of the topology and resource attributes at the Ethernet traffic class level (e.g., 802.1p). + +The details of the Rc reference point are for further study. + +### **9.6 Rn between TRC-FE and TRE-FE** + +The Rn reference point is for further study. + +## **10 Procedures for support of dynamic QoS control** + +This clause defines the procedures that can be applied in the reference architecture for support of dynamic QoS control. + +### 10.1 Network topology and resource attributes collection + +Topology and resource attributes of the Ethernet-based IP access network can be obtained by means of static configuration or dynamic collection. In the case of dynamic collection, the information can be acquired from the MIBs of the network nodes via a defined protocol and then sorted together. The logical connection state is available in the VLAN MIB. The spanning tree state is available in the Bridge MIB. The link speed is available in the Interface MIB. The adjacent device connectivity is available in the LLDP MIB (link layer discovery protocol [b-IEEE 802.1AB]). The acquired network topology and resource attributes and the resource allocation status are stored in the network topology and resource status information, which is generally maintained on TRC-FE. Flow admission control, route determination and resource allocation are done on the basis of user profiles, SLAs, operator policy rules and network topology and resource status information. + +### 10.2 Resource allocation + +The procedure of resource allocation as illustrated in Figure 4 is the same as that defined in [ITU-T Y.2111]. + +![Sequence diagram illustrating the Resource allocation procedure between PE-FE, PD-FE, TRC-FE, and SCF.](df82d77a0d2637cbf2da9ea920a554fa_img.jpg) + +``` +sequenceDiagram + participant PE-FE + participant PD-FE + participant TRC-FE + participant SCF + + SCF->>SCF: 1. Trigger + SCF->>PD-FE: 2. Resource initiation request (reservation) + PD-FE->>PD-FE: 3. Policy decision (authorization) + PD-FE->>TRC-FE: 4. Resource initiation request/response (availability check) + TRC-FE-->>PD-FE: + PD-FE->>PD-FE: 5. Final admission decision (reservation and/or commitment) + PD-FE-->>PE-FE: 6. Resource initiation request (reservation/commitment) + PE-FE-->>PD-FE: 7. Resource initiation response + PD-FE->>SCF: 8. Resource initiation response +``` + +The diagram illustrates the resource allocation procedure involving four entities: PE-FE, PD-FE, TRC-FE, and SCF. The process begins with a '1. Trigger' at SCF. SCF sends a '2. Resource initiation request (reservation)' to PD-FE. PD-FE performs a '3. Policy decision (authorization)'. PD-FE then sends a '4. Resource initiation request/response (availability check)' to TRC-FE, which responds. PD-FE then performs a '5. Final admission decision (reservation and/or commitment)'. PD-FE sends a '6. Resource initiation request (reservation/commitment)' to PE-FE, which responds with '7. Resource initiation response'. Finally, PD-FE sends an '8. Resource initiation response' to SCF. + +Y.2112(07)\_F.04 + +Sequence diagram illustrating the Resource allocation procedure between PE-FE, PD-FE, TRC-FE, and SCF. + +**Figure 4 – Resource allocation procedure** + +### 10.3 Resource modification + +The procedure of resource modification as illustrated in Figure 5 is the same as that defined in [ITU-T Y.2111]. + +![Sequence diagram for Resource modification procedure (Figure 5).](dfe556fea00682b09a59427aaf72051c_img.jpg) + +``` +sequenceDiagram + participant PE-FE + participant PD-FE + participant TRC-FE + participant SCF + SCF->>SCF: 1. Trigger + SCF->>PD-FE: 2. Resource modification request (authorization/reservation/commitment) + PD-FE->>PD-FE: 3. Policy decision + PD-FE->>TRC-FE: 4. Resource modification (availability check) + PD-FE->>PD-FE: 5. Final admission decision + PD-FE-->>PE-FE: 6. Resource modification request + PE-FE-->>PD-FE: 7. Resource modification response + PD-FE->>SCF: 8. Resource modification response +``` + +Y.2112(07)\_F.05 + +Sequence diagram for Resource modification procedure (Figure 5). + +**Figure 5 – Resource modification procedure** + +### 10.4 Resource release + +The procedure of resource release as illustrated in Figure 6 is the same as that defined in [ITU-T Y.2111]. + +![Sequence diagram for Resource release procedure (Figure 6).](8592a32c2fdf17c1e562f0ba6b7e8e1a_img.jpg) + +``` +sequenceDiagram + participant PE-FE + participant PD-FE + participant TRC-FE + participant SCF + SCF->>SCF: 1. Trigger + SCF->>PD-FE: 2. Resource release request + PD-FE->>PE-FE: 3. Resource release request + PE-FE->>PD-FE: 4. Resource release response + PD-FE->>TRC-FE: 5. Resource release request/response + TRC-FE->>SCF: 6. Resource release response +``` + +Y.2112(07)\_F.06 + +Sequence diagram for Resource release procedure (Figure 6). + +**Figure 6 – Resource release procedure** + +### 10.5 Failure handling + +This clause introduces the procedure of resource release due to interface failure or network failure. AN/EN will trigger the resource release procedure if AN/EN is not able to provide the reserved QoS resource any longer for the media flow due to its interface failure; TRC-FE will trigger resource release procedure if TRC-FE perceives the network is not able to provide the reserved QoS resource any longer for the media flow due to network failure. + +#### 10.5.1 TRE-FE-indicated resource release procedure + +As shown in Figure 7, TRE-FE should release all resources related to the failed interface and send "Resource Unavailable Indication" to TRC-FE. The resources related to the failed interface are marked as unavailable in network topology and resource information. TRC-FE sends a Resource Notification to the PD-FE on its own initiative. PD-FE forwards "Resource Notification" to SCF if the reserved QoS resource is relevant with an SCF session. A message containing flows description is sent from TRC-FE to PE-FE, and then the PE-FE removes the identifications and classifications of the flows including the identifications and classifications of the opposite direction flows for the bidirectional flows. + +![Sequence diagram for TRE-FE-indicated resource release procedure](2b3a967f6ce4f23649be995a353e39f8_img.jpg) + +``` +sequenceDiagram + participant TRE-FE + participant PE-FE + participant TRC-FE + participant PD-FE + participant SCF + + TRE-FE->>TRE-FE: 1. Trigger + TRE-FE->>TRC-FE: 2. Resource notification + TRC-FE->>PD-FE: 3. Resource notification + PD-FE->>SCF: 4. Resource notification + TRC-FE->>PE-FE: 5. Resource release request/response +``` + +Y.2112(07)\_F.07 + +Sequence diagram for TRE-FE-indicated resource release procedure + +Figure 7 – TRE-FE-indicated resource release procedure + +#### 10.5.2 PE-FE-indicated resource release procedure + +The PE-FE-indicated resource release procedure shown in Figure 8 is the same as that defined in [ITU-T Y.2111]. + +![Sequence diagram for PE-FE-indicated resource release procedure](a734898ce18e972938949637c32a34f4_img.jpg) + +``` +sequenceDiagram + participant PE-FE + participant PD-FE + participant TRC-FE + participant SCF + + PE-FE->>PE-FE: 1. Trigger + PE-FE->>PD-FE: 2. Resource notification + PD-FE->>TRC-FE: 3. Resource release request/response + PD-FE->>SCF: 4. Resource notification +``` + +Y.2112(07)\_F.08 + +Sequence diagram for PE-FE-indicated resource release procedure + +Figure 8 – PE-FE-indicated resource release procedure + +#### 10.5.3 TRC-FE-indicated resource release procedure + +The TRC-FE-indicated resource release procedure shown in Figure 9 is the same as that defined in [ITU-T Y.2111]. + +![Sequence diagram showing the TRC-FE-indicated resource release procedure between PE-FE, PD-FE, TRC-FE, and SCF.](5445597cceefaca1ac89e710fe339325_img.jpg) + +``` +sequenceDiagram + participant PE-FE + participant PD-FE + participant TRC-FE + participant SCF + + TRC-FE->>TRC-FE: 1. Trigger + TRC-FE->>PD-FE: 2. Resource notification + TRC-FE->>SCF: 3. Resource notification + PD-FE->>PE-FE: 4. Resource release request + PE-FE->>PD-FE: 5. Resource release response +``` + +Y.2112(07)\_F.09 + +Sequence diagram showing the TRC-FE-indicated resource release procedure between PE-FE, PD-FE, TRC-FE, and SCF. + +**Figure 9 – TRC-FE-indicated resource release procedure** + +## 11 Deployment scenarios + +Depending on the specific environments, there are various RACF deployment scenarios. + +Assume that the access network has a star topology consisting of pipes between the EN and each AN. As such, all IP flows are forwarded through one edge node. + +Scenario 1: If it is assumed that the bandwidth per pipe is reserved and guaranteed, the topology of the access network is not of concern and admission control can be simplified. For example, RACF can perform admission control based on the reserved bandwidth for the user (i.e., the pipe), the total bandwidth of the existing connections over the pipe, and the bandwidth of the newly requested connection. + +Scenario 2: If it is assumed that the bottleneck of the bandwidth is limited, such as the link between the edge router and the first L2 switch, the resources of other links in the access network are not of concern and again admission control can be simplified. For example, RACF can perform admission control based on the provisioned bandwidth for such bottleneck link, the total bandwidth of the existing connection over the link, and the bandwidth of the newly requested connection. + +## 12 Security considerations + +This clause addresses security considerations specific to the Ethernet. Refer to [ITU-T Y.2111] for the general security considerations and requirements for the RACF. + +- To protect the communication between RACF entities in an Ethernet-based IP access network, a dedicated signalling network through the use of a separate VLAN or physical link can be used. +- MAC address filtering can be used to protect RACF functional entities from being accessed by illegitimate entities. +- To prevent the network topology and port state information from being modified by the CPE, the CPE is required to not be part of the spanning tree computation. As such, the spanning tree protocol (STP) is required to be enabled only on network-facing ports at a minimum. + +## Appendix I + +## Ethernet-based IP access networks and QoS + +(This appendix does not form an integral part of this Recommendation) + +In general, the bearer QoS (i.e., bearer network performance) control issues are network resource control issues. By implementing resource controls, the network performance can be optimized, including the upper bound on packet performance, i.e., delay, delay variation, and loss can be met. + +Depending on the resource attributes, an Ethernet-based IP access network could be partitioned into three segments, namely the last mile user access segment, the Ethernet level aggregation segment, and the IP level aggregation segment, if present. For each segment, there are typical QoS mechanisms available in the data plane. + +At the joint nodes such as access node, BRAS and edge router, the mapping between the different QoS mechanisms shall be done for end-to-end QoS delivery. + +These joint nodes enforce policy control and gate control. The related QoS mechanisms for different network segments are discussed below. + +### **QoS mechanisms in the last mile user access segment** + +The QoS mechanisms for the last mile segment are highly MAC technology-dependent and are out of the scope of this Recommendation. + +### **QoS mechanisms in the Ethernet level aggregation segment** + +[b-IEEE 802.1Q] defines eight priority levels and the traffic class expediting mechanisms utilizing these priorities for support of different classes of service. [b-IEEE 802.1Q] defines the tag format for adding VLAN ID, priority level and canonical format indicator fields into an Ethernet MAC frame header. They enable QoS information to be tagged onto any MAC frame, and thus enable Ethernet switches to handle the tagged frames with differentiation at the Ethernet layer. Queuing, scheduling, policing, shaping and filtering mechanisms can be applied based on classification and marking the 802.1Q tag. + +The inner VLAN could be configured per user from the access node to BRAS for user traffic separation, traceability and security, usually called the 'customer VLAN'. Q-in-Q (i.e., VLAN stacking defined by [b-IEEE 802.1ad]) mechanism could be used for Ethernet level traffic aggregation in case 4096 VLAN IDs are not enough. The granularity of the user VLAN could be smaller so that BRAS could easily distinguish service types and aggregate service traffic according to the VLAN ID without IP level inspection, e.g., a user may have multiple VLANs, each respectively for voice, video and data services. + +The access node is the first point where the traffic from multiple user access lines are aggregated into a single network, and thus should shape and police the traffic on a user access line to the subscribed access rate. BRAS should shape and police the traffic on user VLANs to the subscribed access rate and do the mapping between IP DSCPs and VLAN priorities. + +### **QoS mechanisms in the IP level aggregation segment** + +[b-IETF RFC 2474] defines the DSCPs (maximum 64) in the DiffServ field of the IP headers for support of different classes of service. [b-IETF RFC 2475] defines the DiffServ architecture utilizing these IP DSCPs. Queuing, scheduling, policing, shaping and filtering mechanisms can be applied based on classification and marking the IP DSCPs. At each DiffServ router, the packets that belong to the same class of service are subjected to the same per hop behaviour (PHB) (i.e., a group of forwarding behaviours). A number of PHBs and their related DSCPs have been standardized within IETF, including the expedited forwarding (EF) PHB, the assured forwarding (AF1~4) PHB group, and the default best effort (BE) PHB. + +The tunnels (e.g., L2TP, GRE), VLANs, MPLS LSPs and VPNs could be configured per service type or QoS class for IP level traffic aggregation as additions to native IP and for traffic separation among different services. MPLS LSPs can be established for resource reservation and explicit routing. BRAS and edge router should do the mapping between VLAN priorities, IP DSCPs, and MPLS EXP bits. + +## Appendix II + +## Last-mile user access technology + +(This appendix does not form an integral part of this Recommendation) + +The last mile user access technologies are diverse, e.g., LAN, xDSL, WLAN, EPON, PLC, etc. Different types of last mile user access systems have different types of modems and access nodes. Examples are given in Table II.1. This list is not exhaustive. + +**Table II.1 – Example mapping between last mile user access technologies and AN and modem types** + +| Last mile user access technology | Access node | Modem/Adapter | +|----------------------------------|-------------|---------------| +| LAN | L2 Switch | LAN adapter | +| xDSL | DSLAM | xDSL modem | +| WLAN | WLAN AP | WLAN adapter | +| Cable | CMTS | Cable Modem | +| PLC | EPLC-SHE | EPLC-SCPE | +| EPON | OLT | ONU | +| UMTS | RNC+Node B | USIM card | + +## Appendix III + +## Use cases + +(This appendix does not form an integral part of this Recommendation) + +### III.1 Overview + +This clause provides example use cases, which show how this Recommendation is applied and how it supports dynamic QoS control for Ethernet-based IP access networks. The functional entities defined are mapped into physical devices together with a high-level description of call procedure. + +### III.2 Voice over IP + +A VoIP use case (session establishment procedure from the caller's point of view) is shown in Figure III.1 and described below. + +![Figure III.1: Use case of VoIP (session establishment procedure from caller's point of view). The diagram illustrates the network architecture and the sequence of events for a VoIP session establishment. Key components include: Call server (containing Portal, Call server, and VoD middleware), NACF, RACF, SIP phone, CPN, STB, PC, RG, DSLAM, Ethernet, BRAS/ER, Voice, Video, and Internet. The sequence of events is numbered 1 through 8: (1) SIP phone initiates call; (2) Call server sends QoS request to RACF; (3) RACF requests subscription info from NACF; (4) RACF makes final decision and pushes gate control to DSLAM and BRAS; (5) DSLAM and BRAS acknowledge QoS installation; (6) RACF sends positive response to call server; (7) Call server initiates SIP INVITE to callee's call server; (8) Call server receives '200 OK' response and session is established. Reference points Ru and Rw are also indicated.](5132b3a97ac70fe4765c1e07e66b72b3_img.jpg) + +Y.2112(07)\_F.III.1 + +Figure III.1: Use case of VoIP (session establishment procedure from caller's point of view). The diagram illustrates the network architecture and the sequence of events for a VoIP session establishment. Key components include: Call server (containing Portal, Call server, and VoD middleware), NACF, RACF, SIP phone, CPN, STB, PC, RG, DSLAM, Ethernet, BRAS/ER, Voice, Video, and Internet. The sequence of events is numbered 1 through 8: (1) SIP phone initiates call; (2) Call server sends QoS request to RACF; (3) RACF requests subscription info from NACF; (4) RACF makes final decision and pushes gate control to DSLAM and BRAS; (5) DSLAM and BRAS acknowledge QoS installation; (6) RACF sends positive response to call server; (7) Call server initiates SIP INVITE to callee's call server; (8) Call server receives '200 OK' response and session is established. Reference points Ru and Rw are also indicated. + +**Figure III.1 – Use case of VoIP (session establishment procedure from caller's point of view)** + +- (1) The SIP Endpoint (i.e., CPE) initiates the SIP call. The SIP Endpoint sends a SIP INVITE to the destination SIP Endpoint. +- (2) The call server (i.e., SCF) sends the QoS request to RACF. +- (3) The RACF requests the subscription information of the requested service from NACF via Ru reference point. (See Note) +- (4) The RACF makes the final decision based on policy rules, resource availability and subscription information. If the QoS request is admitted, the RACF pushes the gate control, packet marking and bandwidth allocation decisions to the DSLAM and BRAS via Rw reference point. +- (5) The DSLAM and BRAS acknowledge the QoS installation. +- (6) The RACF sends positive response to the call server. +- (7) The call server initiates the SIP INVITE to the callee's call server. The callee's call server will initiate the similar procedure as the caller's call server. +- (8) The call server receives the "200 OK" response and the session is established. + +NOTE – This step is only needed if the RACF does not already have the subscription information from the NACF upon the attachment of the endpoint device to the access network. + +### III.3 Video on demand + +A video on demand use case (session establishment procedure) is shown in Figure III.2 and described below. + +![Figure III.2 – Use case of video on demand (session establishment procedure). The diagram shows a network architecture involving a Portal, Call server, and VoD middleware at the top. Below them are the NACF and RACF connected via the Ru reference point. The user side includes a SIP phone, STB, and PC connected through a CPN (Customer Premises Network) with an RG (Residential Gateway). This connects to a DSLAM, then through an Ethernet network to a BRAS/ER. The BRAS/ER connects to Voice, Video, and Internet services. Numbered red dashed lines (1-8) indicate the flow of the session establishment procedure.](26d664119ad25250780f554633444e54_img.jpg) + +``` + +graph TD + subgraph Service_Layer + Portal + CallServer[Call server] + VoD_Middleware[VoD middleware] + end + subgraph Control_Layer + NACF + RACF + end + subgraph Access_Network + CPN[CPN: SIP phone, STB, PC, RG] + DSLAM + Ethernet + BRAS_ER[BRAS/ER] + end + subgraph Services + Voice + Video + Internet + end + + CPN -- "(1) Request list/video" --> VoD_Middleware + VoD_Middleware -- "(2) QoS Request" --> RACF + RACF -- "(3) Subscription Info (Ru)" --> NACF + RACF -- "(4) Gate control/Bandwidth (Rw)" --> DSLAM + RACF -- "(4) Gate control/Bandwidth (Rw)" --> BRAS_ER + DSLAM -- "(5) Acknowledge" --> RACF + BRAS_ER -- "(5) Acknowledge" --> RACF + RACF -- "(6) Acknowledgement" --> VoD_Middleware + VoD_Middleware -- "(7) Inform delivery" --> Video + Video -- "(8) Video service with QoS" --> CPN + + CPN -- "Assign C-VLAN" --> DSLAM + DSLAM -- "Assign S-VLAN" --> BRAS_ER + +``` + +Figure III.2 – Use case of video on demand (session establishment procedure). The diagram shows a network architecture involving a Portal, Call server, and VoD middleware at the top. Below them are the NACF and RACF connected via the Ru reference point. The user side includes a SIP phone, STB, and PC connected through a CPN (Customer Premises Network) with an RG (Residential Gateway). This connects to a DSLAM, then through an Ethernet network to a BRAS/ER. The BRAS/ER connects to Voice, Video, and Internet services. Numbered red dashed lines (1-8) indicate the flow of the session establishment procedure. + +**Figure III.2 – Use case of video on demand (session establishment procedure)** + +- (1) The STB requests the list of program from EPG when it starts up. The STB sends the video request to the VoD middleware (SCF) with user name and password. +- (2) The VoD middleware authorizes the user and locates the video content. The VoD middleware sends the QoS request to RACF. +- (3) The RACF requests the subscription information of the requested service from NACF via Ru reference point. (See Note in clause III.4.) +- (4) The RACF makes the final decision based on policy rules, resource availability and subscription information. If the QoS request is admitted, the RACF pushes the gate control, packet marking and bandwidth allocation decisions to the DSLAM and BRAS via Rw reference point. +- (5) The DSLAM and BRAS acknowledge the QoS installation. +- (6) The RACF sends acknowledgement to the VoD middleware. +- (7) The VoD middleware informs the video server (e.g., CDN node) to deliver the requested video program. +- (8) The user receives the request video service with QoS guarantees. + +### III.4 Bandwidth on demand + +A bandwidth on demand use case (session establishment procedure) is shown in Figure III.3 and described below. + +![Figure III.3 – Use case of bandwidth on demand (session establishment procedure). The diagram illustrates a network architecture for bandwidth on demand. At the top, a 'Portal' (web portal) is connected to a 'Call server' and 'VoD middleware'. A 'NACF' (Network Access Control Function) is also connected to the 'Call server'. A 'RACF' (Resource Allocation Control Function) is connected to the 'Call server' and the 'NACF'. The 'RACF' is connected to a 'DSLAM' (Digital Subscriber Line Access Multiplexer) and a 'BRAS/ER' (Broadband Remote Access Server/Edge Router). The 'DSLAM' is connected to an 'Ethernet' network. The 'BRAS/ER' is connected to an 'Internet' service. The 'Ethernet' network is connected to a 'SIP phone', 'STB' (Set-Top Box), and 'PC' (Personal Computer) via a 'CPN' (Cable Port Network) and 'RG' (Residential Gateway). The 'SIP phone', 'STB', and 'PC' are connected to the 'RG'. The 'RG' is connected to the 'DSLAM'. The 'DSLAM' is connected to the 'Ethernet'. The 'Ethernet' is connected to the 'BRAS/ER'. The 'BRAS/ER' is connected to the 'Internet'. The 'Internet' is connected to 'Voice' and 'Video' services. The diagram shows the flow of a bandwidth on demand request from the user (SIP phone, STB, PC) through the network (RG, DSLAM, Ethernet, BRAS/ER) to the Internet service (Voice, Video). The flow is numbered 1 through 7, corresponding to the steps in the session establishment procedure.](cbdfdade780e677eb1c1aef3081ce9ef_img.jpg) + +Y.2112(07)\_F.III.3 + +Figure III.3 – Use case of bandwidth on demand (session establishment procedure). The diagram illustrates a network architecture for bandwidth on demand. At the top, a 'Portal' (web portal) is connected to a 'Call server' and 'VoD middleware'. A 'NACF' (Network Access Control Function) is also connected to the 'Call server'. A 'RACF' (Resource Allocation Control Function) is connected to the 'Call server' and the 'NACF'. The 'RACF' is connected to a 'DSLAM' (Digital Subscriber Line Access Multiplexer) and a 'BRAS/ER' (Broadband Remote Access Server/Edge Router). The 'DSLAM' is connected to an 'Ethernet' network. The 'BRAS/ER' is connected to an 'Internet' service. The 'Ethernet' network is connected to a 'SIP phone', 'STB' (Set-Top Box), and 'PC' (Personal Computer) via a 'CPN' (Cable Port Network) and 'RG' (Residential Gateway). The 'SIP phone', 'STB', and 'PC' are connected to the 'RG'. The 'RG' is connected to the 'DSLAM'. The 'DSLAM' is connected to the 'Ethernet'. The 'Ethernet' is connected to the 'BRAS/ER'. The 'BRAS/ER' is connected to the 'Internet'. The 'Internet' is connected to 'Voice' and 'Video' services. The diagram shows the flow of a bandwidth on demand request from the user (SIP phone, STB, PC) through the network (RG, DSLAM, Ethernet, BRAS/ER) to the Internet service (Voice, Video). The flow is numbered 1 through 7, corresponding to the steps in the session establishment procedure. + +**Figure III.3 – Use case of bandwidth on demand (session establishment procedure)** + +- (1) The user sends the BoD service request to the web portal. +- (2) The web portal interacts with the AAA system to validate the user and then sends a QoS request (i.e., bandwidth request) to RACF. +- (3) The RACF requests the subscription information of the requested service from NACF via the Ru reference point. (See Note.) +- (4) The RACF makes the final decision based on policy rules, resource availability and subscription information. If the QoS request is admitted, the RACF pushes the gate control, packet marking and bandwidth allocation decisions to the DSLAM and BRAS via Rw reference point. +- (5) The DSLAM and BRAS acknowledge the QoS installation. +- (6) The RACF sends acknowledgement to the web portal. +- (7) The user accesses the Internet service with the requested bandwidth. + +## Bibliography + +- [b-ITU-T Y.1221] ITU-T Recommendation Y.1221 (2002), *Traffic control and congestion control in IP-based networks*. +- [b-ITU-T Y.1241] ITU-T Recommendation Y.1241 (2001), *Support of IP-based services using IP transfer capabilities*. +- [b-ITU-T Y.1291] ITU-T Recommendation Y.1291 (2004), *An architectural framework for support of Quality of Service (QoS) in packet networks*. +- [b-ITU-T Y.1541] ITU-T Recommendation Y.1541 (2006), *Network performance objectives for IP-based services*. +- [b-IEEE 802.1Q] IEEE 802.1Q (2005), *Virtual Bridged Local Area Networks*. +- [b-IEEE 802.1ad] IEEE 802.1ad (2005), *Virtual Bridged Local Area Networks – Amendment 4: Provider Bridges*. +- [b-IEEE 802.1AB] IEEE 802.1AB (2005), *Station and Media Access Control Connectivity Discovery*. +- [b-IEEE 802.1D] IEEE 802.1D (2004), *Media Access Control (MAC) Bridges*. +- [b-IETF RFC 2284] IETF RFC 2284 (1998), *PPP Extensible Authentication Protocol (EAP)*. +- [b-IETF RFC 2474] IETF RFC 2474 (1998), *Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Headers*. +- [b-IETF RFC 2475] IETF RFC 2475 (1998), *An Architecture for Differentiated Services*. +- [b-IETF RFC 2753] IETF RFC 2753 (2000), *A Framework for Policy-based Admission Control*. +- [b-IETF RFC 3270] IETF RFC 3270 (2002), *Multi-Protocol Label Switching (MPLS) Support of Differentiated Services*. +- [b-DSL TR-101] DSL Forum TR-101 (2006), *Migration to Ethernet Based DSL Aggregation*. + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|--------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/Y/T-REC-Y.2171-200609-I_PDF-E/a3dc41dc3df86ea68d266af2bf95cf5b_img.jpg b/marked/Y/T-REC-Y.2171-200609-I_PDF-E/a3dc41dc3df86ea68d266af2bf95cf5b_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..36cf51f8ba07e44aa7a4b009f3ba08eb2b570b1c --- /dev/null +++ b/marked/Y/T-REC-Y.2171-200609-I_PDF-E/a3dc41dc3df86ea68d266af2bf95cf5b_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:11780faeee75ba39ab4ed9de67a9e67abec0d9ba3068ebec661dea70c16e29d3 +size 4338 diff --git a/marked/Y/T-REC-Y.2215-200906-I_PDF-E/raw.md b/marked/Y/T-REC-Y.2215-200906-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..884f3a1ec3025c8091ccda614344454f03f12a9c --- /dev/null +++ b/marked/Y/T-REC-Y.2215-200906-I_PDF-E/raw.md @@ -0,0 +1,601 @@ + + +I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +## Y.2215 + +(06/2009) + +SERIES Y: GLOBAL INFORMATION +INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS +AND NEXT-GENERATION NETWORKS + +Next Generation Networks – Service aspects: Service +capabilities and service architecture + +# --- **Requirements and framework for the support of VPN services in NGN, including the mobile environment** + +Recommendation ITU-T Y.2215 + +![ITU logo](84a1d09fb489061482111515543b60dc_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with a red lightning bolt striking it, and the text "ITU" in blue, with "International Telecommunication Union" in smaller blue text below it. + +ITU logo + +## ITU-T Y-SERIES RECOMMENDATIONS **GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT- GENERATION NETWORKS** + +## GLOBAL INFORMATION INFRASTRUCTURE + +| | | +|-------------------------------------------|-------------| +| General | Y.100–Y.199 | +| Services, applications and middleware | Y.200–Y.299 | +| Network aspects | Y.300–Y.399 | +| Interfaces and protocols | Y.400–Y.499 | +| Numbering, addressing and naming | Y.500–Y.599 | +| Operation, administration and maintenance | Y.600–Y.699 | +| Security | Y.700–Y.799 | +| Performances | Y.800–Y.899 | + +## INTERNET PROTOCOL ASPECTS + +| | | +|--------------------------------------------------------------------|---------------| +| General | Y.1000–Y.1099 | +| Services and applications | Y.1100–Y.1199 | +| Architecture, access, network capabilities and resource management | Y.1200–Y.1299 | +| Transport | Y.1300–Y.1399 | +| Interworking | Y.1400–Y.1499 | +| Quality of service and network performance | Y.1500–Y.1599 | +| Signalling | Y.1600–Y.1699 | +| Operation, administration and maintenance | Y.1700–Y.1799 | +| Charging | Y.1800–Y.1899 | +| IPTV over NGN | Y.1900–Y.1999 | + +## NEXT GENERATION NETWORKS + +| | | +|-----------------------------------------------------------------------|----------------------| +| Frameworks and functional architecture models | Y.2000–Y.2099 | +| Quality of Service and performance | Y.2100–Y.2199 | +| Service aspects: Service capabilities and service architecture | Y.2200–Y.2249 | +| Service aspects: Interoperability of services and networks in NGN | Y.2250–Y.2299 | +| Numbering, naming and addressing | Y.2300–Y.2399 | +| Network management | Y.2400–Y.2499 | +| Network control architectures and protocols | Y.2500–Y.2599 | +| Future networks | Y.2600–Y.2699 | +| Security | Y.2700–Y.2799 | +| Generalized mobility | Y.2800–Y.2899 | +| Carrier grade open environment | Y.2900–Y.2999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +## **Recommendation ITU-T Y.2215** + +# **Requirements and framework for the support of VPN services in NGN, including the mobile environment** + +## **Summary** + +Recommendation ITU-T Y.2215 specifies service requirements and framework for the support of VPN services in NGN, including the mobile environment. + +## **Source** + +Recommendation ITU-T Y.2215 was approved on 29 June 2009 by ITU-T Study Group 13 (2009-2012) under Recommendation ITU-T A.8 procedures. + +## **Keywords** + +Functions, mobile, next generation network, service requirements, virtual private network. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2009 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## CONTENTS + +| | Page | +|--------------------------------------------------------------------------------------|-------------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 2 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 3 | +| 6 Introduction ..... | 3 | +| 7 Service requirements ..... | 4 | +| 7.1 General requirements..... | 4 | +| 7.2 Configuration management ..... | 4 | +| 7.3 Service level agreements and quality of service..... | 5 | +| 7.4 Security..... | 5 | +| 7.5 Fault management ..... | 5 | +| 7.6 Performance management ..... | 6 | +| 7.7 Accounting ..... | 6 | +| 7.8 Mobility ..... | 6 | +| 7.9 Multicast..... | 6 | +| 8 VPN framework architecture..... | 6 | +| 8.1 VPN functions at the service stratum ..... | 7 | +| 8.2 VPN functions at the transport stratum ..... | 8 | +| 8.3 VPN end-user functions ..... | 9 | +| 8.4 VPN management functions..... | 9 | +| 9 Security..... | 9 | +| Appendix I – Scenarios of VPN services in NGN, including the mobile environment..... | 10 | +| I.1 Virtual corporate office ..... | 10 | +| I.2 Personal end-to-end VPN ..... | 11 | +| I.3 Community-based VPN..... | 12 | +| Bibliography ..... | 14 | + + + +# Recommendation ITU-T Y.2215 + +# Requirements and framework for the support of VPN services in NGN, including the mobile environment + +## 1 Scope + +This Recommendation identifies service requirements and functional framework for the support of VPN services in NGN, including the mobile environment. + +The provision of VPN services in NGN, including the mobile environment, covers the support of mobility management functions across different fixed and wireless network domains as well as at different network levels including intra-access network, inter-access network, and inter-network levels [ITU-T Q.1706]. This includes mobility support at the NGN service stratum and the NGN transport stratum [b-ITU-T Y.2011]. + +The detailed definition of mobility management-related functions and architecture is outside the scope of this Recommendation. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +| | | +|----------------|-------------------------------------------------------------------------------------------------------------------| +| [ITU-T Q.1706] | Recommendation ITU-T Q.1706/Y.2801 (2006), Mobility management requirements for NGN . | +| [ITU-T Y.1311] | Recommendation ITU-T Y.1311 (2002), Networked-based VPNs – Generic architecture and service requirements . | +| [ITU-T Y.2012] | Recommendation ITU-T Y.2012 (2006), Functional requirements and architecture of the NGN release 1 . | +| [ITU-T Y.2201] | Recommendation ITU-T Y.2201 (2007), NGN release 1 requirements . | +| [ITU-T Y.2236] | Recommendation ITU-T Y.2236 (2009), Framework for NGN support of multicast-based services . | +| [ITU-T Y.2701] | Recommendation ITU-T Y.2701 (2007), Security requirements for NGN release 1 . | + +## 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 access control** [b-ITU-T X.800]: The prevention of unauthorized use of a resource, including the prevention of use of a resource in an unauthorized manner. + +**3.1.2 access network** [b-ITU-T Q.1742.1]: Network that connects access technologies (such as a Radio Access Network) to the core network. + +**3.1.3 accounting** [b-ITU-T Y.2233]: The process of collecting and analysing NGN service and NGN resource usage metrics for the purposes of capacity and trend analysis, cost allocation, auditing, and billing, etc. Accounting management requires that resource consumption be measured, rated, assigned, and communicated between appropriate business entities. + +**3.1.4 billing** [b-ITU-T Y.2233]: The process after rating in which the NGN transactions of NGN event usage are compiled and bills are produced. + +**3.1.5 charging** [b-ITU-T Y.2233]: Function within the NGN network and the associated OCS/BD components whereby information related to a chargeable event is collected, formatted, transferred and evaluated in order to make it possible to determine usage for which the charged party may be billed (offline charging) or the subscriber's account balance may be debited (online charging). + +**3.1.6 mobility** [ITU-T Q.1706]: The ability for the user or other mobile entities to communicate and access services irrespective of changes of the location or technical environment. + +**3.1.7 mobility management** [ITU-T Q.1706]: The set of functions used to provide mobility. These functions include authentication, authorization, location updating, paging, download of user information and more. + +**3.1.8 personal mobility** [ITU-T Q.1706] and [ITU-T Y.2201]: This is the mobility for those scenarios where the user changes the terminal used for network access at different locations. The ability of a user to access telecommunication services at any terminal on the basis of a personal identifier, and the capability of the network to provide those services delineated in the user's service profile. + +**3.1.9 quality of service (QoS)** [b-ITU-T G.1000]: The collective effect of service performances, which determine the degree of satisfaction of a user of the service. + +**3.1.10 service continuity** [ITU-T Y.2201]: The ability for a moving object to maintain ongoing service over including current states, such as user's network environment and session for a service. + +**3.1.11 service level agreement** [b-ITU-T G.8081]: A contract between two parties such as a service provider and a customer. It defines the services available to the customer, and the grade of service of those services as offered to the customer. It also usually describes the service guarantee and potential penalties in case of service degradation or failure. + +**3.1.12 terminal mobility** [ITU-T Q.1706] and [ITU-T Y.2201]: This is the mobility for those scenarios where the same terminal equipment is moving or is used at different locations. The ability of a terminal to access telecommunication services from different locations and while in motion, and the capability of the network to identify and locate that terminal. + +### **3.2 Terms defined in this Recommendation** + +This Recommendation defines the following term: + +**3.2.1 virtual private network (VPN)**: A VPN is a communication network, built over public and/or private network resources, used to support controlled and secure communications within a group of users as if they were on a private network. + +## **4 Abbreviations and acronyms** + +This Recommendation uses the following abbreviations: + +| | | +|-----|----------------------------------| +| ANI | Application-to-Network Interface | +| CE | Customer Equipment | +| CPE | Customer Premises Equipment | + +| | | +|--------|----------------------------------------------| +| GRE | Generic Routing Encapsulation | +| GTP | GPRS Tunnelling Protocol | +| IGMP | Internet Group Management Protocol | +| IKE | Internet Key Exchange | +| IMS | IP Multimedia Subsystem | +| IP | Internet Protocol | +| L2TP | L2 Tunnelling Protocol | +| LAN | Local Area Network | +| mGRE | multipoint Generic Routing Encapsulation | +| MPLS | MultiProtocol Label Switching | +| NACF | Network Attachment Control Functions | +| NGN | Next Generation Network | +| NNI | Network-to-Network Interface | +| PD-FE | Policy Decision Functional Entity | +| PE | Provider Equipment | +| PE-FE | Policy Enforcement Functional Entity | +| QoS | Quality of Service | +| RACF | Resource and Admission Control Functions | +| SA | Security Association | +| SCF | Service Control Functions | +| SLA | Service Level Agreement | +| TRC-FE | Transport Resource Control Functional Entity | +| UNI | User-to-Network Interface | +| VPN | Virtual Private Network | + +## **5 Conventions** + +None. + +## **6 Introduction** + +The support of virtual private network (VPN) services in NGN including mobile environment allows multipoint controlled and secured communication services using NGN resources for the exchange of multimedia streams within a group of service users. + +Types of VPN services in NGN include: + +- Site-to-site VPNs that link branch offices, suppliers, partners, customers, and communities of interest; +- Access VPNs that accommodate mobile workers and telecommuters allowing them to securely access their corporate network from outside the office; +- Multiservice VPNs that support multimedia communications with end-to-end QoS provision. + +Appendix I provides scenarios for enhanced applications and services supported via the use of VPN services. + +This Recommendation builds upon the NGN capabilities specified in [ITU-T Y.2201]. + +## **7 Service requirements** + +This clause addresses the requirements for VPN services when provided in NGN, including the mobile environment. + +### **7.1 General requirements** + +For the support of VPN services [ITU-T Y.1311], NGN is required to provide: + +- support for fixed and mobile users; +- means for users to specify VPN membership; +- accommodation of user-defined VPN addressing schemes; +- transparency to user data; +- means for single customer site to belong concurrently to more than one VPN; +- provision of arbitrary user-defined VPN topologies (ranging, for example, from hub-and-spoke, partial mesh to full mesh); +- provision for multiprotocol support; +- provision of multi-homed user sites; +- provision of standards-based interfaces (independent of user's device supplier); +- support for wide range of routing protocols between CE and PE routers [ITU-T Y.1311]; +- means to support a variety of user's traffic (QoS) requirements as defined by the user, or negotiated/renegotiated (e.g., between the user and the provider); +- means to support different modes of communication: one-to-one, one-to-many, many-to-one and many-to-many; +- means to offer, support and maintain agreed levels of service (e.g., via service level agreements); +- means to meet user's security requirements (e.g., in terms of different security levels); +- provision of VPN members with secure dynamic access to VPN (e.g., via dial-up); +- provision of appropriate VPN management services in the areas of configuration, SLAs and QoS, security, fault, performance, accounting, mobility and multicast; +- accommodation for growth of a given VPN or a number of VPNs; +- means of ensuring service and transport level compatibility among VPN members (e.g., tunnelling, codecs). + +### **7.2 Configuration management** + +NGN is required to provide: + +- configuration capabilities for VPN members at both the service and the transport level (e.g., dynamic creation and modification of VPNs, according to specific application requirements and/or user requirements); +- consistency and coherence verification of user configuration information; +- ability to easily change topology; +- ability to easily add, remove or modify VPN-related devices, sites, routes, etc.; + +- ability to accommodate growth requirements for VPN related devices, sites, routes, traffic, etc. + +### **7.3 Service level agreements and quality of service** + +NGN is required to support mechanisms for negotiating service level agreements (SLAs) with the (fixed or mobile) subscriber/user (e.g., per VPN, per VPN site, per VPN connection). + +SLAs include: + +- service level objectives, e.g.: + - bandwidth (e.g., tunnel bandwidth); + - QoS parameters (e.g., packet loss rate, latency); + - availability; + - reliability; + - security; + - priority; +- service monitoring objectives: + - QoS monitoring; + - flow tracking; + - reporting. + +NGN is required to provide mechanisms to ensure QoS support as required by SLAs. These mechanisms include VPN-related resource and admission control mechanisms such as: + +- priority management (e.g., per VPN, per VPN site, per VPN connection); +- traffic class differentiation; +- QoS signalling; +- performance measurement; +- overload/congestion control. + +### **7.4 Security** + +NGN is required to support mechanisms for: + +- controlling (fixed or mobile) user access to the VPN via access control mechanisms (identification, authentication and authorization of (fixed or mobile) users accessing the VPN); +- ensuring the privacy of data being transported by the VPN; +- secure key distribution; +- secure and efficient SLA negotiation; +- security policies to satisfy users and/or providers' security requirements (e.g., to adjust the configuration of VPN users or VPN groups, to reflect trust relationships). + +### **7.5 Fault management** + +NGN is recommended to provide: + +- information to the VPN customer in the event of service disruption and restoration; +- dynamic VPN recovery, non-disruptive and not perceived by the VPN users; +- provision of relevant VPN incident reports and summaries. + +### **7.6 Performance management** + +NGN is recommended to support: + +- maintenance of VPN performance consistent with SLAs; +- provision of VPN performance information, including statistics; +- ability to demonstrate performance to VPN customer; +- prediction of VPN trends, likely problems and/or recommendations in relation to current SLAs, traffic patterns, QoS, etc. + +### **7.7 Accounting** + +NGN is required to support: + +- provision of accounting information to VPN customer/users; +- customized breakdown of VPN accounting information; +- correlation of accounting to QoS and/or SLAs; +- correlation of accounting to VPN performance and fault management information. + +### **7.8 Mobility** + +NGN is required to support: + +- nomadism for personal (i.e., VPN user) and terminal (i.e., VPN user terminal) mobility. + +NGN is recommended to support: + +- service continuity [ITU-T Q.1706] for terminal mobility. + +In particular, NGN is required to support: + +- service continuity for terminal mobility in case of VPN voice services. + +### **7.9 Multicast** + +NGN is recommended to support: + +- multicast capabilities within a VPN, e.g., to support specific applications such as linear TV within a VPN. + +If multicast capabilities are supported, NGN is required to support: + +- creation, operation and release of multicast groups within a VPN; +- mechanisms to manage multicast connections within a VPN (i.e., all multicast trees within that VPN); +- mechanisms allowing VPN members to join and leave multicast groups within a VPN. + +## **8 VPN framework architecture** + +This clause identifies the new functions and extensions/modifications of the various functions of the NGN functional architecture [ITU-T Y.2012] in order to support VPN services in NGN, including the mobile environment. + +Figure 1 shows the VPN framework architecture based on the NGN functional architecture [ITU-T Y.2012] for the provision of VPN services in NGN, including the mobile environment. + +![Figure 1 – VPN framework architecture based on [ITU-T Y.2012]. The diagram shows a layered architecture. At the top is 'Applications' connected to the 'Service Stratum' via the 'ANI' (Application Network Interface). The 'Service Stratum' (green box) contains 'VPN Application Support Functions & Service Support Functions' and 'VPN Service Control Functions' (which includes 'VPN Service User Profiles', 'VPN Membership Management Functions', and 'VPN Multicast Service Control Functions'). Below the Service Stratum is the 'Transport Stratum' (yellow box), which contains 'VPN Network Attachment and Control Functions' (including 'VPN Transport User Profiles'), 'VPN Resource Admission Control Functions', 'VPN Connection Management Functions', and 'VPN Transport Control Functions'. At the bottom is 'VPN Transport Functions'. To the left is a vertical purple bar for 'VPN Management Functions'. To the right is a white box for 'Other Networks'. Connections are shown: dashed green lines for management (UNI, NNI), solid red lines for media (UNI, NNI), and dotted black lines for control. A legend at the bottom indicates: dotted black line for Control, solid red line for Media, and dashed green line for Management.](af7916c89a458fdab6c3f443217388ae_img.jpg) + +Figure 1 – VPN framework architecture based on [ITU-T Y.2012]. The diagram shows a layered architecture. At the top is 'Applications' connected to the 'Service Stratum' via the 'ANI' (Application Network Interface). The 'Service Stratum' (green box) contains 'VPN Application Support Functions & Service Support Functions' and 'VPN Service Control Functions' (which includes 'VPN Service User Profiles', 'VPN Membership Management Functions', and 'VPN Multicast Service Control Functions'). Below the Service Stratum is the 'Transport Stratum' (yellow box), which contains 'VPN Network Attachment and Control Functions' (including 'VPN Transport User Profiles'), 'VPN Resource Admission Control Functions', 'VPN Connection Management Functions', and 'VPN Transport Control Functions'. At the bottom is 'VPN Transport Functions'. To the left is a vertical purple bar for 'VPN Management Functions'. To the right is a white box for 'Other Networks'. Connections are shown: dashed green lines for management (UNI, NNI), solid red lines for media (UNI, NNI), and dotted black lines for control. A legend at the bottom indicates: dotted black line for Control, solid red line for Media, and dashed green line for Management. + +**Figure 1 – VPN framework architecture based on [ITU-T Y.2012]** + +### **8.1 VPN functions at the service stratum** + +The service stratum provides the VPN service level functions which include VPN application support and service support functions and VPN service control functions. + +#### **8.1.1 VPN application support and service support** + +The VPN application support and service support functions work in conjunction with the VPN service control functions to provide VPN end-users and VPN applications with the capabilities they request. + +VPN application interactions with the VPN application support and service support functions are handled through the ANI reference point. + +#### **8.1.2 VPN service control** + +The VPN service control functions (including VPN membership management and VPN multicast service control functions) provide service control functions for VPN applications including interaction with service user profiles. VPN service control functions provide the capabilities to: + +- register VPN members; +- authenticate and authorize VPN members; +- select data encryption methods, and key exchanges, if required; +- negotiate QoS and SLA; +- perform mobility management; +- perform session control among VPN members; +- perform VPN membership management, as described in clause 8.1.2.1; +- perform VPN multicast service control within a VPN, as described in clause 8.1.2.2. + +##### **8.1.2.1 VPN membership management** + +The VPN membership management functions provide support for: + +- creation, maintenance and release of VPNs; +- joining and leaving VPNs; +- partitioning of a VPN into multiple VPN groups (including VPN multicast groups). + +The VPN membership management functions interact with multicast group membership management functions [ITU-T Y.2236] for VPN multicast group membership management. + +##### **8.1.2.2 VPN multicast service control** + +The VPN multicast service control functions use multicast service control functions [ITU-T Y.2236] to control VPN multicast groups. + +### **8.2 VPN functions at the transport stratum** + +#### **8.2.1 VPN transport control** + +The VPN transport control functions provide VPN resource and admission control functions, VPN network attachment control functions and VPN connection management functions. + +##### **8.2.1.1 VPN resource and admission control** + +Resource and admission control functions for VPNs provide VPN resource management to support QoS (including resource reservation) and VPN admission control in the transport stratum. + +VPN resource management includes: intra-VPN resource calculation, VPN path selection, mapping of VPN network topology to transport resources, maintenance of VPN membership information, policy management. + +VPN admission control involves checking authorizations based on user profiles, SLAs, operator specific policy rules, service priority, and resource availability within access and core transport networks. + +##### **8.2.1.2 VPN network attachment control** + +The VPN network attachment control functions provide registration of VPN users at the access level and initialization of VPN end-user functions for accessing VPN services. + +The VPN network attachment control functions provide VPN network-level identification and VPN user authentication and authorization (based on VPN user profiles). + +The VPN network attachment control functions also manage the VPN related IP address space, authenticate VPN access connections, and announce to VPN users the contact point(s) of VPN related functions in the NGN service stratum. + +The VPN network attachment control functions also provide VPN configuration based on VPN user profiles (e.g., QoS related profile information). + +The VPN network attachment control functions provide support for VPN transport user profile, which takes the form of a functional database including VPN user's information and other VPN user related control data. + +##### **8.2.1.3 VPN connection management** + +The VPN connection management functions provide management of VPN connections (tunnel management). The VPN connection management functions include the VPN multicast connection management functions. + +###### **8.2.1.3.1 VPN multicast connection management** + +The VPN multicast connection management functions use multicast connection management functions [ITU-T Y.2236] to control VPN multicast connections (i.e., all multicast trees within a VPN). + +#### **8.2.2 VPN transport** + +The VPN transport functions provide transport level functions (e.g., VPN traffic forwarding). + +### **8.3 VPN end-user functions** + +The VPN end-user functions provide support for: + +- SLAs and QoS levels, enabling various VPN traffic engineering mechanisms such as service priority control, packet filtering, traffic classification, rate limiting, resource reservation and admission control at the transport stratum; +- VPN join/leave; +- VPN group join/leave (including VPN multicast groups); +- VPN security providing support for VPN end-user traffic encryption/decryption, VPN end-user authentication and other VPN end-user security features, such as access control and security assurance control. + +### **8.4 VPN management functions** + +These functions are out of scope of this Recommendation. + +## **9 Security** + +Security of VPN services in NGN, including the mobile environment, is required to satisfy both NGN security requirements as contained in [ITU-T Y.2701] and VPN specific security requirements as described in clause 7. + +## Appendix I + +## Scenarios of VPN services in NGN, including the mobile environment + +(This appendix does not form an integral part of this Recommendation) + +This appendix describes scenarios of VPN services in NGN, including the mobile environment. + +### I.1 Virtual corporate office + +Figure I.1 illustrates a VPN scenario called "virtual corporate office" where a "hub-and-spoke" topology model is used, i.e., a model in which the corporate resources are supported in a central head office site (corresponding to the "hub"), with a number of mobile workers or branch offices (corresponding to the "spokes") connected to the head office site using VPN tunnels provided by the NGN. + +![Diagram of the Virtual corporate office scenario using a hub-and-spoke topology model.](41a438d7e4adc17c3a4005e7c9500091_img.jpg) + +The diagram illustrates a "hub-and-spoke" topology for a virtual corporate office. At the center is the "NGN core". To the right, the "Head office" (the hub) is represented by a building icon and contains a "VPN gateway". To the left, there are two "spoke" locations: "Mobile workers" (each with a person icon and a device, either a mobile phone or a laptop) and a "Branch office" (represented by a building icon) which also contains a "VPN gateway". Each spoke location is connected to the NGN core via a "Mobile access network". Green lines represent "VPN tunnels" connecting the mobile access networks of the mobile workers and the branch office to the VPN gateway at the head office. Black arrows represent "Data paths" showing communication between the mobile workers, the branch office, and the head office through the NGN core. A legend at the bottom indicates that a green line represents a "VPN tunnel" and a black arrow represents a "Data path". The identifier "Y.2215(09)\_F1.1" is located in the bottom right corner of the diagram area. + +Diagram of the Virtual corporate office scenario using a hub-and-spoke topology model. + +**Figure I.1 – Virtual corporate office scenario – "hub-and-spoke" model** + +Figure I.2 shows another virtual corporate office scenario where a "spoke-to-spoke" topology model is used. This model provides the ability to use temporary VPN tunnels, e.g., between mobile worker terminals and branch office sites. + +![Diagram of the 'spoke-to-spoke model' for a virtual corporate office scenario. It shows a central NGN core connected to three access networks: two mobile access networks (each with a mobile worker) and two fixed access networks (each with a VPN gateway and an office building). The fixed access networks are labeled 'Branch office' and 'Head office'. A legend at the bottom indicates that a green line represents a 'VPN tunnel', a purple line represents a 'VPN temporary tunnel', and a double-headed arrow represents a 'Data path'. The diagram shows data paths from mobile workers through their respective access networks and the NGN core to the VPN gateways of the branch and head offices. A temporary tunnel is also shown between the two VPN gateways.](8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg) + +Diagram of the 'spoke-to-spoke model' for a virtual corporate office scenario. It shows a central NGN core connected to three access networks: two mobile access networks (each with a mobile worker) and two fixed access networks (each with a VPN gateway and an office building). The fixed access networks are labeled 'Branch office' and 'Head office'. A legend at the bottom indicates that a green line represents a 'VPN tunnel', a purple line represents a 'VPN temporary tunnel', and a double-headed arrow represents a 'Data path'. The diagram shows data paths from mobile workers through their respective access networks and the NGN core to the VPN gateways of the branch and head offices. A temporary tunnel is also shown between the two VPN gateways. + +**Figure I.2 – Virtual corporate office scenario – "spoke-to-spoke model"** + +The two models above can be used to provide multiservice VPNs. + +Multiservice VPNs allow to deliver multimedia applications with an end-to-end quality of service. They require that the VPN support appropriate QoS mechanisms (for voice, video and data), so that real-time voice and video traffic flows are properly classified and prioritized to support applications efficiently. + +Multiservice VPNs support different networking capabilities in order to support VPN user requirements in terms of services, QoS and security. + +Multiservice VPNs can support flexible virtual network topologies (e.g., built on a per application basis). + +### **I.2 Personal end-to-end VPN** + +Figure I.3 illustrates a "personal end-to-end VPN" scenario in which end-to-end VPN tunnels are used between VPN user terminals. This scenario does not require specific capabilities from the NGN apart from allowing the end-to-end tunnels to be carried through the NGN. + +![Figure I.3 – Personal end-to-end VPN scenario. This diagram illustrates a personal end-to-end VPN scenario. It features three mobile access networks, each represented by an oval containing a user icon and a device (mobile phone or laptop). These networks are connected to a central NGN core, represented by a large oval. Green lines represent VPN tunnels, showing connections from each mobile access network to the NGN core. Black arrows represent data paths, showing bidirectional communication between the mobile access networks and the NGN core. A legend at the bottom indicates that a green line represents a VPN tunnel and a black arrow represents a data path.](76b0cd79baaedd942af4dc42f2e764b8_img.jpg) + +Figure I.3 – Personal end-to-end VPN scenario. This diagram illustrates a personal end-to-end VPN scenario. It features three mobile access networks, each represented by an oval containing a user icon and a device (mobile phone or laptop). These networks are connected to a central NGN core, represented by a large oval. Green lines represent VPN tunnels, showing connections from each mobile access network to the NGN core. Black arrows represent data paths, showing bidirectional communication between the mobile access networks and the NGN core. A legend at the bottom indicates that a green line represents a VPN tunnel and a black arrow represents a data path. + +**Figure I.3 – Personal end-to-end VPN scenario** + +## I.3 Community-based VPN + +Figure I.4 shows a community-based VPN scenario. This scenario consists in using VPNs and groups within those VPNs to form communities (e.g., similar to web-based communities) which the users can join or leave. VPN users using community-based VPN services can make use of different types of terminals, for instance, personal computers, laptops, mobile devices, etc. + +Community-based VPNs allow to form different community groups. Community groups are groups of VPN users who are members of the same community, thus having access to the same set of services and applications provided within that community. + +![Figure I.4 – Community-based VPN scenario. This diagram illustrates a community-based VPN scenario. It shows a central NGN wired / mobile environment, represented by a green cloud. Surrounding this central environment are several access networks, each represented by a dashed oval containing a user icon and a device (laptop, mobile phone, or desktop computer). These access networks are grouped into two community groups: Community group A (enclosed in a yellow oval) and Community group B (enclosed in a blue oval). The diagram shows how users from different access networks can connect to the central NGN environment and form part of a community group. A legend at the bottom indicates that a yellow line represents a VPN tunnel and a blue line represents a data path.](9cd90f495b95ad2116ff780248c26d95_img.jpg) + +Figure I.4 – Community-based VPN scenario. This diagram illustrates a community-based VPN scenario. It shows a central NGN wired / mobile environment, represented by a green cloud. Surrounding this central environment are several access networks, each represented by a dashed oval containing a user icon and a device (laptop, mobile phone, or desktop computer). These access networks are grouped into two community groups: Community group A (enclosed in a yellow oval) and Community group B (enclosed in a blue oval). The diagram shows how users from different access networks can connect to the central NGN environment and form part of a community group. A legend at the bottom indicates that a yellow line represents a VPN tunnel and a blue line represents a data path. + +**Figure I.4 – Community-based VPN scenario** + +Community-based VPNs provide management of community groups related-user information as well as other community groups characteristics, for example in the area of security, QoS and applications provided to the community group users. + +## Bibliography + +- [b-ITU-T G.1000] Recommendation ITU-T G.1000 (2001), *Communications Quality of Service: A framework and definitions*. +- [b-ITU-T G.8081] Recommendation ITU-T G.8081/Y.1353 (2008), *Terms and definitions for Automatically Switched Optical Networks (ASON)*. +- [b-ITU-T Q.1742.1] Recommendation ITU-T Q.1742.1 (2002), *IMT-2000 references to ANSI-41 evolved core network with cdma2000 access network*. +- [b-ITU-T X.800] Recommendation ITU-T X.800 (1991), *Security architecture for Open Systems Interconnection for CCITT applications*. +- [b-ITU-T Y.2011] Recommendation ITU-T Y.2011 (2004), *General principles and general reference model for Next Generation Networks*. +- [b-ITU-T Y.2233] Recommendation ITU-T Y.2233 (2008), *Requirements and framework allowing accounting and charging capabilities in NGN*. + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|--------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Terminals and subjective and objective assessment methods | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/Y/T-REC-Y.2222-201304-I_PDF-E/raw.md b/marked/Y/T-REC-Y.2222-201304-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..0a9889de6829d2457e70baf2a2216390b46821ec --- /dev/null +++ b/marked/Y/T-REC-Y.2222-201304-I_PDF-E/raw.md @@ -0,0 +1,904 @@ + + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +## Y.2222 + +(04/2013) + +SERIES Y: GLOBAL INFORMATION +INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS +AND NEXT-GENERATION NETWORKS + +Next Generation Networks – Service aspects: Service +capabilities and service architecture + +# --- **Sensor control networks and related applications in a next generation network environment** + +Recommendation ITU-T Y.2222 + +# ITU-T Y-SERIES RECOMMENDATIONS **GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT- GENERATION NETWORKS** + +| | | +|-----------------------------------------------------------------------|----------------------| +| GLOBAL INFORMATION INFRASTRUCTURE | | +| General | Y.100–Y.199 | +| Services, applications and middleware | Y.200–Y.299 | +| Network aspects | Y.300–Y.399 | +| Interfaces and protocols | Y.400–Y.499 | +| Numbering, addressing and naming | Y.500–Y.599 | +| Operation, administration and maintenance | Y.600–Y.699 | +| Security | Y.700–Y.799 | +| Performances | Y.800–Y.899 | +| INTERNET PROTOCOL ASPECTS | | +| General | Y.1000–Y.1099 | +| Services and applications | Y.1100–Y.1199 | +| Architecture, access, network capabilities and resource management | Y.1200–Y.1299 | +| Transport | Y.1300–Y.1399 | +| Interworking | Y.1400–Y.1499 | +| Quality of service and network performance | Y.1500–Y.1599 | +| Signalling | Y.1600–Y.1699 | +| Operation, administration and maintenance | Y.1700–Y.1799 | +| Charging | Y.1800–Y.1899 | +| IPTV over NGN | Y.1900–Y.1999 | +| NEXT GENERATION NETWORKS | | +| Frameworks and functional architecture models | Y.2000–Y.2099 | +| Quality of Service and performance | Y.2100–Y.2199 | +| Service aspects: Service capabilities and service architecture | Y.2200–Y.2249 | +| Service aspects: Interoperability of services and networks in NGN | Y.2250–Y.2299 | +| Enhancements to NGN | Y.2300–Y.2399 | +| Network management | Y.2400–Y.2499 | +| Network control architectures and protocols | Y.2500–Y.2599 | +| Packet-based Networks | Y.2600–Y.2699 | +| Security | Y.2700–Y.2799 | +| Generalized mobility | Y.2800–Y.2899 | +| Carrier grade open environment | Y.2900–Y.2999 | +| FUTURE NETWORKS | Y.3000–Y.3499 | +| CLOUD COMPUTING | Y.3500–Y.3999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# **Recommendation ITU-T Y.2222** + +# **Sensor control networks and related applications in a next generation network environment** + +## **Summary** + +Recommendation ITU-T Y.2222 provides an introduction to sensor control networks (SCNs) and related applications in a next generation network (NGN) environment. More specifically, it provides an overview of SCNs, configurations for SCN applications and service requirements of SCN applications for support in a NGN environment. + +## **History** + +| Edition | Recommendation | Approval | Study Group | +|---------|----------------|------------|-------------| +| 1.0 | ITU-T Y.2222 | 2013-04-13 | 13 | + +## **Keywords** + +Actuator, configurations for SCN applications, decision-making process, emergency management, gate, mote, NGN, SCN, SCN applications, SCN controller, sensor control networks, sensor networks, verification application. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2014 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | | Page | +|---|------------------------------------------------------------------------------|------| +| 1 | Scope ..... | 1 | +| 2 | References..... | 1 | +| 3 | Definitions ..... | 1 | +| | 3.1 Terms defined elsewhere..... | 1 | +| | 3.2 Terms defined in this Recommendation..... | 2 | +| 4 | Abbreviations and acronyms ..... | 3 | +| 5 | Conventions ..... | 3 | +| 6 | Overview of SCNs..... | 4 | +| 7 | Configurations for SCN applications..... | 6 | +| | 7.1 Basic operations for SCN applications..... | 6 | +| | 7.2 Decentralized configuration for SCN applications..... | 7 | +| | 7.3 Transitional configurations for SCN applications..... | 9 | +| 8 | Service requirements of SCN applications ..... | 12 | +| | 8.1 Connectivity ..... | 12 | +| | 8.2 Mobility support ..... | 12 | +| | 8.3 Context awareness ..... | 13 | +| | 8.4 Location awareness ..... | 13 | +| | 8.5 Presence awareness ..... | 13 | +| | 8.6 Traffic and load awareness ..... | 14 | +| | 8.7 Fault awareness ..... | 14 | +| | 8.8 Routing ..... | 14 | +| | 8.9 Load balancing ..... | 14 | +| | 8.10 Scalability ..... | 14 | +| | 8.11 Fault tolerance ..... | 14 | +| | 8.12 Quality of service (QoS)..... | 14 | +| | 8.13 Management ..... | 15 | +| | 8.14 Pledging of security of decisions..... | 15 | +| | 8.15 Open service environment (OSE) support..... | 15 | +| | 8.16 NGN service integration and delivery environment (NGN-SIDE) support ... | 16 | +| | 8.17 Mass mobile user terminal support..... | 16 | +| | 8.18 Emergency management applications ..... | 16 | +| 9 | Security considerations ..... | 16 | +| | Appendix I – Use case of SCN for verification ..... | 17 | +| | I.1 Errors in decisions ..... | 17 | +| | I.2 Verification..... | 17 | +| | I.3 Examples of verification applications ..... | 19 | +| | Appendix II – Use case of SCN for emergency management ..... | 20 | + +| | Page | +|-------------------|-------------| +| Bibliography..... | 22 | + +# Recommendation ITU-T Y.2222 + +# Sensor control networks and related applications in a next generation network environment + +# 1 Scope + +This Recommendation provides an introduction to sensor control networks (SCNs) and related applications in a next generation network (NGN) environment. More specifically, this Recommendation provides: + +- definitions of SCN and SCN related terms; +- overview of SCNs; +- description of possible configurations for SCN applications and the decision-making process for these configurations; +- service requirements of SCN applications for support in NGN environment. + +Moreover, two important use cases of SCNs are described in the appendices: SCNs for verification and SCNs for emergency management. + +Business models and charging issues are outside of the scope of this Recommendation. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- | | | +|----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| [ITU-T Y.2020] | Recommendation ITU-T Y.2020 (2011), Open service environment functional architecture for next generation networks . | +| [ITU-T Y.2061] | Recommendation ITU-T Y.2061 (2012), Requirements for the support of machine-oriented communication applications in the next generation network environment . | +| [ITU-T Y.2234] | Recommendation ITU-T Y.2234 (2008), Open service environment capabilities for NGN . | +| [ITU-T Y.2240] | Recommendation ITU-T Y.2240 (2011), Requirements and capabilities for next generation network service integration and delivery environment . | + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 actuator** [ITU-T Y.2061]: A device performing physical actions caused by an input signal. + +NOTE 1 – As examples, an actuator might act on the flow of a gas or liquid, on electricity distribution, or through a mechanical operation. Dimmers and relays are examples of actuators. The decision to activate the actuator may come from an MOC application, a human or MOC devices and gateways. + +NOTE 2 (added by ITU-T Y.2222) – There are three types of actuators: information actuators, which are intended to provide visual, audio, sensory interaction with the human user; gateway actuators, which are intended to forward control commands given by SCN to other networks; machine actuators, which are electromechanical devices intended for physical interaction with the external environment. + +**3.1.2 application** [b-ITU-T Y.101]: A structured set of capabilities, which provide value-added functionality supported by one or more services. + +**3.1.3 context awareness** [b-ITU-T Y.2201]: A capability to determine or influence a next action in telecommunication or process by referring to the status of relevant entities, which form a coherent environment as a context. + +**3.1.4 machine oriented communication (MOC)** [ITU-T Y.2061]: A form of data communication between two or more entities in which at least one entity does not necessarily require human interaction or intervention in the communication process. + +**3.1.5 next generation network (NGN)** [b-ITU-T Y.2001]: A packet-based network able to provide telecommunication1 services and able to make use of multiple broadband, QoS-enabled transport technologies and in which service-related functions are independent from underlying transport-related technologies. It enables unfettered access for users to networks and to competing service providers and/or services of their choice. It supports generalized mobility which will allow consistent and ubiquitous provision of services to users. + +**3.1.6 NGN service integration and delivery environment (NGN-SIDE)** [ITU-T Y.2240]: An open environment in NGN integrating resources from different domains and delivering integrated services to applications over NGN. + +NOTE – These domains include, but are not limited to, telecommunication domain (e.g., fixed and mobile networks), Internet domain, broadcasting domain and content provider domain. + +**3.1.7 nomadism** [b-ITU-T Q.1706]: The ability of the user to change their network access point on moving. When changing the network access point, the user's service session is completely stopped and then started again, i.e., there is no service continuity or hand-over used. It is assumed that normal usage pattern is that users shut down their service session before attaching to a different access point. + +**3.1.8 open service environment capabilities** [ITU-T Y.2234]: Capabilities provided by open service environment to enable enhanced and flexible service creation and provisioning based on the use of standards interfaces. + +**3.1.9 seamless handover** [b-ITU-T Q.1706]: It is a special case of mobility with service continuity since it preserves the ability to provide services without any impact on their service level agreements to a moving object during and after movement. + +**3.1.10 sensed data** [b-ITU-T F.744]: Data sensed by a sensor that is attached to a specific sensor node. + +**3.1.11 sensor** [b-ITU-T Y.2221]: An electronic device that senses a physical condition or chemical compound and delivers an electronic signal proportional to the observed characteristic. + +**3.1.12 service** [b-ITU-T Y.101]: A structure set of capabilities intended to support applications. + +## **3.2 Terms defined in this Recommendation** + +This Recommendation defines the following terms: + +**3.2.1 aggregate value:** A value calculated by combining the sensed data of several spatially distributed nodes, reference values and other data and intended to represent the environmental conditions of a given geographical area. + +**3.2.2 central communication channel:** A communication channel or a set of communication channels for transmitting data between SCN controllers and actuators without utilizing nodes. + +**3.2.3 gate:** Intermediate device that is used to provide a communication channel between an actuator and one or several nearby motes. + +**3.2.4 mote:** A miniature computing device equipped with sensors and signal transceivers operating in a given radio band, and used for transmitting sensed data. + +NOTE 1 – It is a kind of sensor node and it is characterized by a mandatory minimal level of computing resources. + +NOTE 2 – Depending on application, a mote has one or more of the following capabilities: data manipulation, intelligent commutation and connectivity with actuators, retrieving data on the read-outs of near-site sensors. + +**3.2.5 mote group:** A set of motes connected to each other without making usage of external networks. + +**3.2.6 non-SCN-enabled actuator:** An actuator that is not able to communicate with motes directly, and uses networks to communicate with motes. + +NOTE – In this Recommendation, a non-SCN-enabled actuator uses NGN to communicate with motes. + +**3.2.7 reference value:** A value calculated by combining the sensed data of one or several closely situated motes and intended to represent the environmental conditions of some specific location. + +**3.2.8 sensor control network (SCN):** A sensor network consisting of motes which is intended for controlling one or more actuators. + +**3.2.9 SCN application:** An application that uses SCNs for controlling actuators. + +**3.2.10 SCN controller:** A hardware/software system designed to collect and process data from motes and to transmit to actuators the necessary information for their control. + +**3.2.11 SCN-enabled actuator:** An actuator that is able to communicate with motes directly. + +# 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|----------|--------------------------------------------------| +| 3G | Third Generation | +| GPRS | General Packet Radio Service | +| MOC | Machine Oriented Communication | +| NGN | Next Generation Network | +| NGN-SIDE | NGN Service Integration and Delivery Environment | +| OSE | Open Service Environment | +| PDA | Personal Digital Assistant | +| QoS | Quality of Service | +| SCN | Sensor Control Network | +| Wi-Fi | Wireless Fidelity | +| WiMAX | Worldwide Interoperability for Microwave Access | + +# 5 Conventions + +In this Recommendation: + +The keywords "is required to" indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this document is to be claimed. + +The keywords "is recommended" indicate a requirement which is recommended but which is not absolutely required. Thus this requirement need not be present to claim conformance. + +The keywords "can optionally" and "may" indicate an optional requirement which is permissible, without implying any sense of being recommended. These terms are not intended to imply that the vendor's implementation must provide the option and the feature can be optionally enabled by the network operator/service provider. Rather, it means the vendor may optionally provide the feature and still claim conformance with the specification. + +# **6 Overview of SCNs** + +Sensor networks are becoming more and more utilized and are under active development for different applications. These networks are frequently deployed with some control: sensor control networks (SCNs) are used to allow control by applications of the "actuators" which can be found in many sensor network deployments. The control is realized on a real-time basis and depending on environmental parameters. + +In SCNs, for the measurement of environmental parameters, motes are deployed and they can be seen as an evolutive version of sensors. In comparison with a sensor in a sensor network, a mote, besides physical conditions monitoring, can also have capabilities of data manipulation, intelligent commutation and connectivity to actuators. Motes are connected to NGN, by the use of a gateway or directly, and may also act as an access network to the SCN applications for actuators. + +NOTE 1 – The details of sensors and actuators are outside of the scope of this Recommendation. + +The goal of any application using SCNs ("SCN application") is to run a decision-making process and finally provide all involved actuators with relevant control commands. This process includes various activities of data acquisition, data transmission and data manipulation. A range of configurations (see details in clause 7) may be employed for SCN application's decision-making process depending on the capabilities of actuators and motes. For example, an actuator may only use commands provided by the SCN application to itself, or may customize them in order to meet its own capabilities and user requirements or may perform decision making completely by itself based on the data provided by the SCN application. + +Application field examples of SCNs include: + +- everyday life: navigation, excursions, sports; +- medicine: body control, e-health; +- enterprise: logistics, stock management; +- industrial field: fabrication automation, production process control; +- military field: combat assistance, remote piloting; +- emergency and disaster management: early warning, evacuation, emergency orchestration of civilians and rescuers, automatic danger elimination. + +The decisions of SCN applications may be targeted for both human users and control of machines (e.g., gears, vehicles, robots). The latter case also includes machine oriented communication (MOC) devices [ITU-T Y.2061] implying communications between two or more entities in which at least one entity does not necessarily require human interaction or intervention in the process of communication. + +Since decisions of SCN applications directly involve the operations of actuators, tight integration between SCN infrastructure and actuators' capabilities must be achieved. Although the following matter is outside of the scope of this Recommendation, it is expected that standardization of the interfaces between SCNs and actuators will be critical. + +In addition, although the following matter is also outside of the scope of this Recommendation and for further study, it is anticipated that some enhancements to the NGN capabilities + +[b-ITU-T Y.2201] will be required in order to support the service requirements of SCN applications identified in this Recommendation. + +Figure 6-1 shows an overview of SCNs, including SCN applications and the supporting role of NGN. + +![Figure 6-1: Overview of SCNs. The diagram illustrates the architecture of Smart Control Networks (SCNs) across four domains: NGN domain, SCN infrastructure domain, Actuator domain, and SCN application domain. The NGN domain at the top contains the NGN core network and NGN access network. The SCN infrastructure domain in the middle contains SCN controller(s) and Mote groups. The Actuator domain below that is divided into Non-SCN-enabled actuators (Machine, Gateway, and Information actuators) and SCN-enabled actuators (Machine, Gateway, and Information actuators). The SCN application domain at the bottom contains Emergency management applications, Verification applications, and Other applications. Physical connections are shown as solid lines, and logical connections are shown as dashed lines with double-headed arrows. A legend at the bottom indicates that solid lines represent physical connections and dashed lines with double-headed arrows represent logical connections.](e9314c83043183351ed74908e9bf2f90_img.jpg) + +Y.2222(13)\_F6-1 + +Figure 6-1: Overview of SCNs. The diagram illustrates the architecture of Smart Control Networks (SCNs) across four domains: NGN domain, SCN infrastructure domain, Actuator domain, and SCN application domain. The NGN domain at the top contains the NGN core network and NGN access network. The SCN infrastructure domain in the middle contains SCN controller(s) and Mote groups. The Actuator domain below that is divided into Non-SCN-enabled actuators (Machine, Gateway, and Information actuators) and SCN-enabled actuators (Machine, Gateway, and Information actuators). The SCN application domain at the bottom contains Emergency management applications, Verification applications, and Other applications. Physical connections are shown as solid lines, and logical connections are shown as dashed lines with double-headed arrows. A legend at the bottom indicates that solid lines represent physical connections and dashed lines with double-headed arrows represent logical connections. + +**Figure 6-1 – Overview of SCNs** + +Figure 6-1 depicts four domains: + +- 1) NGN domain: the connectivity via NGN fulfils two objectives. First, NGN provides access to SCN applications for both non-SCN-enabled and SCN-enabled actuators when direct communication of actuators with motes is not possible or desirable (e.g., when an actuator is a mobile phone and its owner does not want his/her location to be exposed due to privacy reasons). Second, NGN is used to unite spatially distributed mote groups and the SCN controllers into a single network. + +NOTE 2 – NGN is expected to provide the same capabilities (e.g., load balancing, fault tolerance) as a single mote group directly connected to the SCN controllers. + +- 2) SCN infrastructure domain: the SCN infrastructure includes one or several SCN controllers and mote groups. They may be spatially distributed: in that case, NGN is used to unite them into a single network. Authorized personnel may use the SCN controllers for SCN monitoring and administration. Motes can allow direct access to SCN applications of SCN-enabled actuators, while direct access via motes to SCN applications of non-SCN enabled actuators is not possible. The SCN controllers are connected to NGN directly. +- 3) Actuator domain: the actuators can be of three different types: machine actuators (e.g., car, water sprinkler, door lock), information actuators (e.g., screen, loudspeaker, mobile phone, PDA, notebook) and gateway actuators (e.g., computer with telephone private branch exchange software). + +NOTE 3 – The term "SCN objects" is used in the following clauses to cover motes and SCN controllers (which constitute the SCN infrastructure), as well as actuators. + +- 4) SCN application domain: consists of SCN applications, e.g., verification applications (see Appendix I), emergency management applications (see Appendix II) and others. + +NOTE 4 – Different parts of SCN applications can reside in different SCN objects according to the specific application requirements. + +# **7 Configurations for SCN applications** + +## **7.1 Basic operations for SCN applications** + +Four types of operations are identified for SCN applications: + +- 1) Fetching of sensed data (shown as Sensed data in Figures 7-1 to 7-5 and I.1). +- 2) Calculation of reference values by combining (e.g., averaging) the sensed data of one or several closely situated motes (shown as Reference values in Figures 7-1 to 7-5 and I.1). The aim of this process can be for example: + - comparison of sensed data readings with thresholds for the purpose of filtering sensed data and taking them into account during calculations of aggregate values and/or decision making, + - auxiliary pre-calculations for the purpose of quicker calculation of aggregate values and/or decision making, + - synchronous analysis of multiple sensed data readings. +- 3) Calculation of aggregate values by combining (e.g., averaging) the sensed data of several spatially distributed motes, reference values and other data (shown as Aggregate values in Figures 7-1 to 7-5 and I.1). +- 4) Decision making (shown as Decision making in Figures 7-1 to 7-5 and Figure I.1). During this process a specific control command for the actuator is formed. It can use fetched aggregate values. + +In SCNs, data can be transmitted via the SCN infrastructure (i.e., using motes and SCN controllers as intermediate nodes) and via the central communication channel (e.g., using GPRS/3G, Wi-Fi and WiMAX technologies). + +The above-described operations and the associated data transmissions can be represented in a flow chart. The rows of such a chart represent the above listed operations and the columns represent elements participating in the decision-making process. Data transmission flows are depicted as horizontal arrows whose endings correspond to the sending and receiving elements of the actual transmission stage, while data computational flows are depicted as vertical arrows corresponding to the above described operations. Figure 7-1 shows an example of such a flow chart. + +![Flow chart example of basic operations for a SCN application. The diagram shows a 4x4 grid with columns 'Motes', 'SCN controllers', and 'Actuators', and rows 'Decision making', 'Aggregate values', 'Reference values', and 'Sensed data'. Arrows indicate the flow of data: from 'Sensed data' to 'Reference values' (vertical), from 'Reference values' to 'SCN controllers' (horizontal), from 'SCN controllers' to 'Aggregate values' (vertical), from 'Aggregate values' to 'Actuators' (horizontal), and from 'Actuators' to 'Decision making' (vertical).](af7916c89a458fdab6c3f443217388ae_img.jpg) + +| | Motes | SCN controllers | Actuators | +|------------------|-------|-----------------|-----------| +| Decision making | | | | +| Aggregate values | | | | +| Reference values | | | | +| Sensed data | | | | + +Flow chart example of basic operations for a SCN application. The diagram shows a 4x4 grid with columns 'Motes', 'SCN controllers', and 'Actuators', and rows 'Decision making', 'Aggregate values', 'Reference values', and 'Sensed data'. Arrows indicate the flow of data: from 'Sensed data' to 'Reference values' (vertical), from 'Reference values' to 'SCN controllers' (horizontal), from 'SCN controllers' to 'Aggregate values' (vertical), from 'Aggregate values' to 'Actuators' (horizontal), and from 'Actuators' to 'Decision making' (vertical). + +Y.2222(13)\_F7-1 + +**Figure 7-1 – Flow chart example of basic operations for a SCN application** + +## **7.2 Decentralized configuration for SCN applications** + +#### **7.2.1 Introduction to decentralized configuration for SCN applications** + +The decentralized configuration is the most universal configuration for SCN applications in terms of flexibility, expansibility and reliability. It is so called because it makes minimal demand to the central communication channel and the SCN controllers. This provides the possibility of ubiquitous usage of such configurations in a wide range of applications, including emergency management applications (due to the high risk of failure related to centralized entities in case of disaster or emergency). + +#### **7.2.2 Role distribution in decentralized configuration for SCN applications** + +- **SCN controller:** + - It receives from the actuators via the central communication channel requests about aggregate values, which are necessary for making decision but cannot be calculated by the actuators themselves. + - It requests transmission of sensed data and reference values from the appropriate motes via the SCN infrastructure and regularly calculates the necessary aggregate values. + - It transmits to each actuator via the central communication channel the aggregate values requested by that actuator. + - It interoperates with external systems (e.g., a different application server) and the authorized personnel administrating the SCN. +- **Actuator:** + - It requests the necessary sensed data and reference values from the motes via the SCN infrastructure. + - It requests from the SCN controllers via the central communication channel the aggregate values which are necessary for decision making but cannot be calculated by the actuator itself. + - It receives from the motes via the SCN infrastructure the requested sensed data and reference values and calculates the other necessary reference values and aggregate values. + - It receives from the SCN controllers via the central communication channel the requested aggregate values. + - It forms the appropriate control commands. + +- It transmits to the SCN controllers information about its own status via the central communication channel. +- **Mote:** +- It receives requests from the SCN controllers and the actuators via the SCN infrastructure about sensed data or reference values. +- It transmits the requested data to the SCN controllers and the actuators via the SCN infrastructure. + +#### 7.2.3 Decision-making process + +The decision-making process follows the following procedure: + +- 1) The necessary sensed data, reference values and aggregate values are kept in the SCN controllers' memory and regularly updated. +- 2) Each actuator sends requests for sensed data and reference values to the motes, and then stores the received ones in memory. The data requests can be of different types, such as broadcast requests (all motes send data on demand to actuators via the SCN infrastructure), or threshold-exceeding requests (only motes whose sensed data exceed some thresholds send data), etc. +- 3) Some other reference values can be computed as needed by the actuators based on received sensed data and reference values. +- 4) Each actuator needs to have the up-to-date aggregate values necessary to make a decision. These aggregate values can be computed by the actuator itself or fetched from the SCN controllers. +- 5) Each actuator forms a control command depending on the aggregate values. + +Two examples of flow charts for decentralized configuration are shown in Figures 7-2 and 7-3. + +In the first example, actuators use aggregate values received from the SCN controllers (data flow 2) and aggregate values calculated using reference values received from motes (data flow 1). + +In the second example, actuators use only aggregate values calculated using reference values received from motes (data flow 1). There is no influence of the SCN controllers on the decision-making process. The SCN controllers only calculate (data flow 2) and store in memory aggregate values for the purpose of interoperation with external systems and the authorized personnel administrating the SCN. + +![Flow chart for decentralized configuration for SCN applications. The diagram shows four rows representing data types: Decision making, Aggregate values, Reference values, and Sensed data. The columns represent the entities: Motes, SCN controllers, and Actuators. Arrows indicate the direction of data flow, with labels (1) and (2) identifying specific data flows. (1) represents the flow from Motes to Actuators via Reference values. (2) represents the flow from Motes to SCN controllers via Sensed data, and from SCN controllers to Actuators via Aggregate values.](16c1175b5f05a4b55e6d396fc51b15b3_img.jpg) + +| | Motes | SCN controllers | Actuators | +|------------------|-------|-----------------|-------------| +| Decision making | | | ↑ (1) | +| Aggregate values | | ↑ (2) | → (2) ↑ (1) | +| Reference values | ↑ (1) | → (2) | → (1) | +| Sensed data | → (2) | | | + +Flow chart for decentralized configuration for SCN applications. The diagram shows four rows representing data types: Decision making, Aggregate values, Reference values, and Sensed data. The columns represent the entities: Motes, SCN controllers, and Actuators. Arrows indicate the direction of data flow, with labels (1) and (2) identifying specific data flows. (1) represents the flow from Motes to Actuators via Reference values. (2) represents the flow from Motes to SCN controllers via Sensed data, and from SCN controllers to Actuators via Aggregate values. + +Y.2222(13)\_F7-2 + +**Figure 7-2 – A first example of a flow chart for decentralized configuration for SCN applications** + +![Flow chart for decentralized configuration for SCN applications. The diagram shows a 4x4 grid with columns: Motes, SCN controllers, and Actuators. Rows represent functional blocks: Decision making, Aggregate values, Reference values, and Sensed data. Arrows indicate data flow: (1) from Actuators to Decision making; (1) from Actuators to Aggregate values; (1) from Actuators to Reference values; (1) from Sensed data to Actuators; (2) from Motes to SCN controllers; (2) from SCN controllers to Aggregate values; (2) from SCN controllers to Reference values; (2) from Sensed data to SCN controllers.](33ed1f9b27c7c21c797aa928b0f06851_img.jpg) + +| | Motes | SCN controllers | Actuators | +|------------------|-------|-----------------|-----------| +| Decision making | | | ↑ (1) | +| Aggregate values | | ↑ (2) | ↑ (1) | +| Reference values | | ↑ (2) | ↑ (1) | +| Sensed data | → | ↑ (2) | ↑ (1) | + +Flow chart for decentralized configuration for SCN applications. The diagram shows a 4x4 grid with columns: Motes, SCN controllers, and Actuators. Rows represent functional blocks: Decision making, Aggregate values, Reference values, and Sensed data. Arrows indicate data flow: (1) from Actuators to Decision making; (1) from Actuators to Aggregate values; (1) from Actuators to Reference values; (1) from Sensed data to Actuators; (2) from Motes to SCN controllers; (2) from SCN controllers to Aggregate values; (2) from SCN controllers to Reference values; (2) from Sensed data to SCN controllers. + +Y.2222(13)\_F7-3 + +**Figure 7-3 – A second example of a flow chart for decentralized configuration for SCN applications** + +## 7.3 Transitional configurations for SCN applications + +Nowadays most mass mobile user terminals, such as mobile phones, PDAs and netbooks, have no technical possibility of direct data exchange with existing infrastructures of motes because of differences in transceiver types and transmission standards. Therefore, transitional configurations are needed to provide a possibility of using SCNs with mass mobile user terminals. + +#### 7.3.1 Centralized configuration for SCN applications + +##### 7.3.1.1 Introduction to centralized configuration for SCN applications + +This configuration is so called because the data for every decision made by SCN are transferred through the SCN controllers and are delivered to the actuators via a central communication channel. It should be employed when actuators can only communicate via the central communication channel and/or it is not desirable to change the existing infrastructure of motes and actuators to enable SCN applications. + +##### 7.3.1.2 Role distribution in a centralized configuration for SCN applications + +- **SCN controller:** + - It receives from the actuators requests via the central communication channel about aggregate values. + - It requests transmission of sensed data and reference values from the appropriate motes via the SCN infrastructure and regularly calculates the necessary aggregate values. + - It transmits to each actuator via the central communication channel the aggregate values requested by that actuator. + - It interoperates with external systems (e.g., a different application server) and the authorized personnel administrating the SCN. +- **Actuator:** + - It requests from the SCN controllers via the central communication channel aggregate values, which are necessary for making a decision. + - It receives from the SCN controllers via the central communication channel the requested aggregate values. + - It forms the appropriate control commands. + +- It transmits information about its own status to the SCN controllers via the central communication channel. +- **Note:** +- It receives requests from the SCN controllers via the SCN infrastructure about sensed data or reference values. +- It transmits to the SCN controllers the requested data via the SCN infrastructure. + +#### 7.3.1.3 Decision-making process + +The decision-making process follows the following procedure: + +- 1) The necessary sensed data, reference values and aggregate values are kept in the SCN controllers' memory and regularly updated. +- 2) Each actuator needs to have the up-to-date aggregate values necessary to make a decision. These aggregate values are fetched from the SCN controllers. +- 3) Each actuator forms a control command depending on the aggregate values. + +An example of a flow chart for centralized configuration is shown in Figure 7-4. + +![Flow chart for centralized configuration showing data flow between Motes, SCN controllers, and Actuators. Sensed data and reference values flow from Motes to SCN controllers. Aggregate values flow from SCN controllers to Actuators. Decision making occurs at the Actuators.](a83ba9e3e2c1e21dd69953a7b09e45b4_img.jpg) + +| | Motes | SCN controllers | Actuators | +|------------------|-------|-----------------|-----------| +| Decision making | | | ↑ | +| Aggregate values | | ↑ | ← | +| Reference values | ← | ↑ | | +| Sensed data | ← | ↑ | | + +Flow chart for centralized configuration showing data flow between Motes, SCN controllers, and Actuators. Sensed data and reference values flow from Motes to SCN controllers. Aggregate values flow from SCN controllers to Actuators. Decision making occurs at the Actuators. + +Y.2222(13)\_F7-4 + +**Figure 7-4 – Example of flow chart for centralized configuration for SCN applications** + +#### 7.3.2 Ad-hoc configuration for SCN applications + +#### 7.3.2.1 Introduction to ad-hoc configuration for SCN applications + +This configuration is so called because it utilizes ad-hoc networks (e.g., based on Bluetooth or Wi-Fi technologies) to deliver data to actuators. It should be employed when there is the possibility to expand the existing SCN infrastructure and the actuators have some ad-hoc wireless network capabilities. Some intermediate devices called gates are used to provide a communication channel between actuators and one or several nearby motes. + +#### 7.3.2.2 Role distribution in ad-hoc configuration for SCN applications + +- **SCN controller:** +- It receives from the actuators via the central communication channel requests about aggregate values, which are necessary for making a decision but cannot be calculated by the actuators themselves. +- It requests transmission of sensed data and reference values from the appropriate motes and regularly calculates the necessary aggregate values. + +- It transmits to each actuator via the central communication channel the aggregate values requested by that actuator. +- It interoperates with external systems (for example, a different application server) and the authorized personnel administrating the SCN. +- **Gate:** + - It receives requests from the actuators via the ad-hoc network about sensed data and reference values and forwards them to the motes via the SCN infrastructure. + - It transmits the requested data to the actuators via the ad-hoc network. +- **Actuator:** + - It requests the necessary sensed data and reference values from the gates via the ad-hoc network. + - It requests from the SCN controllers via the central communication channel aggregate values, which are necessary for a decision but cannot be calculated by the actuator itself. + - It receives from the gates via the ad-hoc network the requested sensed data and reference values and calculates the other necessary reference values and aggregate values. + - It receives from the SCN controllers via the central communication channel the requested aggregate values. + - It forms the appropriate control commands. + - It transmits to the SCN controllers information about its own status via the central communication channel. +- **Note:** + - It receives requests from the SCN controllers and the gates via the SCN infrastructure about sensed data or reference values. + - It transmits the requested data to the SCN controllers and the gates via the SCN infrastructure. + +#### 7.3.2.3 Decision-making process + +The decision-making process follows the following procedure: + +- 1) The necessary sensed data, reference values and aggregated values are kept in the SCN controllers' memory and regularly updated. +- 2) Each gate forwards sensed data and reference values from the motes to the actuators. +- 3) Each actuator sends requests for sensed data and reference values to the gates, and then stores the received ones in memory. The data requests can be of different types, such as broadcast request (the gates send data of all motes on demand to the actuator), threshold-exceeding request (gates send data only of the motes whose sensed data exceed some thresholds), etc. +- 4) Some other reference values can be regularly computed as needed by the actuators based on received sensed data and reference values. +- 5) Each actuator needs to have the up-to-date aggregate values necessary to make a decision. These aggregate values can be computed by the actuator itself or fetched from the SCN controllers. +- 6) Each actuator forms a control command depending on the aggregate values. + +An example of flow chart for ad-hoc configuration is shown in Figure 7-5. + +![Flow chart for ad-hoc configuration for SCN applications. The diagram shows data flow between four components: Motes, Gates, SCN controllers, and Actuators across four functional layers: Sensed data, Reference values, Aggregate values, and Decision making. Arrows indicate the direction of data flow: Sensed data flows from Motes to Gates and then to SCN controllers; Reference values flow from Motes to Gates, then to SCN controllers, and finally to Actuators; Aggregate values flow from SCN controllers to Actuators; and Decision making flows from Actuators back to SCN controllers.](76b0cd79baaedd942af4dc42f2e764b8_img.jpg) + +| | Motes | Gates | SCN controllers | Actuators | +|------------------|-------|-------|-----------------|-----------| +| Decision making | | | | | +| Aggregate values | | | | | +| Reference values | | | | | +| Sensed data | | | | | + +Flow chart for ad-hoc configuration for SCN applications. The diagram shows data flow between four components: Motes, Gates, SCN controllers, and Actuators across four functional layers: Sensed data, Reference values, Aggregate values, and Decision making. Arrows indicate the direction of data flow: Sensed data flows from Motes to Gates and then to SCN controllers; Reference values flow from Motes to Gates, then to SCN controllers, and finally to Actuators; Aggregate values flow from SCN controllers to Actuators; and Decision making flows from Actuators back to SCN controllers. + +Y.2222(13)\_F7-5 + +**Figure 7-5 – Example of flow chart for ad-hoc configuration for SCN applications** + +# 8 Service requirements of SCN applications + +The followings are high-level service requirements of SCN applications. + +## 8.1 Connectivity + +- 1) SCN applications are required to support three types of communications: + - SCN controller-actuator communication: actuators communicate with the SCN controllers; + - Infrastructure communication (including one-to-one, one-to-many, many-to-one and many-to-many): motes from different mote groups communicate with each other and with the SCN controllers; + - SCN controller-NGN communication: NGN elements communicate with the SCN controllers. +- 2) SCN applications are recommended to support the following type of communications: + - Mote-actuator communication (including one-to-one, one-to-many and optionally many-to-one and many-to-many): actuators communicate with motes. +- 3) SCN applications can optionally provide these types of communications: + - Inter-actuator communication: actuators communicate with each other; + - Actuator-NGN communication: NGN elements communicate with actuators; + - Mote-NGN communication: NGN elements communicate with motes. + +## 8.2 Mobility support + +Actuators as well as motes can be classified as follows: + +- Network-specific actuators and motes, designed to operate in specific SCN application fields (e.g., complex industrial mechanisms); +- Mission-specific actuators and motes, designed to be deployed after preliminary setup (e.g., mass-produced switches); +- Generic actuators and motes, designed to be instantly deployed and used in a wide range of SCN applications (e.g., PDAs). + +SCN applications have the following general requirements concerning mobility: + +- 1) SCN applications are required to support nomadism for mission-specific and generic actuators and motes. +- 2) SCN applications are recommended to support seamless handover for generic actuators and motes. + +## **8.3 Context awareness** + +Context information can have a great effect on the decision-making process. Examples of context information elements include the following: + +- Capabilities of SCN objects; +- Location of actuators and motes; +- Presence and operational status of actuators and motes; +- Traffic load and computational load of SCN objects; +- Information about faults of SCN objects. + +SCN applications have the following general requirements concerning context-awareness: + +- 1) Context information is required to be collected and distributed to any interested SCN object. +- 2) Delays in context information updates are required to be minimized so that the reliability of the decision making is not decreased significantly. + +NOTE – Requirements specific to some context-related aspects are given in other specific clauses. + +## **8.4 Location awareness** + +Location information needs to be maintained and managed in order to support context awareness with location information for SCN applications. Management can be in static or dynamic conditions of the located entities. In addition, SCN application service and device discovery can be facilitated by the usage of the location information. Thus, SCN applications have the following requirements: + +- 1) Location information of mote groups is recommended to be managed for SCN applications. +- 2) Location information of actuators is recommended to be managed for SCN applications. +- 3) Location information of individual mote can be optionally managed for SCN applications when the location information of a single mote is useful. + +## **8.5 Presence awareness** + +Presence information includes the network-related part of presence information (e.g., concerning connectivity and willingness to communicate) and the operation-related part of presence information (e.g., concerning workability and currently performing operation). SCN applications have the following requirements: + +- 1) The network-related part of presence information is required to be managed for SCN applications. +- 2) The operation-related part of presence information is recommended to be managed for SCN applications. + +## **8.6 Traffic and load awareness** + +To realize traffic and load optimization, SCN applications have the following requirements: + +- 1) Information related to traffic and computational capabilities of SCN objects is recommended to be registered for SCN applications. +- 2) Information about current traffic and computational load is recommended to be managed for SCN applications. + +## **8.7 Fault awareness** + +A SCN needs to react to the failure of any SCN objects in order to provide reliability and availability. + +- 1) Information about SCN object faults is required to be managed for SCN applications. + +## **8.8 Routing** + +- 1) SCN applications are required to support routing using distributed mechanisms, such as those based upon peer-to-peer (P2P) techniques. +- 2) SCN applications are recommended to identify the preferred path between any pair of SCN objects. The path selection can be based on historical data or on real-time data to reflect the traffic congestion situation between those SCN objects. + +## **8.9 Load balancing** + +- 1) SCN applications are required to dynamically balance the traffic load of SCN objects, based on the status and/or capabilities of SCN objects, traffic balancing policy, etc. + +## **8.10 Scalability** + +- 1) SCN applications are required to offer scalability by using P2P and/or other distributed mechanisms, so that the capacity of the SCN infrastructure to provide services to users is proportional, or nearly proportional, to the number of the motes and actuators. + +## **8.11 Fault tolerance** + +- 1) SCN applications are required to ensure reliability and availability of the SCN infrastructure in order to handle a single mote failure and a mote group failure. +- 2) SCN applications are recommended to ensure reliability and availability of the SCN infrastructure in the case of failure of the SCN controllers. + +NOTE – In the case of these failures, the capabilities of the failed SCN object(s) can be dynamically replaced by those of other SCN objects to provide consistent service to end users. + +## **8.12 Quality of service (QoS)** + +Different SCN applications may have different QoS requirements. For example, data transmission in verification applications may require much lower delays than in other SCN applications. + +- 1) SCN applications are recommended to support QoS differentiation according to the required service level quality. +- 2) It is required that the traffic volume generated by SCN applications be managed. +- 3) It is recommended that SCN applications avoid access concentration in a single SCN controller or a single mote. +- 4) It is recommended that specific QoS support for emergency applications be provided. + +NOTE 1 – Clause 8.18 provides further information and requirements about emergency applications in SCNs. + +- 5) It is recommended that specific QoS applications intended for pledging of security of decisions be provided. + +NOTE 2 – Clause 8.14 provides further information and requirements about pledging of security of decisions. + +## **8.13 Management** + +- 1) SCN applications are required to allow the user to enable and disable the provided services. +- 2) SCN applications are required to allow the user to apply different policies concerning allowing and denying specific commands to actuators. +- 3) SCN applications are recommended to provide the user with the ability to personalize the services. + +## **8.14 Pledging of security of decisions** + +The decision-making process in SCN applications includes different activities on different SCN objects and can be very complicated. As a result, there are a number of sources of errors in decisions including erroneous, outdated, incomplete data and object synchronization errors. Some erroneous decisions of SCN applications can entail considerable negative consequences. + +- 1) SCN applications are required to provide measures to avoid considerable negative consequences of their decisions on condition that all the actuators carry out commands given by the SCN applications exactly. +- 2) SCN applications are required to provide all the necessary measures to identify the party responsible for erroneous decision operations entailing considerable negative consequences. +- 3) SCN applications are required to provide operational logging sufficient to determine the source of errors entailing considerable negative consequences. + +## **8.15 Open service environment (OSE) support** + +SCN applications can optionally support open service environment (OSE) capabilities as described in [ITU-T Y.2020] and [ITU-T Y.2234]. + +In case of SCN applications' support of OSE capabilities, SCN applications, services, actuators, motes and mote groups are recommended to be registered beforehand in order to enable the ability to be discovered (by specifying one or more related attributes). + +It may be desirable for the user to use the same application in different SCN infrastructures. As the user changes his location and moves to another SCN infrastructure, service discovery is automatically started to check if that SCN infrastructure provides the required services. If these services are not registered, the SCN application may try to use a service composition procedure to create the required services from other existing services based on the capabilities of the SCN infrastructure. A service description language and its associated execution framework are recommended to be provided to support service registration, discovery and composition. + +The following requirements are identified in the case of SCN applications' support of OSE capabilities: + +- 1) It is recommended to support registration and discovery of SCN applications, services, actuators, motes and mote groups. +- 2) It is recommended to support at least one service description language and its associated execution framework. +- 3) Automatic service discovery and service composition can be optionally supported. + +## **8.16 NGN service integration and delivery environment (NGN-SIDE) support** + +SCN applications can optionally support next generation network service integration and delivery environment (NGN-SIDE) capabilities [ITU-T Y.2240]. + +The SCN objects can be integrated with resources from different domains (e.g., telecommunication domain (fixed and mobile networks), broadcasting domain, Internet domain or content provider domain) over NGN with the use of NGN-SIDE. + +From this point of view, the SCN objects can be considered as resources, and NGN-SIDE acts as a mediator between these resources and SCN applications. More specifically, the NGN-SIDE adaptation layer adapts the resources offered by the SCN objects in order to provide uniformly adapted resources (e.g., control and media format) for interaction with the NGN-SIDE integration layer as described in [ITU-T Y.2240]. The NGN-SIDE adaptation layer provides adaptation capabilities, called adaptors, hiding the details of the resources offered by the SCN objects. + +The following requirement is identified in the case of SCN applications' support of NGN-SIDE capabilities: + +- 1) SCN applications are required to access SCN objects through adaptors. + +## **8.17 Mass mobile user terminal support** + +Most of the mass mobile user terminals have no technical possibility of direct data exchange with an existing infrastructure of motes. However, it is generally desirable to offer SCN applications to the users of these terminals because of their prevalence and considerable communication and computing capabilities. SCN applications may provide connectivity with such terminals using available communication technologies (e.g., Bluetooth, GPRS/3G, Wi-Fi, WiMAX). + +- 1) SCN applications can optionally support the mass mobile user terminals including the terminals that are not specifically intended for SCN applications. + +## **8.18 Emergency management applications** + +Some SCN applications provide support for early-warning emergency enhanced by recommendations about the escape from emergency situations based on the features of user location awareness and service personalization according to users' medical peculiarities or duties. + +- 1) SCN applications for emergency management are recommended to be supported by the SCN objects. + +# **9 Security considerations** + +SCN applications are required to support the integrity and confidentiality of the data exchanged during the application operations. + +SCN applications are required to provide security for exchanged data against malicious attacks. + +SCN applications are required to authenticate motes and mote groups to prevent compromising of sensed data. + +It is recommended to provide a secure channel to protect the sensed data among SCN objects. + +NOTE – Detailed security requirements for SCN applications are outside of the scope of this Recommendation. + +# Appendix I + +## Use case of SCN for verification + +(This appendix does not form an integral part of this Recommendation.) + +### I.1 Errors in decisions + +The decision-making process in SCN applications includes different activities and can be very complicated. As a result, there is a whole series of sources of errors in decisions: + +- Unreliability of communication channels. Normally, SCN applications intend to make wide usage of wireless communications which are more error-prone in comparison with wired communications. +- Distributed calculation model. This model makes it difficult to synchronize all the activities and to provide all the SCN objects with actual data. +- Not very predictable duration of the decision-making process, due to different delays in calculations and data transmissions. +- Mobility of actuators and possibility of their usage for different SCN applications. When this is accompanied by the presence of several software and hardware vendors of actuators, this feature deprives the system designer of the possibility to test the system thoroughly in various conditions. Furthermore, when the interaction of the actuator with the SCN infrastructure is not on a systematic basis, making critical decisions cannot be entrusted entirely. +- Hardware and software errors. + +As a result, control commands given by SCN applications should be analysed in order to ensure that possible errors do not result in considerable negative consequences. When a control command is intended for an information actuator, it can be analysed by the human who receives the control command. When a control command is forwarded to another network by a gateway actuator, the duty of analysis shifts onto the other network. But when a control command should be carried out without any direct human intervention to a machine actuator, special measures should be taken to counteract errors in decisions made by SCN applications. + +### I.2 Verification + +For a machine actuator, there is a set of critical operations which can lead to considerable negative consequences when carried out in an improper system state. To avoid this, for each critical operation, a set of rules should be defined, which must be checked before this operation and/or while the operation is in progress. These rules are called "verification rules". To check the verification rules, a number of values of different types must be determined: + +- Aggregate values, reference values, sensed data obtained in SCN application as part of normal flow of decision making. +- Aggregate values, reference values, sensed data obtained in SCN application which are only intended to support verification. +- Sensed data obtained from sensors associated with machine actuators. +- Values obtained upon request from SCN controllers or NGN entities. + +In order to provide verification applications, verification networks are used. A verification network consists of devices and communication channels which are used to fetch and process the above described values. A verification network can have some elements which are also SCN objects or that constitute a part of the SCN infrastructure. A verification network may have much more strict requirements concerning reliability, security and performance compared to other SCN applications. + +Data processing and transmission for the purpose of verification may have higher priority in QoS in comparison with other operations of SCN applications. + +Examples of operations which require verification, verification rules and verification network elements are given below. + +The operations in a verification network can be executed once before critical operations of SCN applications, or at the time of these operations or periodically. For each possible machine actuator state and detected verification rule failure, some operations should be defined to be performed instead of those given by the SCN application when one of the verification rules is mismatched. Such operations can be, for example: + +- Immediate machine actuator stop. +- State transition of the machine actuator to some safe state. +- Alarm notification to authorized personnel administrating the SCN. +- Generation of a log entry. +- No action. + +An example of flow chart for the decision-making process in verification networks can be depicted as in Figure I.1. + +![Figure I.1: Decision-making process in verification networks. A flowchart showing the process flow between Sensed data, Reference values, Aggregate values, Decision making, and Decision verification, leading to either Normal decision or Safe operation.](7e1c9b51e067a48cd0fcc9748d8bd8d8_img.jpg) + +| | Motes | SCN controllers | Actuators | Verification network | +|-----------------------|-------|-----------------|-----------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Decision verification | | | |
→
→
| +| Decision making | | | | | +| Aggregate values | | | | | +| Reference values | | | | | +| Sensed data | | | | | + +Y.2222(13)\_Fl.1 + +Figure I.1: Decision-making process in verification networks. A flowchart showing the process flow between Sensed data, Reference values, Aggregate values, Decision making, and Decision verification, leading to either Normal decision or Safe operation. + +**Figure I.1 – Decision-making process in verification networks** + +The figure depicts a normal decision-making flow, but because the decision involves a machine actuator, the verification process is initiated by the verification network. + +If some of the checks of the verification process fail, some safe operation (or no action) is performed instead of normal decision. + +### **I.3 Examples of verification applications** + +#### **I.3.1 Fire safety system** + +A fire safety system is deployed in a building. If one of its sensors detects ignition or smoke, it activates machine actuators that lock doors and windows to prevent air circulation. The considerable negative consequences include people being locked inside the rooms and people being crushed by automatic doors. + +Therefore, the verification network should consist of: + +- sensors of movement in rooms; +- light sensors between door wings, and strain sensors on the motors of door wings to halt the motors if there is a person between the door wings. + +#### **I.3.2 On-road speed control** + +Sensors are used to monitor road conditions. Vehicles are equipped with actuators able to communicate with sensors which can automatically decrease the vehicle speed if the road conditions are dangerous. + +A possible relevant negative consequence is that if the speed decrease is too fast, chances of collision with vehicles behind can happen. To prevent this result, the verification network should use a rear parking sensor that can monitor the free space behind the vehicle and slow the rate of speed decrease if there is another vehicle nearby. + +#### **I.3.2 Rescue robots** + +After a plane crash, rescuers use autonomous robots to retrieve survivors from under the wreckage. These robots pick up wreckage fragments and move them to a safe place. + +If a robot runs out of energy after it has picked up a heavy fragment, it could drop it on the injured human or rescuers, causing therefore relevant negative consequences. The verification network should be based on energy sensors and on robot's CPU. The latter should be able to estimate the weight of the fragment to be picked up and the amount of energy required. If the robot's energy level is not sufficient, the operation must be blocked. + +# Appendix II + +## Use case of SCN for emergency management + +(This appendix does not form an integral part of this Recommendation.) + +An emergency management system [b-ITU News] uses motes to observe the physical conditions of a building (temperature, smoke, etc.). At the entrance to the building, a mobile user terminal (e.g., phone, PDAs or tablet PC) automatically connects to the SCN infrastructure and obtains data from the motes. + +An emergency management system automatically detects emergency situations. In this case, the user equipment launches software for guidance in emergency cases. It gives instructions on how to leave the building in the safest way, for example: + +- evacuation plans or maps; +- step-by-step sound commands and visual hints (e.g., interior photos with overlaid arrows towards the exit); +- videos showing how to use safety equipment. + +The content of these instructions depends on various factors, for example: + +- state of building detected by motes like accessibility and hazard level of rooms and escape routes; +- position of the user determined by the nearest network node or using GPS; +- user's state of health determined by e-health equipment. + +In addition, special information containing both needs and duties is taken into account by the system. It may be limitations of motion and senses for disabled people that influence the route choice. At the same time, special personnel of the building may need specific instructions concerning their service duties (for example, emergency case specialists at the time of an accident at a nuclear power plant). + +In-building actuators (e.g., door openers, emergency lightning and sprinklers) also get commands from the system and start working. + +The emergency operation centre and/or emergency services also get information about the emergency including its type and place of origin. + +If the motes detect no emergency situations, energy consumption of the system should be minimized. The system should be optimized for low traffic. Motes and mobile user terminals may be sleeping most of the time or be used for other applications. However, as an emergency situation is detected, the system must switch to special mode in order to rescue people as soon as possible (15 minutes or less), e.g.,: + +- all the motes and mobile user terminals should be awakened from sleep; +- traffic not related to rescue should be discarded to provide low latency and high transmission rate; +- software applications running on mobile user terminals and not required for rescue (e.g., games, media players) should be suspended to decrease hardware resources consumption (CPU, memory, etc.) and switch user's attention entirely to the rescue tasks. + +Figure II.1 shows an emergency management use case. + +![Emergency management use case diagram showing interactions between building actuators, network nodes, mobile terminals, and external emergency services.](043e64d41a3368d138ace3816fd26469_img.jpg) + +The diagram illustrates an emergency management use case, divided into two main sections: a light blue section on the left representing building components and a dark blue section on the right representing external emergency services. + +**Left Section (Building Components):** + +- In-building actuators:** Includes icons for Door openers, Emergency lighting, and Sprinklers. +- Motes:** A central network of yellow nodes connected by lines, representing a mesh network. +- Mobile user terminals:** Includes icons for Phones, PDA or tablet PC, and e-health equipment. +- User categories:** Includes icons for Visitors, Personnel, and Disabled. + +**Right Section (External Services):** + +- Emergency operations centre:** A central hub in the dark blue section. +- Emergency services:** Includes icons for an ambulance, a fire extinguisher, and a radiation symbol. + +**Interactions:** + +- Arrows point from the In-building actuators, Motes, and Mobile user terminals towards the central Motes network. +- A large double-headed arrow connects the central Motes network to the Emergency operations centre. +- A vertical double-headed arrow connects the Emergency operations centre to the Emergency services. + +Emergency management use case diagram showing interactions between building actuators, network nodes, mobile terminals, and external emergency services. + +Y.2222(13)\_Fil.1 + +Figure II.1 – Emergency management use case + +# Bibliography + +- [b-ITU-T F.744] Recommendation ITU-T F.744 (2009), *Service description and requirements for ubiquitous sensor network middleware*. +- [b-ITU-T Q.1706] Recommendation ITU-T Q.1706/Y.2801 (2006), *Mobility management requirements for NGN*. +- [b-ITU-T Y.101] Recommendation ITU-T Y.101 (2000), *Global Information Infrastructure terminology: Terms and definitions*. +- [b-ITU-T Y.2001] Recommendation ITU-T Y.2001 (2004), *General overview of NGN*. +- [b-ITU-T Y.2201] Recommendation ITU-T Y.2201 (2009), *Requirements and capabilities for ITU-T NGN*. +- [b-ITU-T Y.2221] Recommendation ITU-T Y.2221 (2010), *Requirements for support of ubiquitous sensor network (USN) applications and services in the NGN environment*. +- [b-ITU News] ITU News No. 3 (April 2012), *Personal safety in emergencies – Innovative application for mobile phones*. +<> + + + +# SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|--------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Terminals and subjective and objective assessment methods | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/Y/T-REC-Y.2232-200801-I_PDF-E/raw.md b/marked/Y/T-REC-Y.2232-200801-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..f951ba56ea84ee663f671df21c18a7d0177e565a --- /dev/null +++ b/marked/Y/T-REC-Y.2232-200801-I_PDF-E/raw.md @@ -0,0 +1,1507 @@ + + +I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**Y.2232** + +(01/2008) + +SERIES Y: GLOBAL INFORMATION +INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS +AND NEXT-GENERATION NETWORKS + +Next Generation Networks – Service aspects: Service +capabilities and service architecture + +# --- **NGN convergence service model and scenario using web services** + +Recommendation ITU-T Y.2232 + +![ITU logo](84a1d09fb489061482111515543b60dc_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with a red lightning bolt striking it, and the text "ITU" in blue. To the right of the globe, the words "International Telecommunication Union" are written in a smaller, blue, sans-serif font. + +ITU logo + +## ITU-T Y-SERIES RECOMMENDATIONS **GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT- GENERATION NETWORKS** + +## GLOBAL INFORMATION INFRASTRUCTURE + +| | | +|-------------------------------------------|-------------| +| General | Y.100–Y.199 | +| Services, applications and middleware | Y.200–Y.299 | +| Network aspects | Y.300–Y.399 | +| Interfaces and protocols | Y.400–Y.499 | +| Numbering, addressing and naming | Y.500–Y.599 | +| Operation, administration and maintenance | Y.600–Y.699 | +| Security | Y.700–Y.799 | +| Performances | Y.800–Y.899 | + +## INTERNET PROTOCOL ASPECTS + +| | | +|--------------------------------------------------------------------|---------------| +| General | Y.1000–Y.1099 | +| Services and applications | Y.1100–Y.1199 | +| Architecture, access, network capabilities and resource management | Y.1200–Y.1299 | +| Transport | Y.1300–Y.1399 | +| Interworking | Y.1400–Y.1499 | +| Quality of service and network performance | Y.1500–Y.1599 | +| Signalling | Y.1600–Y.1699 | +| Operation, administration and maintenance | Y.1700–Y.1799 | +| Charging | Y.1800–Y.1899 | + +## NEXT GENERATION NETWORKS + +| | | +|-----------------------------------------------------------------------|----------------------| +| Frameworks and functional architecture models | Y.2000–Y.2099 | +| Quality of Service and performance | Y.2100–Y.2199 | +| Service aspects: Service capabilities and service architecture | Y.2200–Y.2249 | +| Service aspects: Interoperability of services and networks in NGN | Y.2250–Y.2299 | +| Numbering, naming and addressing | Y.2300–Y.2399 | +| Network management | Y.2400–Y.2499 | +| Network control architectures and protocols | Y.2500–Y.2599 | +| Security | Y.2700–Y.2799 | +| Generalized mobility | Y.2800–Y.2899 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# **Recommendation ITU-T Y.2232** + +# **NGN convergence service model and scenario using web services** + +## **Summary** + +The 'convergence service' in NGN implies the integration of services in NGN in a unified manner to access each service in order to interwork with each service. Recommendation ITU-T Y.2232 defines the convergence model for NGN based on web services and provides a detailed scenario of each convergence model in the form of web services. + +## **Source** + +Recommendation ITU-T Y.2232 was approved on 25 January 2008 by ITU-T Study Group 13 (2005-2008) under Recommendation ITU-T A.8 procedure. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g. interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +### INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2008 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## CONTENTS + +| | Page | +|-------------------------------------------------------------------------------|-------------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 2 | +| 3.1 Terms defined elsewhere:..... | 2 | +| 3.2 Terms defined in this Recommendation..... | 2 | +| 4 Abbreviations and acronyms ..... | 3 | +| 5 Conventions ..... | 4 | +| 6 Requirements to support convergence services model and scenario..... | 4 | +| 7 Web services deployment model in NGN ..... | 4 | +| 7.1 Characteristics of web services ..... | 4 | +| 7.2 Web services deployment model..... | 5 | +| 7.3 Web services gateway (WSG)..... | 7 | +| 7.4 Web services gateway interaction patterns..... | 9 | +| 8 Web services-based convergence model and convergence service scenarios..... | 14 | +| 8.1 Basic convergence model..... | 14 | +| 8.2 Extended convergence model..... | 15 | +| 8.3 Convergence service scenarios..... | 17 | +| 9 Security considerations..... | 21 | +| 9.1 Threats to web services ..... | 21 | +| 9.2 Security requirements for web services..... | 21 | +| Appendix I – Security considerations for web services..... | 23 | +| I.1 Security technologies for web services-based NGN convergence services ... | 23 | +| Appendix II – Interoperability considerations for web services ..... | 25 | +| II.1 Interoperability at the SOAP layer ..... | 25 | +| II.2 Interoperability at the SOAP message security layer ..... | 26 | +| Appendix III – Information flows for WSG ..... | 29 | +| III.1 Case 1: Information flows for security pattern..... | 29 | +| III.2 Case 2: Information flows for substitution pattern..... | 30 | +| III.3 Case 3: Information flows for composition pattern..... | 31 | +| Bibliography..... | 33 | + +## Introduction + +The NGN service architecture has the three main functional characteristics of (i) agnosticism, (ii) support for legacy capabilities and features, and (iii) support for an open service interface (Recommendation ITU-T Y.2012). Among these, the third characteristic implies that the NGN service platform is required to provide an open service interface, which provides an abstraction of the network capabilities. + +NGN users can create and provide enhanced services, which enables application of NGN capabilities using the "applications" functional group known as the application-to-network interface (ANI) (Recommendation ITU-T Y.2012). ANI provides a channel for interactions and exchanges between applications and NGN elements. ANI offers the capabilities and resources needed for the realization of applications. Also, NGN provides open service environment (Recommendation ITU-T Y.2201) for application developers. + +This Recommendation proposes the NGN convergence models and scenario of (i) interactions among web services-enabled NGN services, and (ii) interaction with web services-enabled NGN services, along with NGN services, which does not have a web services feature. The overall value proposition of this Recommendation lies in extending the space of application developers for the NGN services interface to include members of IT communities and others who are in skills areas other than programming language developers, such as web developers. The various perspectives on the value proposition are as follows: + +- The end user is the consumer of the services. The end user is provided with more services in a timelier manner, and services may be delivered that are more personalized to their unique market segments. +- The application developer is the person programming the application who makes use of web services to deliver application functionality to the end user. The developer benefits from (i) access to NGN capabilities using an intuitive function, (ii) the ability to use a common application framework that supports web services to build and deploy their applications. +- A service provider is an entity that operates the NGN services. The value proposition of web services for the service provider is (i) to offer a wide range of services rapidly and inexpensively, (ii) to differentiate itself by means of offering specialized services and serving strategic niche markets, (iii) to reach customers who are only interested in niche applications, and possibly cross-sell them, and (iv) to build customer loyalty by providing a means to customize services and assistance with this. +- The network operator is the entity that supports the network resources that support the web services. The value proposition for the network operator is the increased use of network resources and hence, increased revenue. + +###### Recommendation ITU-T Y.2232 + +# NGN convergence service model and scenario using web services + +# 1 Scope + +The objective of this Recommendation is to describe the NGN convergence service model and scenario using web services. This Recommendation defines the convergence model for NGN based on web services and provides a detailed scenario of each convergence model in the form of web services. + +The term 'convergence' in NGN has focused mainly on the convergence of media, such as voice, data and video. However, to realize the ultimate convergence of services in NGN, it is necessary to develop detailed requirements to allow for the convergence of services. It is also important to clearly identify the value being added by a convergence service. The 'convergence services' in NGN imply the integration of services in NGN in a unified manner to access each service in order to interwork with each service. + +Implementing the convergence service in current networks may be restricted or impossible due to the capabilities of the installed equipment. Moreover, service provisioning of the convergence service to implement new functionalities is essentially restricted to equipment vendors, as the APIs are typically proprietary [ITU-T Y.2012]. Thus, for the open service interface of NGN, NGN is required to support standard ANI API and a unified manner for accessing the NGN services from the IT side. + +Currently, the capabilities and requirements [b-ITU-T Y.2000-Sup.1] [ITU-T Y.2201] for open services environments have been described. Web services is one of the technologies of open services environments. The use of web services is expanding rapidly as the need for application-to-application communication and interoperability grows. In NGN, web services provide a standard means of communication among different software applications of NGN services to the users. To address these capabilities among these applications in NGN environments, and to allow them to be combined for more complex services, a standard reference convergence model is needed in an NGN environment. + +The scope of this Recommendation is to address a convergence service scenario in NGN using web services. This Recommendation covers: + +- Requirements to support convergence services model and scenario. +- A web services deployment model for NGN. +- NGN convergence services model and its scenarios using web services. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[ITU-T Y.2012] Recommendation ITU-T Y.2012 (2006), *Functional requirements and architecture of the NGN release 1*. + +[ITU-T Y.2013] Recommendation ITU-T Y.2013 (2006), *Converged services framework functional requirements and architecture*. + +- [ITU-T Y.2091] Recommendation ITU-T Y.2091 (2008), *Terms and definitions for Next Generation Networks*. +- [ITU-T Y.2201] Recommendation ITU-T Y.2201 (2007), *NGN release 1 requirements*. +- [ITU-T Y.2701] Recommendation ITU-T Y.2701 (2007), *Security requirements for NGN release 1*. +- [W3C SOAP 0] W3C Recommendation (2007), *SOAP Version 1.2 Part 0: Primer (Second Edition)*. +- [W3C SOAP 1] W3C Recommendation (2007), *SOAP Version 1.2 Part 1: Messaging Framework (Second Edition)*. +- [W3C WSDL 0] W3C Recommendation (2007), *Web Services Description Language (WSDL) Version 2.0 Part 0: Primer*. +- [W3C WSDL 1] W3C Recommendation (2007), *Web Services Description Language (WSDL) Version 2.0 Part 1: Core Language*. + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +- 3.1.1 access** [b-ITU-T X.1142]: Performing an action. +- 3.1.2 access control** [b-ITU-T X.1142]: Controlling access in accordance with a policy. +- 3.1.3 access control information** [b-ITU-T X.812]: Any information used for access control purposes, including contextual information. +- 3.1.4 gateway** [b-ITU-T H.310]: A function that converts transmission formats and/or protocols between different network environments. +- 3.1.5 principal** [b-ITU-T X.811]: An entity whose identity can be authenticated. +- 3.1.6 service** [ITU-T Y.2091]: A set of functions and facilities offered to a user by a provider. +- 3.1.7 service convergence** [ITU-T Y.2013]: The coordination of a set of services such that the end user's view is that of a single service. The component services may have different providers. +- 3.1.8 SOAP** [W3C SOAP 1]: The formal set of conventions governing the format and processing rules of a SOAP message. These conventions include the interactions among SOAP nodes generating and accepting SOAP messages for the purpose of exchanging information along a SOAP message path. +- 3.1.9 SOAP intermediary** [W3C SOAP 1]: A SOAP intermediary is both a SOAP receiver and a SOAP sender and is targetable from within a SOAP message. It processes the SOAP header blocks targeted at it and acts to forward a SOAP message towards an ultimate SOAP receiver. +- 3.1.10 WSDL** [W3C WSDL 1]: Web services description language Version 2.0 (WSDL 2.0) provides a model and an XML format for describing Web services. WSDL 2.0 enables one to separate the description of the abstract functionality offered by a service from concrete details of a service description such as "how" and "where" that functionality is offered. + +## 3.2 Terms defined in this Recommendation + +This Recommendation defines the following terms: + +- 3.2.1 convergence service**: A service resulting from service convergence. + +NOTE – In this Recommendation, service convergence is realized using web services technologies. + +**3.2.2 service composition:** Service composition is the capability of creating a new NGN service from other existing NGN services. + +**3.2.3 service provider:** An entity that provides services. + +**3.2.4 service substitution:** Service substitution is a capability for replacing a service when an original requested service is not available. + +**3.2.5 web services:** Web services is a service provided using web services systems. + +**3.2.6 Web services gateway (WSG):** A gateway which handles the web services message between the WSP and WSR. + +**3.2.7 Web services provider (WSP):** A service provider that exposes a capability for use to create web services. + +**3.2.8 Web services requester (WSR):** Client software that makes use of the services provided by a WSP. + +**3.2.9 Web services registry:** An entity that stores web services information (e.g., WSDL). + +**3.2.10 Web services system:** A web services system is a software system designed to support interoperable machine-to-machine interaction over a network using web services standards. + +NOTE – It has an interface described in a machine-processable format (specifically WSDL). Other systems interact with the web services in a manner prescribed by its description using SOAP-messages, typically conveyed using HTTP with an XML serialization in conjunction with other web-related standards. + +# **4 Abbreviations and acronyms** + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|------|--------------------------------------------| +| ANI | Application-to-Network Interface | +| API | Application Program Interface | +| AS | Application Server | +| ASP | Application Service Provider | +| BP | Basic Profile | +| BSP | Basic Security Profile | +| MEP | Message Exchange Pattern | +| NGN | Next Generation Network | +| NWSP | Non-Web Services Provider | +| NWSR | Non-Web Services Requester | +| PEP | Policy Enforcement Point | +| SIP | Session Initiation Protocol | +| SOAP | Simple Object Access Protocol | +| SSP | Service Support Provider | +| TLS | Transport Layer Security | +| UE | User Equipment | +| WSDL | Web Services Description Language | +| WSG | Web Services Gateway | +| WS-I | Web Services Interoperability Organization | + +| | | +|-----|----------------------------| +| WSP | Web Services Provider | +| WSR | Web Services Requester | +| WSS | Web Services Security | +| XML | eXtensible Markup Language | + +# 5 Conventions + +This Recommendation uses the following assumptions: + +- The convergence service is required to utilize various kinds of NGN capabilities. +- If an NGN does not support web services interfaces for the service, the web services system can take into account adaptation mechanisms in WSG. +- The target services of convergence are not only the NGN service but also non-NGN services. +- Convergence services are required to enable timely service creation. +- SOAP is assumed for the binding mechanism, although other binding mechanisms can be used for web services. + +In this Recommendation, the term "web services" is not used as plural, but as a proper noun developed by W3C. + +# 6 Requirements to support convergence services model and scenario + +This clause describes the requirements to support the convergence services model and scenario using web services. For the convergence service scenario using web services, the following requirements are necessary. + +- NGN is required to provide an open interface for application providers to support web services. +- A unified service discovery mechanism is required to be able to find the service, which is the target service for convergence. +- It is required to support the WSDL for the convergence service. In the WSDL, a set of information that describes the interface to and semantics of a service are described. +- It is required to provide service level interoperability underlying various different networks, operating systems and programming languages. +- It is required to provide general security capability for the service, which is opened to make a convergence service. +- Service discovery and invocation is required to support service provider and consumer policies. + +# 7 Web services deployment model in NGN + +Web services systems enable business entities and applications to intercommunicate openly with each other over a network. Web services systems have program-language-independent properties, use message-driven communication, and are easily bound to different transport protocols. In NGN services, it is possible to make common interfaces for service integration using web services technology. + +## 7.1 Characteristics of web services + +The characteristics of web services for the convergence scenarios in NGN are as follows: + +- Loosely coupled connections between services + +Web services systems communicate by passing XML messages via a service externalization layer. The service abstraction layer facilitates the task of developing services that consumes NGN exposed services. + +- Interoperability across open and proprietary platforms + +Web services systems are of high value to the enterprise as they provide, at their core, interoperability among hardware platforms, operating systems, databases, middleware and applications. These allow large organizations to benefit from a flexible IT architecture built on well-established standards without limiting the flexibility of individual lines of business to implement technologies that provide the business capabilities they need. + +- A new approach to programming and application development + +SOAP is a programming protocol that can be used to expose services and contents, thereby creating a dynamic medium (the web, intranet, extranets, and others) for programmable information exchanges. This translates into faster development cycles and lower costs enabled by component reuse, increased developer collaboration, component sharing, and business agility that allow firms to respond to changes in the business environment without being held back by long implementation and deployment cycles on the IT side. + +- An open and flexible technique to deliver services to users anywhere + +Using web services, a company can provide access to inventory transactions, financial data, insurance claim processing, or any type of information, transaction, or process in a reusable and open fashion. + +## 7.2 Web services deployment model + +The basic web services defines an interaction [W3C SOAP 0] [W3C SOAP 1] between service requesters and service providers as an exchange of messages, as shown in Figure 1. + +![Figure 1: General architecture of web services. The diagram shows a central 'Web services registry' box at the top. Below it are two boxes: 'WSR' (Web Service Requester) on the left and 'WSP' (Web Service Provider) on the right. A line connects 'WSR' and 'WSP' at the bottom, with a point labeled 'O_I' (Invocation) in the middle. A line connects 'WSR' and 'Web services registry' on the left, with a point labeled 'O_F' (Finding) on the line. A line connects 'WSP' and 'Web services registry' on the right, with a point labeled 'O_P' (Publication) on the line. The identifier 'Y.2232(08)_F01' is located at the bottom right of the diagram.](7c6d9bfe9c31ce872722d60b73d20df1_img.jpg) + +``` +graph TD; WSR[WSR] --- OF[O_F] --- WSReg[Web services registry]; WSP[WSP] --- OP[O_P] --- WSReg; WSR --- OI[O_I] --- WSP; +``` + +Y.2232(08)\_F01 + +Figure 1: General architecture of web services. The diagram shows a central 'Web services registry' box at the top. Below it are two boxes: 'WSR' (Web Service Requester) on the left and 'WSP' (Web Service Provider) on the right. A line connects 'WSR' and 'WSP' at the bottom, with a point labeled 'O\_I' (Invocation) in the middle. A line connects 'WSR' and 'Web services registry' on the left, with a point labeled 'O\_F' (Finding) on the line. A line connects 'WSP' and 'Web services registry' on the right, with a point labeled 'O\_P' (Publication) on the line. The identifier 'Y.2232(08)\_F01' is located at the bottom right of the diagram. + +**Figure 1 – General architecture of web services** + +In the WSDL, a service and services descriptions are described [W3C WSDL 0]. A service is enabled by a software module deployed on network-accessible platforms provided by the service provider. The service description contains the details of the interface and implementation of the service including the data types, operations, binding information and network location. The service description is supported by WSP. + +In order for an application to take advantage of web services, three behaviours must take place: the publication of service descriptions, the finding and retrieval of service descriptions, and the binding or invoking of services based on the service description. These behaviours can occur singly or iteratively, with any cardinality between the roles. In detail, these operations are: + +- $O_I$ execution (binding or invoking) of services based on the service description +- $O_F$ finding and retrieval of service descriptions +- $O_P$ publication of service descriptions + +The basic web services architecture models the interactions between three roles (WSP, web services registry and WSR). The entire procedure of web services usage can be divided into publish, find (or discovery) and bind (or interaction) phases. + +In the publish phase of web services, the WSP develops its applications and creates a service description, publishes that service description (WSDL) to one or more web services registry to allow discovery with an $O_P$ operation, as shown in Figure 2, and the web services ready to receive messages from the WSR. + +![Sequence diagram showing the information flow of the O_P operation in web services. It involves three lifelines: WSR, Web services registry, and WSP. The WSP sends an O_P (WSDL) message to the Web services registry, and the Web services registry sends an O_P (ACK) message back to the WSP. The WSR lifeline is present but has no messages.](042733dc5e8e7f5f30b60adba3266cde_img.jpg) + +``` + +sequenceDiagram + participant WSR + participant Registry as Web services registry + participant WSP + WSP->>Registry: O_P (WSDL) + Registry-->>WSP: O_P (ACK) + +``` + +Y.2232(08)\_F02 + +Sequence diagram showing the information flow of the O\_P operation in web services. It involves three lifelines: WSR, Web services registry, and WSP. The WSP sends an O\_P (WSDL) message to the Web services registry, and the Web services registry sends an O\_P (ACK) message back to the WSP. The WSR lifeline is present but has no messages. + +**Figure 2 – Information flow of $O_P$ in web services** + +In the find phase of web services, the WSR finds the service description of interest and uses this service description with the $O_F$ operation. + +The web services registry advertises the web services descriptions published to it by WSPs with the $O_P$ operation to help WSRs search through its registry to find a service description of interest with the $O_F$ operation. + +![Sequence diagram showing the information flow of the O_F operation in web services. It involves three lifelines: WSR, Web services registry, and WSP. The WSR sends an O_F (keyboard) message to the Web services registry, and the Web services registry sends an O_F (WSDL) message back to the WSR. The WSP lifeline is present but has no messages.](08441fa90c5fd11994626f662ac13f19_img.jpg) + +``` + +sequenceDiagram + participant WSR + participant Registry as Web services registry + participant WSP + WSR->>Registry: O_F (keyboard) + Registry-->>WSR: O_F (WSDL) + +``` + +Y.2232(08)\_F03 + +Sequence diagram showing the information flow of the O\_F operation in web services. It involves three lifelines: WSR, Web services registry, and WSP. The WSR sends an O\_F (keyboard) message to the Web services registry, and the Web services registry sends an O\_F (WSDL) message back to the WSR. The WSP lifeline is present but has no messages. + +**Figure 3 – Information flow of $O_F$ in web services** + +In the bind phase of web services, the WSR interacts with the services provided by the WSP with the $O_I$ operation. + +![Sequence diagram showing the information flow of the O_I operation in web services. It involves three lifelines: WSR, Web services registry, and WSP. The WSR sends an O_I (SOAP_REQUEST) message to the WSP, and the WSP sends an O_I (SOAP_RESPONSE) message back to the WSR. The Web services registry lifeline is present but has no messages.](fbfa653853daf5541118a9ddecb92284_img.jpg) + +``` + +sequenceDiagram + participant WSR + participant Registry as Web services registry + participant WSP + WSR->>WSP: O_I (SOAP_REQUEST) + WSP-->>WSR: O_I (SOAP_RESPONSE) + +``` + +Y.2232(08)\_F04 + +Sequence diagram showing the information flow of the O\_I operation in web services. It involves three lifelines: WSR, Web services registry, and WSP. The WSR sends an O\_I (SOAP\_REQUEST) message to the WSP, and the WSP sends an O\_I (SOAP\_RESPONSE) message back to the WSR. The Web services registry lifeline is present but has no messages. + +**Figure 4 – Information flow of $O_I$ in web services** + +![Figure 5: Conceptual diagram of the NGN architecture with an extension of web services. The diagram shows the interaction between WSPs, WSR, Web services registry, and the NGN core layers (Service stratum and Transport stratum) via ANI, UNI, and NNI interfaces.](af7916c89a458fdab6c3f443217388ae_img.jpg) + +The diagram illustrates the NGN architecture with an extension of web services. At the top, a dashed box contains several WSPs (Web Service Providers) such as 'WSP (map web services provider)', 'WSP (photo web services provider)', and 'WSP (search web services provider)'. Each WSP contains multiple WSDL (Web Service Description Language) icons. These WSPs are connected to a central WSR (Web Services Registry) and a Web services registry database. The WSR is connected to the Web services registry via an interface labeled $O_F$ . The Web services registry is connected to the WSR via an interface labeled $O_P$ . The WSR is also connected to the Web services registry via an interface labeled $O_P$ . The WSR is connected to the Web services registry via an interface labeled $O_P$ . The WSR is connected to the Web services registry via an interface labeled $O_P$ . + +The main part of the diagram is enclosed in a dashed box representing the NGN core. It is divided into two main layers: the Service stratum (top, green background) and the Transport stratum (bottom, yellow background). The Service stratum contains 'Application support functions and service support functions', 'Service user profiles', and 'Service control functions'. The Transport stratum contains 'Transport user profiles', 'Network attachment control functions', 'Resource and admission control functions', and 'Transport control functions'. Below the Transport stratum is the 'Transport functions' layer. The entire core is connected to 'Management functions' (purple vertical bar on the left) and 'End-user functions' (white vertical bar on the left) via a 'UNI' (User Network Interface) interface. The core is also connected to 'Other networks' (white vertical bar on the right) via an 'NNI' (Network Network Interface) interface. A red line labeled 'ANI' (Application Network Interface) runs horizontally across the top of the core, connecting the WSR and Web services registry to the Service stratum. + +Legend: + - Control: Dashed line + - Media: Blue hatched line + - Management: Green dotted line + Y.2232(08)\_F05 + +Figure 5: Conceptual diagram of the NGN architecture with an extension of web services. The diagram shows the interaction between WSPs, WSR, Web services registry, and the NGN core layers (Service stratum and Transport stratum) via ANI, UNI, and NNI interfaces. + +**Figure 5 – Conceptual diagram of the NGN architecture with an extension of web services** + +NOTE – Figure 5 assumes that the WSP for NGN is located inside NGN. + +For an NGN architecture extension with web services, as shown in Figure 5, ANI can be used as the interface of WSPs, and registers their interfaces (WSDL) to the web services registry, as shown in Figure 5. The WSR can find the interfaces (WSDL) of an NGN service from the web services registry, and invokes the interface of the ANI with a web services access method such as SOAP. Before the interaction, the interface of an NGN service can be registered in the web services registry to access their open interfaces (WSDL) by web services. In WSDL, the location of service, API name, the parameter and its type, and other information for the service are described. If web services are deployed in NGN, various types of services in NGN could combine the services of non-NGN environments such as maps, photos and searches related to web services in a unified manner, implying that additional value-added services are created for NGN end-users. + +## 7.3 Web services gateway (WSG) + +The WSG is a component that has functionalities of not only enabling web services features for non-web services, but also performs intermediate work between the WSR and WSP. Therefore, the main roles of the WSG are to transform messages in a value-added manner among the WSR, WSP, NWSP and NWSR, and to perform certain functions associated with the messages such as security + +management, QoS control, service composition or other operations in a message path among the WSR, WSP, NWSP and NWSR. This implies that the WSG has WSP capabilities, and that its outgoing messages are equivalent to its incoming messages in an application-defined sense. + +![Figure 6: Conceptual diagram of the web services gateway. The diagram shows a central 'WSG' box. Above it is a 'Web services registry' box. Below it are four boxes: 'WSR' (left), 'WSP' (right), 'NWSR' (bottom-left), and 'NWSP' (bottom-right). Arrows indicate message flows: from WSR to WSG (O_F), from WSG to WSR (O_FG), from WSG to WSP (O_PG), from WSP to WSG (O_PG), from WSG to WSR (O_IG), from WSG to WSP (O_IG), from WSG to NWSR (O_1), from NWSR to WSG (O_NWSR), from WSG to NWSP (O_NWSP), and from NWSP to WSG (O_NWSP). A small identifier 'Y.2232(08)_F06' is at the bottom right.](b9ecbc3baefab13719e000faa6e0c7eb_img.jpg) + +Figure 6: Conceptual diagram of the web services gateway. The diagram shows a central 'WSG' box. Above it is a 'Web services registry' box. Below it are four boxes: 'WSR' (left), 'WSP' (right), 'NWSR' (bottom-left), and 'NWSP' (bottom-right). Arrows indicate message flows: from WSR to WSG (O\_F), from WSG to WSR (O\_FG), from WSG to WSP (O\_PG), from WSP to WSG (O\_PG), from WSG to WSR (O\_IG), from WSG to WSP (O\_IG), from WSG to NWSR (O\_1), from NWSR to WSG (O\_NWSR), from WSG to NWSP (O\_NWSP), and from NWSP to WSG (O\_NWSP). A small identifier 'Y.2232(08)\_F06' is at the bottom right. + +**Figure 6 – Conceptual diagram of the web services gateway** + +The differences between the general architecture of web services in Figure 1 and the WSG in Figure 6 are the relationships of the WSG among WSR, WSP, NWSP and NWSR. The NWSP is another type of service provider that has no web services feature, and the NWSR is a service requester that does not include the features of web services. In terms of web services, the WSG consists of a set of request/response messages between the WSP and WSR, such as $O_{FG}$ , $O_{PG}$ , and $O_{IG}$ . Additionally, the WSG has an adopter capability for NWSP and NWSR as in $O_{NWSP}$ and $O_{NWSR}$ . In detail, these operations are: + +- $O_{FG}$ WSG operation for the finding and retrieval of service descriptions +- $O_{PG}$ WSG operation publication of service descriptions +- $O_{IG}$ WSG operation SOAP execution of services based on the service description +- $O_{NWSP}$ WSG operation for proprietary operation with NWSP +- $O_{NWSR}$ WSG operation for proprietary operation with NWSR + +The extended web services model for WSG is similar to the traditional web services model in clause 7.2, and the phases are divided into the publish, find and bind phases. Figures 7, 8 and 9 show the publish phase, find phase and bind phase, respectively. + +![Figure 7: Information flow of O_PG. The diagram shows two boxes: 'Web services registry' on the left and 'WSG' on the right. Two horizontal arrows represent the message flow: the top arrow points from WSG to Web services registry and is labeled 'O_PG (WSDL)'; the bottom arrow points from Web services registry to WSG and is labeled 'O_PG (ACK)'. A small identifier 'Y.2232(08)_F07' is at the bottom right.](1b5a812c8aa20fd5cba28e97001d32de_img.jpg) + +Figure 7: Information flow of O\_PG. The diagram shows two boxes: 'Web services registry' on the left and 'WSG' on the right. Two horizontal arrows represent the message flow: the top arrow points from WSG to Web services registry and is labeled 'O\_PG (WSDL)'; the bottom arrow points from Web services registry to WSG and is labeled 'O\_PG (ACK)'. A small identifier 'Y.2232(08)\_F07' is at the bottom right. + +**Figure 7 – Information flow of $O_{PG}$** + +In the publish phase for WSG, the WSG sends a service description of WSG in forms of WSDL using $O_{PG}$ . The web services registry then registers the service description into the database. The candidate service description, as published in the web services registry, is the basic adapter for NWSP, as well as the security, QoS control, substitution, or other operations interface in a message path between the WSR and WSP. + +![Sequence diagram showing information flow of O_FG between WSG and Web services registry.](33ed1f9b27c7c21c797aa928b0f06851_img.jpg) + +``` + +sequenceDiagram + participant WSG + participant Registry as Web services registry + WSG->>Registry: O_FG (keyword) + Registry-->>WSG: O_FG (WSDL) + +``` + +Y.2232(08)\_F08 + +Sequence diagram showing information flow of O\_FG between WSG and Web services registry. + +**Figure 8 – Information flow of $O_{FG}$** + +The $O_{FG}$ , which finds the interface of the WSG, is also similar with $O_F$ . Using $O_{FG}$ , the WSG can retrieve the service description in the web services registry. It can fetch the WSDL from the web services registry. + +![Sequence diagram showing information flow of O_IG between WSR, WSG, and WSP.](7efae06af3af43ffe5d4b956a679cf54_img.jpg) + +``` + +sequenceDiagram + participant WSR + participant WSG + participant WSP + WSR->>WSG: O_IG (SOAP_REQUEST) + Note over WSR,WSG: ⋮ + WSG->>WSP: Transform SOAP_REQUEST + WSG->>WSP: O_IG (SOAP_REQUEST) + Note over WSG,WSP: ⋮ + WSP->>WSG: O_IG (SOAP_RESPONSE) + Note over WSG,WSP: ⋮ + WSG->>WSP: Transform SOAP_RESPONSE + WSG->>WSR: O_IG (SOAP_RESPONSE) + Note over WSR,WSG: ⋮ + +``` + +Y.2232(08)\_F09 + +Sequence diagram showing information flow of O\_IG between WSR, WSG, and WSP. + +**Figure 9 – Information flow of $O_{IG}$** + +In the bind phase of web services using the WSG, the WSR interacts with the services provided by the WSP with the $O_{IG}$ operation, and the WSG transforms the request message and response message. In terms of SOAP messaging, the WSR consists of a set of request/response messages between the WSP and WSR. + +## 7.4 Web services gateway interaction patterns + +In the context of web services, the interaction pattern is a sequence of interactions between the WSR and one or more WSP/WSG; this achieves measurable results for the services requestor. The basic interaction pattern in web services is "request and response" as shown in Figure 10-a. If the WSR has parameters to be sent to the WSP, the parameters are serialized into a message for transmission to the WSP. The WSP then processes the message content and responds to the WSR. + +It is also possible that the WSR delivers the message to multiple WSPs, as shown in Figure 10-b. The delivery of the messages can be implemented using multicast distribution technology if the underlying transport layer supports this. An alternative implementation may use repetition of a distribution list of intended recipients. + +![Figure 10: Request and response interaction pattern in web services. (a) shows a single WSR box connected to a single WSP box by a double-headed arrow. (b) shows a single WSR box connected to a stack of three WSP boxes by multiple arrows, indicating multiple possible destinations. The label Y.2232(08)_F10 is at the bottom right.](fa859e4e468bfb2710a94527f2c504af_img.jpg) + +Figure 10: Request and response interaction pattern in web services. (a) shows a single WSR box connected to a single WSP box by a double-headed arrow. (b) shows a single WSR box connected to a stack of three WSP boxes by multiple arrows, indicating multiple possible destinations. The label Y.2232(08)\_F10 is at the bottom right. + +**Figure 10 – Request and response interaction pattern in web services** + +However, in some cases, web services interaction patterns could be complex due to different capabilities between the WSR and WSP. In this case, various types of WSG interaction patterns can be applied. Moreover, by combining and adopting different interaction patterns, it is possible to produce different paths for the same usage case. + +In general, the WSG is located between the WSR and WSP, as shown in Figure 11. By use of the WSG, the WSR is able to interact with the WSP. Also, according to the request path of web services, the WSG can be used several times as shown in Figure 12. + +![Figure 11: Basic WSG interaction pattern. A sequence of three boxes: WSR, WSG, and WSP. Arrows show the flow: (1) WSR to WSG, (2) WSG to WSP, (3) WSP to WSG, and (4) WSG to WSR. The label Y.2232(08)_F11 is at the bottom right.](16152cf1d84aea10848758f51a91ff6a_img.jpg) + +Figure 11: Basic WSG interaction pattern. A sequence of three boxes: WSR, WSG, and WSP. Arrows show the flow: (1) WSR to WSG, (2) WSG to WSP, (3) WSP to WSG, and (4) WSG to WSR. The label Y.2232(08)\_F11 is at the bottom right. + +**Figure 11 – Basic WSG interaction pattern** + +![Figure 12: Combination of WSG interaction pattern. A sequence of boxes: WSR, WSG, an ellipsis, another WSG, and WSP. Arrows show the flow: (1) WSR to WSG, (4) WSG to WSR, (2) WSG to WSP, and (3) WSP to WSG. The label Y.2232(08)_F12 is at the bottom right.](41a438d7e4adc17c3a4005e7c9500091_img.jpg) + +Figure 12: Combination of WSG interaction pattern. A sequence of boxes: WSR, WSG, an ellipsis, another WSG, and WSP. Arrows show the flow: (1) WSR to WSG, (4) WSG to WSR, (2) WSG to WSP, and (3) WSP to WSG. The label Y.2232(08)\_F12 is at the bottom right. + +**Figure 12 – Combination of WSG interaction pattern** + +A WSG forwards a message to the ultimate WSP on behalf of the initial WSR. The initial WSR wishes to enforce the non-repudiation property of the route. Any WSG message service handler that appends a routing message must log the routing header information. Signed routing headers and the message readers must be logged at the message handler which passes the message to the ultimate WSP to provide evidence of non-repudiation. + +According to the functionalities of the WSG, the WSG has two functions. One is enabling web services features for non-web services; the other is performing certain functions associated with the message. The following subclauses are various WSG interaction patterns for the WSG. The following interaction pattern can work singly, and several interaction patterns can be mixed up if necessary. + +### 7.4.1 Adapter pattern + +The adoption of non-web services into web services is one of main roles of the WSG. This assumes that the WSG has the capabilities for translation using a proprietary format for NGN services and interworking with the heterogeneous protocol of NGN services. The information flows for WSG with NWSP, as shown in Figure 13, are similar to the conventional WSG shown in Figure 8. However, all NGN services that cannot support web services features cannot be used by the WSG. Thus, before using the WSG for non-web services, an adaptor for non-web services must be procured from the service provider. + +![Figure 13: WSG adapter pattern diagram. It shows three components in boxes: WSR on the left, WSG (adapter) in the middle, and NWSP on the right. There are four numbered arrows: (1) from WSR to WSG, (2) from WSG to NWSP, (3) from NWSP to WSG, and (4) from WSG to WSR. Below the NWSP box is the text 'Y.2232(08)_F13'.](8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg) + +Figure 13: WSG adapter pattern diagram. It shows three components in boxes: WSR on the left, WSG (adapter) in the middle, and NWSP on the right. There are four numbered arrows: (1) from WSR to WSG, (2) from WSG to NWSP, (3) from NWSP to WSG, and (4) from WSG to WSR. Below the NWSP box is the text 'Y.2232(08)\_F13'. + +**Figure 13 – WSG adapter pattern** + +### 7.4.2 Proxy pattern + +The WSG acts as a proxy from non-web NGN services requests to web services. The WSG has the capability of translating using a proprietary format from the NGN service protocol (e.g., SIP, HTTP) to a web protocol. In terms of the interfaces, as (third-party) web services are much broader and change more dynamically compared to the (operator) NGN services, the proprietary interface between the non-web NGN service and the WSG may be limited in terms of network service exposure (when NGN is NWSP) and in terms of using new third-party web services (when NGN is NWSR). + +![Figure 14: WSG proxy pattern diagram. It shows three components in boxes: NWSR on the left, WSG (proxy) in the middle, and WSP on the right. There are four numbered arrows: (1) from NWSR to WSG, (2) from WSG to WSP, (3) from WSP to WSG, and (4) from WSG to NWSR. Below the WSP box is the text 'Y.2232(08)_F14'.](df82d77a0d2637cbf2da9ea920a554fa_img.jpg) + +Figure 14: WSG proxy pattern diagram. It shows three components in boxes: NWSR on the left, WSG (proxy) in the middle, and WSP on the right. There are four numbered arrows: (1) from NWSR to WSG, (2) from WSG to WSP, (3) from WSP to WSG, and (4) from WSG to NWSR. Below the WSP box is the text 'Y.2232(08)\_F14'. + +**Figure 14 – WSG proxy pattern** + +In order to use or expose non-web NGN services through the WSG, as the proprietary interfaces are dependent on the NGN service provider, the NGN service provider and web services provider may need to be contacted beforehand. + +### 7.4.3 Security pattern + +The security pattern enables the WSG to do the security protection (e.g., authentication, authorization and decryption) for the network. When a web services is deployed in the network, it needs to be registered to the network on a WSG. The WSG and the web services can authenticate each other during the registration process. Transport layer security can be used to secure the data. + +The WSG also provides the security protection of the service layer, and it can protect the web services by each web service's own security mechanism or in a single sign on manner. The WSR is authenticated by the WSG, or it can be authenticated by both the WSG and WSP and makes a synthesized authentication result. + +A more detailed description of security patterns can be found in Appendix III. + +![Figure 15: WSG security pattern diagram. It shows three components in boxes: WSR on the left, WSG (security) in the middle, and WSP on the right. There are four numbered arrows: (1) from WSR to WSG, (2) from WSG to WSP, (3) from WSP to WSG, and (4) from WSG to WSR. Below the WSP box is the text 'Y.2232(08)_F15'.](b0d4609bc46c2d88a8318706bb5321f7_img.jpg) + +Figure 15: WSG security pattern diagram. It shows three components in boxes: WSR on the left, WSG (security) in the middle, and WSP on the right. There are four numbered arrows: (1) from WSR to WSG, (2) from WSG to WSP, (3) from WSP to WSG, and (4) from WSG to WSR. Below the WSP box is the text 'Y.2232(08)\_F15'. + +**Figure 15 – WSG security pattern** + +### 7.4.4 QoS control pattern + +The QoS control pattern enables the WSG to control the QoS for the web services. The WSG provides the capability to monitor the QoS of the WSPs, which provide the similar service, and chooses the most suitable WSP to provide the service. When the WSG receives a service request from a WSR, it processes the request according to the WSR's QoS requirement and the WSP's resource status which it monitors or gets it from other WSGs and return the process result to the + +WSR. The request information includes service type information, the QoS requirement parameter information, etc. + +![Sequence diagram showing WSR, WSG (QoS control), and WSP interaction. WSR sends (1) to WSG, WSG sends (2) to WSP, WSP sends (3) to WSG, and WSG sends (4) to WSR.](ff7ce44f3fdd51bae7b231f34df07c6a_img.jpg) + +``` + +sequenceDiagram + participant WSR + participant WSG as WSG (QoS control) + participant WSP + WSR->>WSG: (1) + WSG->>WSP: (2) + WSP-->>WSG: (3) + WSG-->>WSR: (4) + +``` + +Y.2232(08)\_F16 + +Sequence diagram showing WSR, WSG (QoS control), and WSP interaction. WSR sends (1) to WSG, WSG sends (2) to WSP, WSP sends (3) to WSG, and WSG sends (4) to WSR. + +**Figure 16 – WSG QoS control pattern** + +According to the service type information, the WSG queries the WSP's current resource status to get the corresponding WSP's addresses and their current resource status. According to the WSG's control policy, the user's QoS requirement, the obtained WSP's addresses, and their resource status, the WSG may reject the request or generate the addresses list of WSPs and send the result to the WSR. Then the WSR initiates the request to WSP based on the result and gets the response from the WSP. + +The control policy of the WSG may include shortest response time, choosing lowest application payload, or the minimum QoS difference between the selected WSP and the required QoS parameter, or choosing WSPs randomly if there are several WSPs satisfying the user's QoS requirement. The QoS parameters in the QoS requirement may include load rate, bandwidth, response time and/or decode rate, etc. + +### 7.4.5 Screening pattern + +The screening pattern enables the WSG to do the screening function. Screening implies that the provider can offer different levels or types of service functions or service contents to a requester according to rules, such as those that specify special functions that can be forbidden to some users or at some time, or only some functions can be used, or content-forbidden policy. Cooperating with a WSP, a WSG processes the function or content screening of the request. + +![Sequence diagram showing WSR, WSG (screening), and WSP interaction. WSR sends (1) to WSG, WSG sends (2) to WSP, WSP sends (3) to WSG, and WSG sends (4) to WSR.](77464a47f104d0d647b2414591137b64_img.jpg) + +``` + +sequenceDiagram + participant WSR + participant WSG as WSG (screening) + participant WSP + WSR->>WSG: (1) + WSG->>WSP: (2) + WSP-->>WSG: (3) + WSG-->>WSR: (4) + +``` + +Y.2232(08)\_F17 + +Sequence diagram showing WSR, WSG (screening), and WSP interaction. WSR sends (1) to WSG, WSG sends (2) to WSP, WSP sends (3) to WSG, and WSG sends (4) to WSR. + +**Figure 17 – WSG screening pattern** + +The WSR initiates the request which includes at least one type of the following information: the service information, the service functions information or the input parameters information. The service functions in this request can be screened before the service result is formed. The request is directly sent to the WSG (the WSR-originated function screening) or firstly sent to the WSP and then is forwarded to the WSG (the WSP-originated function screening). According to the pre-defined screening information, the WSG screens off the invalid service function of the request and forms a new service request. Then the WSP processes this new request and forms the result. Finally, the result of the request is sent to the WSR. + +In the situation of content screening, the WSR (the WSR-originated content screening)/WSP (the WSP-originated content screening) sends the contents to the WSG to make them screened: it sends a screening request message which specifies the contents to be screened to the WSG, and the message can include the contents as a direct attachment or a URL pointing to the contents on a remote storage entity. The WSG then screens the contents according to the screening rules, which are defined by the WSP or WSR or another third party, such as virus scanning, content categorizing, content filtering or other screening operations. The WSG returns the screening results to the WSR. + +or the WSP. If the screening results are returned to the WSP, the WSP sends the screened contents to the WSR. + +### 7.4.6 Substitution pattern + +The substitution pattern enables the WSG to replace the requested service with another service when the requested service does not work. A more detailed description of the substitution pattern can be found in Appendix III. + +![Sequence diagram for WSG substitution pattern showing WSR, WSG (substitution), WSP1, and WSP2 with numbered messages (1) through (6).](8fa679f79a1bb1f527cba9f29e784e89_img.jpg) + +``` +sequenceDiagram + participant WSR + participant WSG as WSG (substitution) + participant WSP1 + participant WSP2 + + WSR->>WSG: (1) + WSG-->>WSR: (6) + WSG->>WSP1: (2) + WSP1-->>WSG: (3) + WSG->>WSP2: (4) + WSP2-->>WSG: (5) +``` + +Y.2232(08)\_F18 + +Sequence diagram for WSG substitution pattern showing WSR, WSG (substitution), WSP1, and WSP2 with numbered messages (1) through (6). + +**Figure 18 – WSG substitution pattern** + +Service substitution is used after the service is requested. The WSR invokes a web services through a WSG but the service which is provided by one WSP does not work and the WSG does not receive any response until the deadline. The WSG discovers a web services to replace the original one and invokes the new web services. The WSG is required to provide the capability to obtain the service template information based on the service information (e.g., service name). The service template is an abstract service which maps to more than one exact service component and the service template can be obtained through the mapping relationship. Service template information may include service type, operation (function provided by service), parameter (related to every operation, including input parameter and output parameter), etc. The WSG can select another web services which provides the same function to replace the original based on the service template information, and invoke the selected one. + +### 7.4.7 Composition pattern + +The composition pattern enables the WSG to provide a type of service-providing mechanism in which multiple services are invoked in a particular order under the control of service logic which describes the order of the invoking of services and the related parameters. The detailed flow refers to clause III.3. + +![Sequence diagram for WSG composition pattern showing WSR, WSG (composition), WSP1, and WSP2 with numbered messages (1) through (6).](40f30e4d577a17052f8b1e6dc802a0d8_img.jpg) + +``` +sequenceDiagram + participant WSR + participant WSG as WSG (composition) + participant WSP1 + participant WSP2 + + WSR->>WSG: (1) + WSG-->>WSR: (6) + WSG->>WSP1: (2) + WSP1-->>WSG: (3) + WSG->>WSP2: (4) + WSP2-->>WSG: (5) +``` + +Y.2232(08)\_F19 + +Sequence diagram for WSG composition pattern showing WSR, WSG (composition), WSP1, and WSP2 with numbered messages (1) through (6). + +**Figure 19 – WSG composition pattern** + +There are two different kinds of service composition: static service composition and dynamic service composition. For static service composition, it uses concrete service logic specifying concrete services, interfaces invoking information, data flow (services input/output parameters) and control flow (services invoking order) of these services. The WSG invokes these concrete services according to the data flow and control flow and gets the results of these services. The WSG then produces the final result and returns it to the WSR. For dynamic service composition, it uses + +abstract service logic specifying service classes (different services which provide the same service function belong to the same service class), data flow and control flow of these services. The WSG transfers abstract service logic to concrete service logic first to find the concrete services that can fulfil the requirements to replace the service classes and create invoking information for these services. Then the WSG executes the concrete service logic and gets the results of these concrete services. The WSG then produces the final result and returns it to WSR. + +A more detailed description of composition pattern can be found in Appendix III. + +# 8 Web services-based convergence model and convergence service scenarios + +In this clause, the basic convergence model, extended convergence model, and the convergence service scenario based on each convergence model are described. For the convergence model, this Recommendation assumes that the NGN service can be located inside and outside of the ANI such as WSP (NGN service) and WSP (third party NGN service). + +## 8.1 Basic convergence model + +The basic convergence model indicates the interaction model between the services requester and service provider; this is web services-enabled NGN services. Figure 20 shows the basic convergence model based on web services for Internet and NGN services. The WSP in the Internet and NGN publish their interfaces to the web services registry and the application support functions and service support functions components, respectively. The WSR is able to find the web services it requires through the web services registry, and the application support functions and service support functions are able to create web services. + +![Figure 20: The components and operations for the basic convergence model. The diagram shows the interaction between a Web services registry, WSR (Web services request component), WSP (Internet service), WSP (third party NGN service), and the NGN service stratum (containing Application support functions & service support functions and WSP (NGN service)). Operations are indicated by arrows with labels O_F, O_P, O_I, and O_NGN.](2eb23c2210154279f8013a1594fbcc5a_img.jpg) + +``` + +graph TD + WSR[WSR] -- "O_F" --> Registry[Web services registry] + WSR -- "O_I" --> WSP_Internet[WSP Internet service] + WSR -- "O_I" --> WSP_3rd[WSP third party NGN service] + WSR -- "O_I" --> NGN_Stratum + + WSP_Internet -- "O_P" --> Registry + WSP_3rd -- "O_P" --> Registry + + WSP_3rd -- "O_NGN" --> NGN_Stratum + + subgraph NGN_Stratum [NGN service stratum] + ASF[Application support functions & service support functions] + WSP_NGN[WSP NGN service] + ASF --- WSP_NGN + end + + ANI[ANI] -.-> NGN_Stratum + +``` + +The diagram illustrates the components and operations for the basic convergence model. It shows the following components and their interactions: + +- Web services registry**: A central component that interacts with the WSR, WSP (Internet service), and WSP (third party NGN service). +- WSR (Web services request component)**: Interacts with the Web services registry, WSP (Internet service), and WSP (third party NGN service). +- WSP (Internet service)**: Interacts with the Web services registry and WSR. +- WSP (third party NGN service)**: Interacts with the Web services registry and WSR. +- NGN service stratum**: A container for the NGN service components, including: + - Application support functions & service support functions**: Interacts with the WSP (third party NGN service) and WSP (NGN service). + - WSP (NGN service)**: Interacts with the Application support functions & service support functions. + +Operations are indicated by arrows with labels: + +- $O_F$ : Find operation. +- $O_P$ : Publish operation. +- $O_I$ : Invoke operation. +- $O_{NGN}$ : NGN operation. + +The ANI (Application Network Interface) is shown as a vertical line separating the WSP components from the NGN service stratum. + +Figure 20: The components and operations for the basic convergence model. The diagram shows the interaction between a Web services registry, WSR (Web services request component), WSP (Internet service), WSP (third party NGN service), and the NGN service stratum (containing Application support functions & service support functions and WSP (NGN service)). Operations are indicated by arrows with labels O\_F, O\_P, O\_I, and O\_NGN. + +Y.2232(08)\_F20 + +**Figure 20 – The components and operations for the basic convergence model** + +### Components + +- WSR: Web services request component used for calling the WSP. +- WSP (third party NGN services): The WSP component for third party NGN services. +- WSP (Internet service): WSP component for Internet services. +- Web services registry: Searchable set of service descriptions in which service providers publish their service descriptions. + +• Application support functions & service support functions: Providing numerous NGN services based on NGN capabilities for third party service providers and applications. The WSP in application support functions & service support functions is not the FE for NGN, and it is one of the services of NGN, which provides the web services interface. + +**Key to operations** + +OI Binding operation (OI) between the WSR and third party WSP for NGN services or NGN operation (OI) for discovering, interaction with the WSP in NGN or binding operation (OI) between the WSR and WSP for Internet services. + +ONGN Proprietary operation (ONGN) between third party web services provider and NGN services. + +OP Publishing operation (OP) for the service description of NGN services or publishing operation (OP) for the service description of Internet services. + +OF Finding operation (OF) for WSP. + +**Information flows for basic convergence model** + +NOTE – Figure 21 shows an example of the information flows for the basic convergence model. + +![Figure 21 – Information flows for basic convergence model](723827e0738d2743c3b3423760a5c48e_img.jpg) + +The figure is a sequence diagram with five vertical lifelines representing: WSR, Web services registry, Third party NGN service (WSP), Internet service (WSP), and NGN service (WSP) in ASP and SSP. The interactions are grouped into three phases: Publish, Find, and Bind. + +- Publish phase:** + - Third party NGN service (WSP) sends OP (WSDL) to Web services registry. + - Web services registry sends OP (ACK) back to Third party NGN service (WSP). + - Internet service (WSP) sends OP (WSDL) to Web services registry. + - Web services registry sends OP (ACK) back to Internet service (WSP). +- Find phase:** + - WSR sends OF (keyword) to Web services registry. + - Web services registry sends OF (WSDL) back to WSR. + - WSR sends OF (keyword) to NGN service (WSP) in ASP and SSP. + - NGN service (WSP) in ASP and SSP sends OF (WSDL) back to WSR. +- Bind phase:** + - WSR sends OI (SOAP\_REQUEST) to NGN service (WSP) in ASP and SSP. + - NGN service (WSP) in ASP and SSP sends OI (SOAP\_RESPONSE) back to WSR. + - WSR sends OI (SOAP\_REQUEST) to Internet service (WSP). + - Internet service (WSP) sends OI (SOAP\_RESPONSE) back to WSR. + - WSR sends OI (SOAP\_REQUEST) to Third party NGN service (WSP). + - Third party NGN service (WSP) sends ONGN (REQUEST) to NGN service (WSP) in ASP and SSP. + - NGN service (WSP) in ASP and SSP sends ONGN (RESPONSE) back to Third party NGN service (WSP). + - Third party NGN service (WSP) sends OI (SOAP\_RESPONSE) back to WSR. + +Y.2232(08)\_F21 + +Figure 21 – Information flows for basic convergence model + +**Figure 21 – Information flows for basic convergence model** + +**8.2 Extended convergence model** + +The extended convergence model is another interaction model between the WSP and NWSP. In essence, all of the interaction based on web services is covered by the basic convergence model. However, although a service in NGN is not web services, the services can be considered in the convergence model. For the extended convergence model, the WSG is required to adopt the NWSP. + +Figure 22 shows the extended convergence model that uses the NWSP and NWSR in NGN through the WSG. The WSG is able to support more advanced features such as service screening and service compositions. Therefore, this model can provide the advanced convergence model with services in NGN/Internet depending on the capability of the WSG. + +**Rec. ITU-T Y.2232 (01/2008)**      15 + +![Figure 22: The components and operations for extended convergence model. The diagram illustrates the interactions between various service components. On the left, 'WSR' connects to 'Web services registry' (via O_F, O_P), 'WSP (Internet service)' (via O_I), 'Web services gateway (WSG)' (via O_IG), and 'WSP (third party NGN service)' (via O_I). The 'Web services registry' also connects to 'WSP (third party NGN service)' (via O_P), 'WSG' (via O_PG), and 'WSP (Internet service)' (via O_P). The 'WSG' connects to 'NWSR' (via O_NWSR) and 'NWSP (third party NGN service)' (via O_IG). To the right of a vertical 'ANI' line is the 'NGN service stratum' containing 'Application support functions & service support functions', which includes 'WSP (NGN service)' and 'NWSP (NGN service)'. Connections cross the ANI line: 'WSP (third party NGN service)' to 'WSP (NGN service)' (via O_NGN), 'NWSP (third party NGN service)' to 'NWSP (NGN service)' (via O_NGN), and 'WSG' to both NGN services (via O_IG, O_NWSP).](e69b9188aa2c14ec6b21c83f711fef65_img.jpg) + +Y.2232(08)\_F22 + +Figure 22: The components and operations for extended convergence model. The diagram illustrates the interactions between various service components. On the left, 'WSR' connects to 'Web services registry' (via O\_F, O\_P), 'WSP (Internet service)' (via O\_I), 'Web services gateway (WSG)' (via O\_IG), and 'WSP (third party NGN service)' (via O\_I). The 'Web services registry' also connects to 'WSP (third party NGN service)' (via O\_P), 'WSG' (via O\_PG), and 'WSP (Internet service)' (via O\_P). The 'WSG' connects to 'NWSR' (via O\_NWSR) and 'NWSP (third party NGN service)' (via O\_IG). To the right of a vertical 'ANI' line is the 'NGN service stratum' containing 'Application support functions & service support functions', which includes 'WSP (NGN service)' and 'NWSP (NGN service)'. Connections cross the ANI line: 'WSP (third party NGN service)' to 'WSP (NGN service)' (via O\_NGN), 'NWSP (third party NGN service)' to 'NWSP (NGN service)' (via O\_NGN), and 'WSG' to both NGN services (via O\_IG, O\_NWSP). + +**Figure 22 – The components and operations for extended convergence model** + +#### Components + +- WSR: Web services request component used for calling the WSP. +- WSP (third party NGN services): NGN services to the called WSR. +- NWSP (third party NGN services): NGN services to the called WSG. +- WSP (Internet service): WSP component for Internet services. +- Web services registry: Searchable set of service descriptions in which service providers publish their service descriptions. +- WSG: Gateway for interoperability between web services and NGN services. +- Application support functions & service support functions: Providing numerous NGN services based on NGN capabilities for third party service providers and applications. The WSP and NWSP in application support functions & service support functions are not the FEs for NGN, and are one of the services of NGN with web services interface, or other propriety interface. +- NWSR: Services request component, which has no web services feature. + +#### Key to operations + +- | | | +|------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| $O_I$ | Bind operation ( $O_I$ ) between the WSR and third party WSP for NGN or bind operation ( $O_I$ ) between the WSR and WSP on NGN or Internet. | +| $O_{NGN}$ | Proprietary operation ( $O_{NGN}$ ) between third party WSP and NGN services. | +| $O_{IG}$ | WSG operation ( $O_{IG}$ ) between the WSR and WSG and the WSG and NGN service. | +| $O_{PG}$ | Publishing and finding operation ( $O_{PG}$ ) for the service description of the WSG and WSP in Internet, respectively. | +| $O_P$ | Publishing operation ( $O_P$ ) for the service description of third party NGN services or publishing operation ( $O_P$ ) for the service description of Internet services. | +| $O_F$ | Finding operation ( $O_F$ ) for the WSR. | +| $O_{NWSP}$ | Interaction operation ( $O_{NWSP}$ ) between the WSG and NWSP in NGN. | +| $O_{NWSR}$ | Interaction operation ( $O_{NWSR}$ ) between the WSG and NWSR in NGN. | + +#### Information flows for extended convergence model + +NOTE – Figure 23 shows an example of the information flows for the extended convergence model. + +![Sequence diagram showing information flows for the extended convergence model between WSR, Web services registry, WSP (third party NGN service), Web services gateway (WSG), NWSP (NGN services) in ASP & SSP, and WSP (NGN services) in ASP & SSP.](d734a6ea1b381280f043fcf70391b6db_img.jpg) + +``` + +sequenceDiagram + participant WSR + participant Registry as Web services registry + participant WSP3P as WSP (third party NGN service) + participant WSG as Web services gateway (WSG) + participant NWSP as NWSP (NGN services) in ASP & SSP + participant WSPNGN as WSP (NGN services) in ASP & SSP + participant WSPIS as WSP (Internet service) + + Note over Registry: Publish + Registry->>WSP3P: Op (WSDL) + WSP3P->>Registry: Op (ACK) + Registry->>WSG: OpG (WSDL) + WSG->>Registry: OpG (ACK) + Registry->>WSR: OF (keyword) + WSR->>Registry: OF (WSDL) + Note over Registry: Find + Registry->>WSG: OIG (keyword) + WSG->>Registry: OIG (WSDL) + Registry->>WSR: OF (keyword) + WSR->>Registry: OF (WSDL) + Registry->>WSP3P: OI (SOAP_REQUEST) + WSP3P->>WSG: ONGN (REQUEST) + WSG->>WSPNGN: ONGN (REQUEST) + WSPNGN->>WSG: ONGN (RESPONSE) + WSG->>WSP3P: ONGN (RESPONSE) + WSP3P->>Registry: OI (SOAP_RESPONSE) + Registry->>WSR: OI (SOAP_RESPONSE) + Note over Registry: Bind + Registry->>WSG: OIG (SOAP_REQUEST) + WSG->>NWSP: ONWSP (REQUEST) + NWSP->>WSG: ONWSP (RESPONSE) + WSG->>Registry: OIG (SOAP_RESPONSE) + Registry->>WSR: OI (SOAP_RESPONSE) + Registry->>WSP3P: OI (SOAP_REQUEST) + WSP3P->>WSPIS: OI (SOAP_REQUEST) + WSPIS->>WSP3P: OI (SOAP_RESPONSE) + WSP3P->>Registry: OI (SOAP_RESPONSE) + Registry->>WSR: OI (SOAP_RESPONSE) + +``` + +Y.2232(08)\_F23 + +Sequence diagram showing information flows for the extended convergence model between WSR, Web services registry, WSP (third party NGN service), Web services gateway (WSG), NWSP (NGN services) in ASP & SSP, and WSP (NGN services) in ASP & SSP. + +Figure 23 – Introduction flows for extended convergence model + +## 8.3 Convergence service scenarios + +### 8.3.1 Web-based call disposition scenario + +The web-based call disposition service provides web pages for a called party to select response menu items such as answer, reject or forwarding to voice mail when a call arrives to the called party in parallel to normal incoming call ringing. + +The call disposition menu is provided based on web services, by which a personalized user interface and customized call response menu is possible. + +For this service, it is assumed that: + +- The terminal equipment of the user is able to support both SIP communications and web services functions. +- The application server providing NGN communication services is able to access web services directly when the AS has web services interfaces, or through the WSG when the AS does not have web services interfaces. + +#### 8.3.1.1 Scenario description + +The web call disposition service is a web services and it provides a personalized menu to the subscriber. The NGN terminating call application service in the service stratum routes the call based on the response selection of the called party. The web services-enabled NGN AS (WSR) queries the web services registry and requests the web call disposition service based on the returned WSDL. The non-web NGN AS (NWSR) requests the WSG to translate the request and response from the web call disposition services. + +![Figure 24 – Web call disposition service architecture diagram.](366a77fdefb0097b3289b4a011911390_img.jpg) + +The diagram illustrates the architecture of the web call disposition service. At the top is the 'Web services registry'. Below it are three main components: 'WSP (call disposition service)', 'WSR' (Web services-enabled NGN AS), and 'WSG' (Web services gateway). To the right of these is the 'NGN service stratum', which contains 'NWSR' (non-web NGN AS) and 'NGN UE' (NGN User Equipment). The 'Web services registry' has three outgoing connections: one to 'WSP' labeled $O_P$ , one to 'WSR' labeled $O_F$ , and one to 'WSG' labeled $O_F$ . The 'WSP' has two outgoing connections: one to 'WSR' labeled $O_I$ and one to 'WSG' labeled $O_{IG}$ . The 'WSR' has one outgoing connection to 'WSG' labeled $O_{IG}$ . The 'WSG' has one outgoing connection to 'NWSR' labeled $O_{NWSR}$ . The 'NGN service stratum' is connected to the 'NGN UE' and the 'ANI' (Access Network Interface). The 'ANI' is represented by a vertical line at the bottom of the 'NGN service stratum'. + +Figure 24 – Web call disposition service architecture diagram. + +Figure 24 – Web call disposition service + +#### 8.3.1.2 Use cases for web-based call disposition + +Figures 25 and 26 show possible scenarios for the use cases of the web call disposition service. + +![Sequence diagram for Non-web NGN service requesting web disposition service. The diagram shows interactions between Caller A, Callee B, S-CSC-FE, AS-FE (NWSR), WSG, Web services registry, and WSP (call disposition). Key messages include INVITE, O_NWSR (URL request), O_NWSR (disposition request), O_FG(keyword), O_FG(WSDL), O_IG(URL request), O_IG(disposition request), O_IG(URL response), INVITE (web-URL), O_NWSR (URL result response), Web page request, Web page response, Disposition request, Disposition response, O_NWSR (disposition result response), O_IG(disposition response), 200 OK, ACK, and a Call connection bar. Annotations include 'Page pop-up and request user input for call disposition', 'User input such as call accept, reject, forward, SMS reply, etc.', and 'Personalized disposition menu'. A decision box states: 'Decide routing based on the result. In this case, normal accept.'](7133ccf78043568ca62ecbcd43628a4a_img.jpg) + +``` + +sequenceDiagram + participant CA as Caller A + participant CB as Callee B + participant SCSCFE as S-CSC-FE + participant ASFE as AS-FE (NWSR) + participant WSG + participant WSR as Web services registry + participant WSP as WSP (call disposition) + + CA->>SCSCFE: INVITE + SCSCFE->>ASFE: INVITE + ASFE->>WSG: O_NWSR (URL request) + ASFE->>WSG: O_NWSR (disposition request) + WSG->>WSR: O_FG(keyword) + WSG->>WSR: O_FG(WSDL) + WSG-->>WSP: O_IG(URL request) + WSG-->>WSP: O_IG(disposition request) + WSP-->>WSG: O_IG(URL response) + ASFE-->>SCSCFE: INVITE (web-URL) + ASFE-->>WSG: O_NWSR (URL result response) + SCSCFE->>CB: INVITE (web-URL) + CB->>SCSCFE: 200 OK + SCSCFE->>ASFE: 200 OK + WSG-->>WSP: Web page request + WSP-->>WSG: Web page response + WSG-->>WSP: Disposition request + WSP-->>WSG: Disposition response + ASFE-->>WSG: O_NWSR (disposition result response) + WSG-->>WSP: O_IG(disposition response) + SCSCFE->>CB: 200 OK + CB->>CA: 200 OK + CB->>SCSCFE: ACK + SCSCFE->>ASFE: ACK + SCSCFE->>CA: ACK + Note over CA, CB: Call connection + +``` + +Y.2232(08)\_F25 + +Sequence diagram for Non-web NGN service requesting web disposition service. The diagram shows interactions between Caller A, Callee B, S-CSC-FE, AS-FE (NWSR), WSG, Web services registry, and WSP (call disposition). Key messages include INVITE, O\_NWSR (URL request), O\_NWSR (disposition request), O\_FG(keyword), O\_FG(WSDL), O\_IG(URL request), O\_IG(disposition request), O\_IG(URL response), INVITE (web-URL), O\_NWSR (URL result response), Web page request, Web page response, Disposition request, Disposition response, O\_NWSR (disposition result response), O\_IG(disposition response), 200 OK, ACK, and a Call connection bar. Annotations include 'Page pop-up and request user input for call disposition', 'User input such as call accept, reject, forward, SMS reply, etc.', and 'Personalized disposition menu'. A decision box states: 'Decide routing based on the result. In this case, normal accept.' + +**Figure 25 – Non-web NGN service requesting web disposition service (call disposition web services scenarios)** + +- 1) Caller A originates a call to callee B. The terminating S-CSC-FE delivers SIP INVITE to trigger the NGN communication service on application server FE (AS-FE). +- 2) AS-FE sends a message to the WSG to request the URL for the callee's call disposition WSP and to request a disposition response. +- 3) WSG retrieves WSDL from the web services registry and then sends the URL and disposition request to the WSP. +- 4) WSP returns the URL, and AS-FE then returns that URL in the call-info field of INVITE to callee B. Callee B sends normal response 200 OK, to complete the transaction (normal answer case). +- 5) Using the web URL, callee B's terminal connects to the web server to obtain his personalized web call disposition menu. The web page provides and prompts menus such as call accept, reject or forward to voice mail. + +- 6) Callee B answers via an input response on the menu page. This result is sent to the web call disposition service, WSG and then the AS-FE. +- 7) Based on the input result, AS-FE determines further routing. In this case, it is normal call accept, and the AS-FE connects the call to the called party. + +![Sequence diagram for Web NGN service requesting web disposition service. The diagram shows interactions between Caller A, Callee B, S-CSC-FE, AS-FE (WSR), Web services registry, and WSP (call disposition).](0c08e48c08f96934cd6bc6911f3069dc_img.jpg) + +``` + +sequenceDiagram + participant CA as Caller A + participant CB as Callee B + participant SCSCFE as S-CSC-FE + participant ASFE as AS-FE (WSR) + participant WSR as Web services registry + participant WSP as WSP (call disposition) + + CA->>SCSCFE: INVITE + SCSCFE->>ASFE: INVITE + ASFE->>WSR: O_F(keyword) + WSR-->>ASFE: O_F(WSDL) + ASFE->>WSP: O_I(URL request) + WSP-->>ASFE: O_I(disposition request) + ASFE->>WSP: O_I(URL response) + WSP-->>ASFE: O_I(disposition response) + ASFE->>SCSCFE: INVITE (web-URL) + SCSCFE->>CB: INVITE (web-URL) + Note over CB: Page pop-up and request user input for call disposition + CB->>SCSCFE: 200 OK + SCSCFE->>ASFE: 200 OK + CB->>WSP: Web page request + WSP-->>CB: Web page response + Note over WSP: Personalized disposition menu + CB->>WSP: Disposition request + Note over CB: User input such as call accept, reject, forward, SMS reply, etc. + WSP-->>CB: Disposition response + WSP-->>ASFE: O_I(disposition response) + Note over ASFE: Decide routing based on the result. In this case, normal accept. + ASFE->>SCSCFE: 200 OK + SCSCFE->>CA: 200 OK + CA->>SCSCFE: ACK + SCSCFE->>ASFE: ACK + ASFE->>SCSCFE: ACK + SCSCFE->>CB: ACK + Note over CA, CB: Call connection + +``` + +Sequence diagram for Web NGN service requesting web disposition service. The diagram shows interactions between Caller A, Callee B, S-CSC-FE, AS-FE (WSR), Web services registry, and WSP (call disposition). + +Y.2232(08)\_F26 + +**Figure 26 – Web NGN service requesting web disposition service +(call disposition web services scenarios)** + +- 1) Caller A originates a call to callee B. The terminating S-CSC-FE delivers SIP INVITE to trigger the NGN communication service on application server FE (AS-FE). +- 2) AS-FE queries and retrieves WSDL from the web services registry and then sends the URL and disposition request to the WSP. +- 3) When AS-FE receives the URL, it sends the URL in the call-info field of INVITE to callee B. Callee B sends a normal response 200 OK to complete the transaction. +- 4) Using the web URL, callee B's terminal connects to the WSP to obtain his personalized web call disposition menu. The web page provides and prompts menu items such as call accept, reject or forward to voice mail. +- 5) Callee B answers by input response on the menu page. This result is sent to the WSP and then to the AS-FE. + +- 6) Based on the input result, the AS-FE determines further routing. In this case, it is normal call accept, and the AS-FE connects the call to the called party. + +# **9 Security considerations** + +This Recommendation does not identify additional NGN security requirements beyond those contained in [ITU-T Y.2701]. + +Appendix I provide some technical considerations for web services security. + +## **9.1 Threats to web services** + +This clause provides a brief description of the most common threats associated with the deployment of web services. + +- 1) Message alteration +Message information is altered by inserting, removing or modifying information created by the originator of the information and mistaken by the receiver as being the originator's intention. +- 2) Confidentiality +Information within the message is accessible to unintended and unauthorized participants. +- 3) Falsified messages +Messages are constructed and sent to a receiver who believes them to have originated from a party other than the sender. +- 4) Man in the middle +Man in the middle type of attack occurs when a party poses as the other participant to the real sender and receiver in order to fool both participants. +- 5) Principal spoofing +A message is sent which appears to be from another principal. +- 6) Forged claims +A message is sent in which the security claims are forged with the purpose of gaining access to unauthorized information. +- 7) Replay of message parts +A message is sent which includes portions of another message in an effort to gain access to unauthorized information. +- 8) Replay +A whole message is resent by an attacker. +- 9) Denial of service +This is an attack in which the attacker does a small amount of work and forces the system under attack to do a large amount of work. + +## **9.2 Security requirements for web services** + +Security can be a key inhibitor to the widespread implementation and adoption of web services. There are many security challenges for adopting web services. At the highest level, the objective is to create an environment where message level transactions and business processes can be conducted securely in an end-to-end fashion. The requirements for providing end-to-end security for web services are: + +- Authentication mechanisms: This is needed in order to allow the mutual authentication of service provider and service invoker to verify their identities. This also includes data origin + +authentication, whereby the receiver can be sure that the data came from the sender without modification. + +- Authorization to access resources: Once authenticated, authorization mechanisms control invoker access to appropriate system resources. There is controlled access to systems and their components. +- Data integrity and confidentiality: This is to ensure that information has not been modified during transmission and is only accessible to intended parties. Encryption technology and digital signature techniques can be used for this purpose. +- Integrity of transactions and communications: This is needed to ensure that the business process was done properly and the flow of operations was executed in a correct manner. +- Non-repudiation: A party to a transaction cannot deny the occurrence of the transaction. +- End-to-end integrity and confidentiality of messages: The integrity and confidentiality of messages must be ensured even in the presence of intermediaries. +- Provide security and audit trails: This is needed in order to trace user access, behaviour and system integrity verification. +- Distributed enforcement of security policy: Implementers must be able to define a security policy [b-IETF 2828] and enforce it across various platforms with varying privileges. + +# Appendix I + +## Security considerations for web services + +(This appendix does not form an integral part of this Recommendation) + +Web services can be protected using security techniques that are designed to reduce risks associated with security threats. The choice of security mechanism in many cases is dependent on the application and the related threats to that application. Security can be implemented at the WSG level. The WSG can serve as a policy enforcement point (PEP) to enforce message level security. + +### I.1 Security technologies for web services-based NGN convergence services + +This clause provides a summary of security technologies that can be used with web services. + +#### I.1.1 Transport layer security + +This clause takes a look at using the transport layer to secure SOAP messages that are sent from a sender to a receiver. This approach is limited when there are intermediaries in the message path, since termination of transport layer security at an endpoint may allow that intermediary to modify or examine messages. For HTTP-based bindings of SOAP, TLS [b-IETF 4346] provides point-to-point security (see Figure I.1). However, for web services there is a need for end-to-end security in which multiple intermediaries can exist between the original service requester and the service provider. Transport layer TLS does not support XML-based element signing or encryption such as signing or encrypting part of a large XML document. Transport layer security mechanisms may be used to secure messages between two adjacent SOAP nodes whereas message layer security mechanisms can be used in the presence of intermediaries or when data origin authentication is required. + +![Diagram illustrating Transport and message level security. It shows a sequence of nodes: Sender, SOAP intermediary, SOAP intermediary, and Receiver. Solid arrows labeled 'SOAP message' connect the Sender to the first intermediary, and the second intermediary to the Receiver. A dashed arrow labeled 'SOAP message' connects the first intermediary to the second intermediary. Two brackets above the diagram, each labeled 'Transport layer security context', span the connections between the Sender and the first intermediary, and between the second intermediary and the Receiver. A long bracket below the entire sequence is labeled 'SOAP message layer security context: end-to-end'. The identifier 'Y.2232(08)_FI.1' is located at the bottom right of the diagram area.](f2ea0f64a770b22b902820457d262265_img.jpg) + +Y.2232(08)\_FI.1 + +Diagram illustrating Transport and message level security. It shows a sequence of nodes: Sender, SOAP intermediary, SOAP intermediary, and Receiver. Solid arrows labeled 'SOAP message' connect the Sender to the first intermediary, and the second intermediary to the Receiver. A dashed arrow labeled 'SOAP message' connects the first intermediary to the second intermediary. Two brackets above the diagram, each labeled 'Transport layer security context', span the connections between the Sender and the first intermediary, and between the second intermediary and the Receiver. A long bracket below the entire sequence is labeled 'SOAP message layer security context: end-to-end'. The identifier 'Y.2232(08)\_FI.1' is located at the bottom right of the diagram area. + +**Figure I.1 – Transport and message level security** + +#### I.1.2 Message level security + +W3C SOAP specifications do not specify how to deal with message related security issues as such. However, W3C specifications allows for the ability to build extensions to the original SOAP standard. In this regard, the OASIS WS-Security versions specifications (WSS) 1.0 and 1.1 [b-OASIS WSS 1.0] [b-OASIS WSS 1.1] use these extensibility options to provide security functions to SOAP. WSS specifications secure the SOAP foundation layer by leveraging core technologies such as W3C XML Signature, W3C XML Encryption, W3C XML Canonicalization, and TLS. WSS adds security to SOAP messages by specifying how the header part of the message can be used to carry along security information. + +In WSS 1.0 [b-OASIS WSS 1.0], the OASIS specification provides the underlying foundation for SOAP message level security. [b-OASIS WSS 1.0] develops mechanisms for identifying the origin of a message and verifying tampering through the use of signatures. [b-OASIS WSS 1.0] provides mechanisms for message integrity by ensuring that only the intended recipient is able to see the + +message through the use of encryption. [b-OASIS WSS 1.0] introduces a security header to a SOAP message and three key elements: + +- Tokens: SOAP messages can contain security tokens with authentication information such as Username tokens, X.509 tokens, SAML tokens, among others. These tokens can be part of security headers and can vouch for security claims to recipients. +- Signature elements: Security headers can contain signature elements that can sign any part of the message. The recipient can use the signature to verify that the sender's request has not been changed and that the message really originated from the sender. +- Encryption elements: Some parts of the SOAP message can be encrypted to protect sensitive information from unauthorized entities. + +[b-OASIS WSS 1.1] enhances [b-OASIS WSS 1.0] with additional mechanisms to convey token information (e.g., sending a thumbprint of an X.509, or a SHA1 of an encrypted key previously available with cooperation between parties). [b-OASIS WSS 1.1] introduces the concept of *SignatureConfirmation* that enables a communication sender to confirm that the received message was generated in response to a message it initiated in its unaltered form. In this technique, the recipient sends back the signature values received from the sender in the *SignatureConfirmation* element. This technique helps to prevent certain forms of reply and message alteration attacks. + +[b-OASIS WSS 1.1] became an OASIS standard as of February 1, 2006. The series of web services standards consists of the following set of specifications: + +- 1) WS-Security Core Specification 1.1 +- 2) Username Token Profile 1.1 +- 3) X.509 Token Profile 1.1 +- 4) SAML Token profile 1.1 +- 5) Kerberos Token Profile 1.1 +- 6) Rights Expression Language (REL) Token Profile 1.1 +- 7) SOAP with Attachments (SWA) Profile 1.1 + +This Recommendation requires security solutions of convergence services to build [b-OASIS WSS 1.1] onto in order to implement security for SOAP messages. Developers can use [b-OASIS WSS 1.1] specification in conjunction with other web services extensions and higher-level application-specific protocols to accommodate a wide variety of security models and security technologies. + +## Appendix II + +## Interoperability considerations for web services + +(This appendix does not form an integral part of this Recommendation) + +This appendix provides an overview of interoperability technologies for web services. + +### II.1 Interoperability at the SOAP layer + +In order for web services to work in a uniform fashion, interoperability at the SOAP, WSDL, UDDI and SOAP message security levels must be ensured. + +SOAP and WSDL specifications include a number of ambiguities, inconsistencies and potential errors. Ambiguities in these specifications allow adopters to interpret the intention of the standard. As a result, not all developers interpret the standards in the same way. + +Interoperability at the SOAP level is addressed by the WS-I Basic Profile family of specifications. WS-I has developed [b-WS-I BP 1.1] that develops a set of constraints and best practice guidelines that can help developers write interoperable web services. [b-WS-I BP 1.1] provides guidelines for how SOAP; Web Services Description Language; Universal Description, Discovery and Integration 2.0; XML 1.0; and XML Schema [b-W3C XML] should interoperate. + +In this appendix, the term BP means both [b-WS-I BP 1.0] and [b-WS-I BP 1.1]. + +#### II.1.1 BP usage scenarios + +The BP [b-WS-I BP 1.0] [b-WS-I BSP 1.0] discuss three basic message exchange patterns (MEPs). + +- One-way: A SOAP message is sent, either directly or through intermediaries, to a SOAP receiver. No response message is returned. + +![Diagram of the One-way exchange pattern showing a single message flow from Sender to Receiver.](dfa6249d64e9f63db89f2c5b7bbd01de_img.jpg) + +``` +graph LR; Sender[Sender] -- "SOAP//HTTP" --> Receiver[Receiver]; +``` + +Y.2232(08)\_FII.1 + +Diagram of the One-way exchange pattern showing a single message flow from Sender to Receiver. + +**Figure II.1 – One-way exchange pattern** + +- Synchronous request/response: A SOAP message (the request) is sent, either directly or through intermediaries, to an ultimate SOAP receiver. A SOAP message (the response) is sent by the request's ultimate SOAP receiver through the reverse path followed by the request to the request's initial SOAP sender. + +![Diagram of the Synchronous request/response exchange pattern showing a request message from Sender to Receiver and a response message from Receiver to Sender.](8dd83c9e4e123aaaf3d521db1c4c416d_img.jpg) + +``` +graph LR; Sender[Sender] -- "SOAP//HTTP" --> Receiver[Receiver]; Receiver -- "SOAP//HTTP" --> Sender; +``` + +Y.2232(08)\_FII.2 + +Diagram of the Synchronous request/response exchange pattern showing a request message from Sender to Receiver and a response message from Receiver to Sender. + +**Figure II.2 – Synchronous request/response exchange pattern** + +- Basic callback: A SOAP message (the request) is sent, either directly or through intermediaries, to an ultimate SOAP receiver, and an acknowledgement message is returned in the form of a synchronous request/response. The request contains information that indicates an endpoint for the SOAP node where the response should be sent. The request's + +ultimate SOAP receiver sends the response to that SOAP node, which returns an acknowledgement message in the form of synchronous request/response. + +![Sequence diagram showing a basic callback exchange pattern between a Sender and a Receiver. The Sender sends a SOAP//HTTP request: initial, the Receiver responds with SOAP//HTTP response: ACK. The Sender then sends a SOAP//HTTP request: final, and the Receiver responds with SOAP//HTTP response: ACK.](d9843ac5dfc4bbe9e4d21b8898723b5e_img.jpg) + +``` +sequenceDiagram + participant S as Sender + participant R as Receiver + S->>R: SOAP//HTTP request: initial + R-->>S: SOAP//HTTP response: ACK + S->>R: SOAP//HTTP request: final + R-->>S: SOAP//HTTP response: ACK +``` + +Y.2232(08)\_FII.3 + +Sequence diagram showing a basic callback exchange pattern between a Sender and a Receiver. The Sender sends a SOAP//HTTP request: initial, the Receiver responds with SOAP//HTTP response: ACK. The Sender then sends a SOAP//HTTP request: final, and the Receiver responds with SOAP//HTTP response: ACK. + +**Figure II.3 – Basic callback exchange pattern** + +#### II.1.2 BP scope conformance + +Conformance to the BP means adherence to the profile's scope and requirements. Requirements are the rules that web services need to adhere to in order to meet the BP standards for interoperability. The basic type is conformance at the level of an artefact. Artefacts are the primary elements of any web service. In general, the BP has rules about the following types of artefacts: + +- Messages, which are protocol elements that are exchanged to affect a web service. The scope of conformance is the entire message. +- Descriptions, which in the BP implies descriptions of types, messages, interfaces and their protocol and data format bindings, and the network access points associated with web services. The scope of conformance is `wsdl:port`, or parts of a port. +- REGDATA, which are statements (in UDDI for instance) about web services that are used to discover their capabilities. The scope of conformance is `bindingTemplate` or `tModels`. + +### II.2 Interoperability at the SOAP message security layer + +SOAP messages are composed of XML elements. Using WS-Security techniques, these elements may be signed, encrypted, or signed and encrypted. These elements can be referenced from other elements. Each element within a SOAP message may be processed by an intermediary that can add more data and sign and encrypt the incremental data and/or or the combined data. + +WS-Security (WSS) provides a framework for securing SOAP messages. The framework is flexible and is designed to accommodate a wide range of security scenarios. As such, it is difficult for various implementations of WS-Security to interoperate properly. For this reason, WS-I has developed the basic security profile (BSP) to provide clarifications and constraints in order to enhance the interoperability of WS-Security implementations. The BSP extends the profiles created by the WS-I Basic Profile (BP) by adding interoperability guidelines for security. [b-WS-I BSP 1.0] and [b-WS-I BSP 1.1] are available on the WS-I public site. + +The BSP adds security to the same three basic message exchange patterns (MEPs) that were adopted from the scenarios defined for the basic profile. + +#### II.2.1 BSP strength of requirements + +The BSP focuses on improving interoperability by strengthening requirements when possible and constraining flexibility and extensibility when appropriate. The BSP limits the set of common functionality that vendors must implement and thus enhances the chances for interoperability. + +The guiding principles enumerated in the BSP declare that there is no guarantee of interoperability, that the profile should "do no harm" and to make statements that are testable when possible. The profile does not address issues in the profiled standards that do not affect interoperability. The BSP committee worked so that enhancing interoperability does not create new security threats. + +It is not the intent of the profile to define security best practices. However, when multiple options exist, the profile considers known security weaknesses and makes choices that reduce the risks and that act as a means of reducing choice and thus enhancing interoperability. The profile assumes that interoperability of lower-layer protocols and technologies (e.g., encryption and signature algorithms) are adequate and well-understood. The basic security profile restates selected requirements from the WS-Security errata rather than including the entire errata by reference, preferring interoperability over strict conformance. + +The profile includes requirement statements about two kinds of artefacts; SECURE\_ENVELOPE and SECURE\_MESSAGE. A SECURE\_ENVELOPE is a SOAP envelope that has been subjected to integrity and/or confidentiality protection. A SECURE\_MESSAGE expands the scope of the SECURE\_ENVELOPE to include protocol elements transmitted with the SECURE\_ENVELOPE that have been subject to integrity and/or confidentiality protection. + +#### II.2.2 BSP conformance + +In order to conform to the BSP, any artefact that contains a construct that is addressed in the profile must conform to any statements that constrain its use. Conformant receivers are not required to accept all possible conformant messages. Conformance applies to deployed instances of services. Since major portions of the BSP may or may not apply in certain circumstances, individual URIs may be used to indicate conformance to parts of the BSP including the core profile or additional sections of the BSP for Username token, X.509 token, and SOAP attachments. + +The BSP includes statements that are interoperability requirements as well as statements that are security considerations. The normative requirement statements are identified by numbers prefixed with the letter 'R', for example Raaaa where aaaa is the statement number. These statements contain one requirement level keyword (i.e., "MUST") and one conformance target. The following conformance targets are used in the BSP: + +- SECURE\_ENVELOPE: A SOAP envelope that contains sub-elements that have been subject to integrity and/or confidentiality protection. A message is considered conformant when all of its contained artefacts are conformant with all statements in the BSP that are related to them. Use of artefacts for which there are no statements in the basic security profile does not affect conformance. +- SECURE\_MESSAGE: Protocol elements that have WS-Security applied to them. Protocol elements include a primary SOAP envelope and optionally associated SOAP attachments. +- SENDER: Software that generates a message according to the protocol(s) associated with it. A sender is considered conformant when all of the messages it produces are conformant and its behaviour is conformant with all statements related to SENDER in the BSP. +- RECEIVER: Software that consumes a message according to the protocol(s) associated with it. A receiver is considered conformant when it is capable of consuming conformant messages containing the artefacts that it supports and its behaviour is conformant with all statements related to RECEIVER in the BSP. +- INSTANCE: Software that implements a `wsdl:port` or a `uddi:bindingTemplate`. +- SECURITY\_HEADER: An element included as a child of `soap:Envelope/soap:Header` and named `wsse:Security`. +- REFERENCE: A SIGNATURE `ds:Reference` element. +- SIGNATURE: An element included as a child of a SECURITY\_HEADER and named `ds:Signature`. +- ENCRYPTED\_KEY: An element included as a child of a SECURITY\_HEADER and named `xenc:EncryptedKey`. + +- ENCRYPTION\_REFERENCE\_LIST: An element which is included as a child of a SECURITY\_HEADER and named `xenc:ReferenceList`. +- ENCRYPTED\_KEY\_REFERENCE\_LIST: An element which is included as a child of an ENCRYPTED\_KEY and named `xenc:ReferenceList`. +- ENCRYPTED\_DATA: An element named `xenc:EncryptedData` which is referenced by either an ENCRYPTED\_KEY\_REFERENCE\_LIST or an ENCRYPTION\_REFERENCE\_LIST. +- SECURITY\_TOKEN\_REFERENCE: An element included as a descendant of a SECURITY\_HEADER or an ENCRYPTED\_DATA and which is named `wsse:SecurityTokenReference`. +- INTERNAL\_SECURITY\_TOKEN: A security token defined in a security token profile and that is either a child of a SECURITY\_HEADER or a child of a `wsse:Embedded` element in a SECURITY\_TOKEN\_REFERENCE. +- EXTERNAL\_SECURITY\_TOKEN: A security token defined in a security token profile that is external to a SECURE\_ENVELOPE. +- SECURITY\_TOKEN: Either an INTERNAL\_SECURITY\_TOKEN or an EXTERNAL\_SECURITY\_TOKEN (e.g., Username token, X.509 certificate token, REL token, or SAML token). +- TIMESTAMP: An element included as a child of a SECURITY\_HEADER and named `wsu:Timestamp`. +- MIME\_PART: The MIME-defined header fields and contents of one of the parts in the body of a multipart entity in a SECURE\_MESSAGE. + +In BSP, certain statements are considered clarifying statements. The intent of these statements is to eliminate confusion about the intended interpretation of a requirement from an underlying specification. Clarifying statements are identified by adding a suffix of a lower case letter 'c', i.e., Rxxxxc, where xxxx is the requirement number. Additional clarifying statements are also identified by numbers prefixed by the letter 'C', i.e., Cyyyy, where yyyy is the statement number. These statements are non-normative and are used to provide clarification in order to eliminate confusion. + +# Appendix III + +## Information flows for WSG + +(This appendix does not form an integral part of this Recommendation) + +This appendix provides information flows for the WSG from clause 7.4 in detail. + +### III.1 Case 1: Information flows for security pattern + +There are two models for security management about the web services gateway: redirect model and proxy model. + +When the WSR initiates a request without the security information to a WSP, this request which includes the address of the WSP can be directly sent to the WSP or first sent to the WSG and then be forwarded to a WSP. The WSP then instructs the WSR to be authenticated by the WSG and/or instructs the WSG to prepare to the security mechanism to the request. + +![Sequence diagram showing information flow between WSR, WSG, and WSP for the redirect model.](875c6f4f441fdd3ca7e1908fd1582983_img.jpg) + +``` +sequenceDiagram + participant WSR + participant WSG + participant WSP + + WSR->>WSP: OI(SOAP_REQUEST) + WSP-->>WSG: OI(SOAP_RESPONSE) + WSG-->>WSR: OIG(SOAP_REQUEST) + WSG-->>WSR: OIG(SOAP_RESPONSE) + WSR->>WSP: OI(SOAP_REQUEST) + WSP-->>WSR: OI(SOAP_RESPONSE) +``` + +The diagram illustrates the information flow in the redirect model for security pattern. It involves three entities: WSR (Web Services Requester), WSG (Web Services Gateway), and WSP (Web Services Provider). The flow is as follows: 1. WSR sends OI(SOAP\_REQUEST) to WSP. 2. WSP sends OI(SOAP\_RESPONSE) to WSG. 3. WSG sends OIG(SOAP\_REQUEST) to WSR. 4. WSG sends OIG(SOAP\_RESPONSE) to WSR. 5. WSR sends OI(SOAP\_REQUEST) to WSP. 6. WSP sends OI(SOAP\_RESPONSE) to WSR. The diagram is labeled Y.2232(08)\_FIII.1. + +Sequence diagram showing information flow between WSR, WSG, and WSP for the redirect model. + +**Figure III.1 – Information flow of redirect model for security pattern** + +In a redirect model, the WSR can send the authentication information to the WSG and can request the WSG to do the authentication. The WSG can authenticate the WSR according to the WSP's own security mechanism or in a single sign on manner. The authentication result is returned to the WSR, then the WSR sends the request carrying the authentication result to the WSP, and this request may be encrypted by the WSR according to the WSP's security mechanism. If the request is encrypted, the WSP can first decrypt the request. The WSP applies the security process to the request, that is checks the authentication result based on its own security mechanism and forms the final authorization result. Then, the WSP can process the request and returns a response to the WSR, and this response may also be encrypted by the WSP. + +![Sequence diagram showing information flow of proxy model for security pattern between WSR, WSG, and WSP.](e451401f8fa77b466f401d5fce15b26c_img.jpg) + +``` + +sequenceDiagram + participant WSR + participant WSG + participant WSP + + WSR->>WSP: OI(SOAP_REQUEST) + WSP->>WSR: OI(SOAP_RESPONSE) + WSR->>WSG: OIG(SOAP_REQUEST) + WSG->>WSP: OIG(SOAP_REQUEST) + WSP->>WSG: OIG(SOAP_RESPONSE) + WSG->>WSR: OIG(SOAP_RESPONSE) + +``` + +Y.2232(08)\_FIII.2 + +Sequence diagram showing information flow of proxy model for security pattern between WSR, WSG, and WSP. + +**Figure III.2 – Information flow of proxy model for security pattern** + +In a proxy model, the WSR initiates a request carrying the authentication information and sends it to the WSG. This request may also be encrypted by the WSR according to the WSP's security mechanism or the WSG's security mechanism. If the request is encrypted, the WSG can firstly decrypt the request. The WSG authenticates the request according to the WSP's own security mechanism or in a single sign on manner and then the request is forwarded to the WSP through the transport layer secure link. The WSP processes the request and returns a response, and this response is first sent to the WSG. The WSG may apply some security process to the response, such as encrypting the response, and then forwards the response to the WSR. + +### III.2 Case 2: Information flows for substitution pattern + +The information flow for the substitution pattern is as follows: + +![Sequence diagram showing information flow of substitution pattern between WSR, WSG, WSP1, and WSP2.](fcbc3c31776721edc98ceb1944ec438f_img.jpg) + +``` + +sequenceDiagram + participant WSR + participant WSG + participant WSP1 + participant WSP2 + + WSR->>WSG: OIG(SOAP_REQUEST) + WSG->>WSP1: OIG(SOAP_REQUEST) + WSP1--xWSG: No response + WSG->>WSP2: OIG(SOAP_REQUEST) + WSP2->>WSG: OIG(SOAP_RESPONSE) + WSG->>WSR: OIG(SOAP_RESPONSE) + +``` + +Bind { + +Y.2232(08)\_FIII.3 + +Sequence diagram showing information flow of substitution pattern between WSR, WSG, WSP1, and WSP2. + +**Figure III.3 – Information flow of substitution pattern** + +The WSR sends a service request via OIG to the WSG and the WSG relays the service request to the WSP1. The WSG does not receive any response or receives a failure response, then the WSG obtains the service template, which maps to more than one service providing the same service function, based on the original WSP1's service information. Based on the obtained service template, the WSG gets another service provided by WSP2 with the same service function. The WSG then uses the new service of WSP2 to replace the original service of WSP1. The WSG sends the service request to WSP2, the WSP then processes the service request and produces the service response. Finally, WSP2 sends the service response to the WSG and the WSG relays this response back to the WSR. + +### III.3 Case 3: Information flows for composition pattern + +There are two models for services composition about the web services gateway: static service composition and dynamic service composition. + +In both static service composition and dynamic service composition, the WSG publishes the service description of composition services into the web services registry via an OPG operation. Then the WSR can find the service description via an OF operation and get the composition services information according to the service descriptions. + +The Information flow of concrete service logic of composition pattern is as follows: + +![Sequence diagram showing the information flow of static service composition pattern. The diagram involves four participants: Web services requester, NGN service 1 (web services provider), WSG (composition), and NGN service 2 (web services provider). The flow is as follows: 1. Web services requester sends O_IG(SOAP_REQUEST) to WSG. 2. WSG sends O_IG(SOAP_REQUEST) to NGN service 1. 3. NGN service 1 sends O_IG(SOAP_RESPONSE) back to WSG. 4. WSG sends O_IG(SOAP_REQUEST) to NGN service 2. 5. NGN service 2 sends O_IG(SOAP_RESPONSE) back to WSG. 6. WSG sends O_IG(SOAP_RESPONSE) back to Web services requester.](b2f5606b9c7184c1c6070a290080a3e3_img.jpg) + +``` + +sequenceDiagram + participant WSR as Web services requester + participant NS1 as NGN service 1 +(web services provider) + participant WSG as WSG +(composition) + participant NS2 as NGN service 2 +(web services provider) + + WSR->>WSG: OIG(SOAP_REQUEST) + WSG->>NS1: OIG(SOAP_REQUEST) + NS1-->>WSG: OIG(SOAP_RESPONSE) + WSG->>NS2: OIG(SOAP_REQUEST) + NS2-->>WSG: OIG(SOAP_RESPONSE) + WSG-->>WSR: OIG(SOAP_RESPONSE) + +``` + +Y.2232(08)\_FIII.4 + +Sequence diagram showing the information flow of static service composition pattern. The diagram involves four participants: Web services requester, NGN service 1 (web services provider), WSG (composition), and NGN service 2 (web services provider). The flow is as follows: 1. Web services requester sends O\_IG(SOAP\_REQUEST) to WSG. 2. WSG sends O\_IG(SOAP\_REQUEST) to NGN service 1. 3. NGN service 1 sends O\_IG(SOAP\_RESPONSE) back to WSG. 4. WSG sends O\_IG(SOAP\_REQUEST) to NGN service 2. 5. NGN service 2 sends O\_IG(SOAP\_RESPONSE) back to WSG. 6. WSG sends O\_IG(SOAP\_RESPONSE) back to Web services requester. + +**Figure III.4 – Information flow of static service composition pattern** + +For static service composition, the WSG executes the concrete service logic to invoke the corresponding services and gets the results from them. Finally, the WSG produces the execution result of the composition services and returns it to the WSR. + +The information flow of dynamic service composition pattern is as follows: + +![Sequence diagram showing the information flow of dynamic service composition pattern between WSR, Web services registry, WSP1, WSG, and WSP2.](7f5df81190b8dc50dad2604562ae0715_img.jpg) + +``` + +sequenceDiagram + participant WSR + participant Registry as Web services registry + participant WSP1 + participant WSG + participant WSP2 + + WSR->>WSG: OIG(SOAP_REQUEST) + WSG->>Registry: OFG(keyword) + Registry->>WSG: OFG(WSDL) + WSG->>WSP1: OIG(SOAP_REQUEST) + WSP1->>WSG: OIG(SOAP_RESPONSE) + WSG->>WSP2: OIG(SOAP_REQUEST) + WSP2->>WSG: OIG(SOAP_RESPONSE) + WSG->>WSR: OIG(SOAP_RESPONSE) + +``` + +The diagram illustrates the information flow in a dynamic service composition pattern. It involves five entities: WSR (Web Service Requester), Web services registry, WSP1 (Web Service Provider 1), WSG (Web Service Gateway), and WSP2 (Web Service Provider 2). The flow is as follows: + +- WSR sends an $O_{IG}(\text{SOAP\_REQUEST})$ to the WSG. +- The WSG sends $O_{FG}(\text{keyword})$ to the Web services registry and receives $O_{FG}(\text{WSDL})$ back. +- WSG sends $O_{IG}(\text{SOAP\_REQUEST})$ to WSP1 and receives $O_{IG}(\text{SOAP\_RESPONSE})$ back. +- WSG sends $O_{IG}(\text{SOAP\_REQUEST})$ to WSP2 and receives $O_{IG}(\text{SOAP\_RESPONSE})$ back. +- WSG sends the final $O_{IG}(\text{SOAP\_RESPONSE})$ back to WSR. + +Sequence diagram showing the information flow of dynamic service composition pattern between WSR, Web services registry, WSP1, WSG, and WSP2. + +Y.2232(08)\_FIII.5 + +**Figure III.5 – Information flow of abstract service logic of composition pattern** + +For dynamic service composition, according to the abstract service logic of the composition services, the WSG transfers abstract service logic to concrete service logic by finding out the services that can fulfil the requirement to replace the service classes and creates invoking information for these services. Then, the WSG executes the concrete service logic to invoke the corresponding concrete services and returns the final execution result of the composition service to the WSR. + +# Bibliography + +- [b-ITU-T H.310] Recommendation ITU-T H.310 (1998), *Broadband audiovisual communication systems and terminals*. +- [ITU-T X.509] Recommendation ITU-T X.509 (2000) | ISO/IEC 9594-8:2001, *Information technology – Open Systems Interconnection – The Directory: Public-key and attribute certificate frameworks*. +- [b-ITU-T X.811] Recommendation ITU-T X.811 (1995) | ISO/IEC 10181-2:1996, *Information technology – Open Systems Interconnection – Security frameworks for open systems: Authentication framework*. +- [b-ITU-T X.812] Recommendation ITU-T X.812 (1995) | ISO/IEC 10181-3:1996, *Information technology – Open Systems Interconnection – Security frameworks for open systems: Access control framework*. +- [b-ITU-T X.1141] Recommendation ITU-T X.1141 (2006), *Security Assertion Markup Language (SAML 2.0)*. +- [b-ITU-T X.1142] Recommendation ITU-T X.1142 (2006), *eXtensible Access Control Markup Language (XACML 2.0)*. +- [b-ITU-T Y.110] Recommendation ITU-T Y.110 (1998), *Global Information Infrastructure principles and framework architecture*. +- [b-ITU-T Y.120] Recommendation ITU-T Y.120 (1998), *Global Information Infrastructure scenario methodology*. +- [b-ITU-T Y.1251] Recommendation ITU-T Y.1251 (2002), *General architectural model for interworking*. +- [b-ITU-T Y.2001] Recommendation ITU-T Y.2001 (2004), *General overview of NGN*. +- [b-ITU-T Y.2011] Recommendation ITU-T Y.2011 (2004), *General principles and general reference model for Next Generation Networks*. +- [b-ITU-T Z.100] Recommendation ITU-T Z.100 (2002), *Specification and Description Language (SDL)*. +- [b-ITU-T Y.2000-Sup.1] ITU-T Y.2000-series Recommendations – Supplement 1 (2006), *ITU-T Y.2000 series – Supplement on NGN release 1 scope*. +- [b-IETF 2828] IETF RFC 2828 (2000), *Internet Security Glossary*. +<> +- [b-IETF 4346] IETF RFC 4346 (2006), *The Transport Layer Security (TLS) Protocol Version 1.1*. <> +- [b-OASIS WSS 1.0] OASIS Web Services Security v1.0 (2004), *Web Services Security: SOAP Message Security 1.0, (WS-Security 2004)*. <> +- [b-OASIS WSS 1.1] OASIS Web Services Security v1.1 (2006), *Web Services Security: SOAP Message Security 1.1 (WS-Security 2004)*. <> +- [b-W3C XML] W3C Recommendation (2004), *XML Schema Part 0: Primer Second Edition*. <> + +- [b-WS-I BP 1.0] WS-I Basic Profile Version 1.0 (2004), *WS-I Basic Profile Version 1.0*. <> +- [b-WS-I BP 1.1] WS-I Basic Profile Version 1.1 (2006), *WS-I Basic Profile Version 1.1*. <> +- [b-WS-I BSP 1.0] WS-I Basic Security Profile Version 1.0 (2007), *Basic Security Profile Version 1.0*. <> + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|--------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/Y/T-REC-Y.2233-201006-I_PDF-E/043e64d41a3368d138ace3816fd26469_img.jpg b/marked/Y/T-REC-Y.2233-201006-I_PDF-E/043e64d41a3368d138ace3816fd26469_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..a8f524196caa65982f5f8881e0f001bb11c321ae --- /dev/null +++ b/marked/Y/T-REC-Y.2233-201006-I_PDF-E/043e64d41a3368d138ace3816fd26469_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:018a5bdf38b0f7ede7ffb39b38e8d224c88b358992e665ad8b001398431f6d57 +size 42706 diff --git a/marked/Y/T-REC-Y.2233-201006-I_PDF-E/11edb7fcedf09ac6a817f8d7b8c61eec_img.jpg b/marked/Y/T-REC-Y.2233-201006-I_PDF-E/11edb7fcedf09ac6a817f8d7b8c61eec_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..5aaf667b993417f3bfce36f6db26158996a05185 --- /dev/null +++ b/marked/Y/T-REC-Y.2233-201006-I_PDF-E/11edb7fcedf09ac6a817f8d7b8c61eec_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:2f566e2338fbebee466a99d8895eaa2fa463cfe08d7b89ca3013d4b90b6d1225 +size 55532 diff --git a/marked/Y/T-REC-Y.2233-201006-I_PDF-E/2bacc162a73d75c43a7f90715832bd13_img.jpg b/marked/Y/T-REC-Y.2233-201006-I_PDF-E/2bacc162a73d75c43a7f90715832bd13_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..2e2957160bec718ff587879c25fa520c0cf2e748 --- /dev/null +++ b/marked/Y/T-REC-Y.2233-201006-I_PDF-E/2bacc162a73d75c43a7f90715832bd13_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:7b87e942bd5e927593ebf7b1cd348d8a51b578804fb2b4414f2e8d607f61e1b6 +size 32960 diff --git a/marked/Y/T-REC-Y.2233-201006-I_PDF-E/399a5af4f606059626c92c92279d54b7_img.jpg b/marked/Y/T-REC-Y.2233-201006-I_PDF-E/399a5af4f606059626c92c92279d54b7_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..aab67fff3d50523e4fcc7b4482030a2cba865049 --- /dev/null +++ b/marked/Y/T-REC-Y.2233-201006-I_PDF-E/399a5af4f606059626c92c92279d54b7_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:1eccc76114ad0f3e5163d6330b0facbea701b17fe9ecbd27a12f282a0cb09668 +size 65204 diff --git a/marked/Y/T-REC-Y.2233-201006-I_PDF-E/705ee99c3c44fd2a1ea6a3348ce8878f_img.jpg b/marked/Y/T-REC-Y.2233-201006-I_PDF-E/705ee99c3c44fd2a1ea6a3348ce8878f_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..b47f1ee99ef20e177ce31c6e54ebb21eb6d0df13 --- /dev/null +++ b/marked/Y/T-REC-Y.2233-201006-I_PDF-E/705ee99c3c44fd2a1ea6a3348ce8878f_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:91c0e35640d1572ff5bda74155a2646053f2097f3526417bc8b515fa9d68a324 +size 23232 diff --git a/marked/Y/T-REC-Y.2233-201006-I_PDF-E/77959075c823bb5169480d7b8ff82a63_img.jpg b/marked/Y/T-REC-Y.2233-201006-I_PDF-E/77959075c823bb5169480d7b8ff82a63_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..45e3d58310fa80e0f99705b1faa0baac33c63306 --- /dev/null +++ b/marked/Y/T-REC-Y.2233-201006-I_PDF-E/77959075c823bb5169480d7b8ff82a63_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:4be0b404c0e2073ba3d202a81aa52dbd44e5d82a289016d3217a1094d342c3b6 +size 81239 diff --git a/marked/Y/T-REC-Y.2233-201006-I_PDF-E/7f5df81190b8dc50dad2604562ae0715_img.jpg b/marked/Y/T-REC-Y.2233-201006-I_PDF-E/7f5df81190b8dc50dad2604562ae0715_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..1ee494f62b08f444d99d85404b274460b7d28cff --- /dev/null +++ b/marked/Y/T-REC-Y.2233-201006-I_PDF-E/7f5df81190b8dc50dad2604562ae0715_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:6da50a3056145cd1f1d06bb8f71e23b36d078d9c8800a904073908d44f0f02e1 +size 46446 diff --git a/marked/Y/T-REC-Y.2233-201006-I_PDF-E/85e2327652d513a7fee8fdbf97ad06f1_img.jpg b/marked/Y/T-REC-Y.2233-201006-I_PDF-E/85e2327652d513a7fee8fdbf97ad06f1_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..e482ac772b2a1fb559630c53003942965bd2a100 --- /dev/null +++ b/marked/Y/T-REC-Y.2233-201006-I_PDF-E/85e2327652d513a7fee8fdbf97ad06f1_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:187b0fec6b6a763b836e457ea20c2f44567618a7f777a9156746ce4ab4f0a96d +size 82297 diff --git a/marked/Y/T-REC-Y.2233-201006-I_PDF-E/b235edb1dbe659e2782c9a0e47775ca4_img.jpg b/marked/Y/T-REC-Y.2233-201006-I_PDF-E/b235edb1dbe659e2782c9a0e47775ca4_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..33052246f7750b0ad5606ea2062c717416758c28 --- /dev/null +++ b/marked/Y/T-REC-Y.2233-201006-I_PDF-E/b235edb1dbe659e2782c9a0e47775ca4_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:0a35097b9f95a93484b76d86a31ed85adf3f7c4986be02ef8450660b9f761eec +size 21165 diff --git a/marked/Y/T-REC-Y.2233-201006-I_PDF-E/fa859e4e468bfb2710a94527f2c504af_img.jpg b/marked/Y/T-REC-Y.2233-201006-I_PDF-E/fa859e4e468bfb2710a94527f2c504af_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..796a6a638f16f304d49da1c95b1d240d463745ab --- /dev/null +++ b/marked/Y/T-REC-Y.2233-201006-I_PDF-E/fa859e4e468bfb2710a94527f2c504af_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:341674b33897c1d3a27459f5d346c3a3fd39429252f805d6751c9369404886b0 +size 139390 diff --git a/marked/Y/T-REC-Y.2234-200809-I_PDF-E/raw.md b/marked/Y/T-REC-Y.2234-200809-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..0f22c9d14d4ccb39a9257e8636af688888ed18c7 --- /dev/null +++ b/marked/Y/T-REC-Y.2234-200809-I_PDF-E/raw.md @@ -0,0 +1,889 @@ + + +I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +# Y.2234 + +(09/2008) + +SERIES Y: GLOBAL INFORMATION +INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS +AND NEXT-GENERATION NETWORKS + +Next Generation Networks – Service aspects: Service +capabilities and service architecture + +# --- **Open service environment capabilities for NGN** + +Recommendation ITU-T Y.2234 + +## ITU-T Y-SERIES RECOMMENDATIONS **GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT- GENERATION NETWORKS** + +## GLOBAL INFORMATION INFRASTRUCTURE + +| | | +|-------------------------------------------|-------------| +| General | Y.100–Y.199 | +| Services, applications and middleware | Y.200–Y.299 | +| Network aspects | Y.300–Y.399 | +| Interfaces and protocols | Y.400–Y.499 | +| Numbering, addressing and naming | Y.500–Y.599 | +| Operation, administration and maintenance | Y.600–Y.699 | +| Security | Y.700–Y.799 | +| Performances | Y.800–Y.899 | + +## INTERNET PROTOCOL ASPECTS + +| | | +|--------------------------------------------------------------------|---------------| +| General | Y.1000–Y.1099 | +| Services and applications | Y.1100–Y.1199 | +| Architecture, access, network capabilities and resource management | Y.1200–Y.1299 | +| Transport | Y.1300–Y.1399 | +| Interworking | Y.1400–Y.1499 | +| Quality of service and network performance | Y.1500–Y.1599 | +| Signalling | Y.1600–Y.1699 | +| Operation, administration and maintenance | Y.1700–Y.1799 | +| Charging | Y.1800–Y.1899 | + +## NEXT GENERATION NETWORKS + +| | | +|-----------------------------------------------------------------------|----------------------| +| Frameworks and functional architecture models | Y.2000–Y.2099 | +| Quality of Service and performance | Y.2100–Y.2199 | +| Service aspects: Service capabilities and service architecture | Y.2200–Y.2249 | +| Service aspects: Interoperability of services and networks in NGN | Y.2250–Y.2299 | +| Numbering, naming and addressing | Y.2300–Y.2399 | +| Network management | Y.2400–Y.2499 | +| Network control architectures and protocols | Y.2500–Y.2599 | +| Security | Y.2700–Y.2799 | +| Generalized mobility | Y.2800–Y.2899 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# **Recommendation ITU-T Y.2234** + +# **Open service environment capabilities for NGN** + +## **Summary** + +Recommendation ITU-T Y.2234 describes open service environment (OSE) capabilities for NGN. OSE capabilities are built on NGN release 1 capabilities with the aim to enable enhanced, flexible service creation and provisioning. This framework requires use of standard interfaces to ensure NGN OSE-based service reusability, portability across networks, as well as accessibility by NGN application providers and/or developers. OSE capabilities enable applications development using NGN OSE-based services for exposing the NGN capabilities. + +This Recommendation provides service requirements, functional requirements and architecture of open service environment capabilities. + +## **Source** + +Recommendation ITU-T Y.2234 was approved on 12 September 2008 by ITU-T Study Group 13 (2005-2008) under Recommendation ITU-T A.8 procedure. + +### **Keywords** + +Next generation networks (NGN), NGN OSE-based service, open service environment, open service environment capabilities, OSE, service-oriented architecture. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +### INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2009 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## CONTENTS + +| | | Page | +|---|---------------------------------------------------------------------------------------------------------|------| +| 1 | Scope ..... | 1 | +| 2 | References..... | 1 | +| 3 | Definitions ..... | 1 | +| | 3.1 Terms defined elsewhere..... | 1 | +| | 3.2 Terms defined in this Recommendation..... | 2 | +| 4 | Abbreviations and acronyms ..... | 2 | +| 5 | Conventions..... | 4 | +| 6 | Service requirements for open service environment capabilities ..... | 4 | +| 7 | Functional requirements for open service environment capabilities ..... | 5 | +| | 7.1 Service coordination functional requirements..... | 5 | +| | 7.2 Service discovery functional requirements ..... | 6 | +| | 7.3 Service registration functional requirements..... | 6 | +| | 7.4 Service management functional requirements..... | 6 | +| | 7.5 Service composition functional requirements ..... | 7 | +| | 7.6 Service development support functional requirements ..... | 7 | +| | 7.7 Interworking with service creation environment functional requirements..... | 7 | +| | 7.8 Policy enforcement functional requirements..... | 8 | +| 8 | Service architecture for open service environment capabilities ..... | 8 | +| | 8.1 OSE positioning within the NGN reference architecture ..... | 8 | +| | 8.2 Service architecture ..... | 10 | +| 9 | Security considerations..... | 12 | +| | Appendix I – Use cases for NGN open service environment ..... | 13 | +| | I.1 Introduction ..... | 13 | +| | I.2 Service registration and service discovery ..... | 13 | +| | I.3 BookItWell ..... | 14 | +| | I.4 IPTV new customer application ..... | 16 | +| | Appendix II – Relationship of SOA concepts with open service environment capabilities .... | 20 | +| | Appendix III – Relationship of standards in other SDOs with open service environment capabilities ..... | 21 | +| | III.1 Open Service Access (OSA)/Parlay ..... | 21 | +| | III.2 Open Mobile Alliance (OMA) ..... | 21 | +| | III.3 Organization for the Advancement of Structured Information Standards (OASIS)..... | 21 | +| | III.4 World Wide Web Consortium (W3C)..... | 22 | +| | III.5 Object Management Group (OMG) ..... | 22 | +| | III.6 TeleManagement Forum (TMF)..... | 23 | +| | III.7 Information sources for OSE capabilities..... | 24 | +| | Bibliography..... | 28 | + +# Introduction + +The ability to implement new functionalities in current networks may be limited or impossible due to the capabilities of the installed equipment. Software provisioning to implement new functionalities is essentially restricted to equipment vendors, since the existing or current application programming interfaces (APIs) are typically proprietary (i.e., not open) (Recommendation ITU-T Y.2201). NGN enables new capabilities and supports a wide range of emerging services, including services with advanced and complex functionalities. In response to a drive from application providers and/or developers to develop new applications and capabilities accessible via standard interfaces, there is an increasing need for NGN providers to cooperate in the development of standard application network interfaces (ANIs). Furthermore, software reusability and portability is encouraged to facilitate cost-effective development. + +The support of an open service environment within NGN aims to provide efficient and flexible capabilities based on the use of standard interfaces to NGN applications, thereby enabling applications to take full advantage of the NGN capabilities. + +Some general benefits of an open service environment are as follows (Recommendation ITU-T Y.2201). + +- Applications and capabilities can be easily developed by NGN providers as well as by application providers. +- Capabilities can be made portable and/or reusable across networks. +- Standard ANIs can accommodate interactions between NGN entities and applications. + +Within an open service environment, each capability is required to function either independently or in conjunction with other capabilities for the realization of applications. Each capability performs all corresponding service functions for the requesting entity. Applications may be provisioned over different networks, so the capabilities must be able to function independently from the underlying network technologies (Recommendation ITU-T Y.2201). + +# Recommendation ITU-T Y.2234 + +## Open service environment capabilities for NGN + +# 1 Scope + +The objective of this Recommendation is to define an open service environment (OSE) framework for NGN. This framework is built on NGN release 1 capabilities [ITU-T Y.2201] with the aim to enable enhanced, flexible service creation and provisioning. + +The use of standard interfaces will ensure NGN OSE-based service reusability, portability across networks, as well as accessibility by NGN application providers and/or developers. + +This Recommendation provides service requirements, functional requirements and architecture of open service environment capabilities. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- [ITU-T M.3060] Recommendation ITU-T M.3060/Y.2401 (2006), *Principles for the Management of Next Generation Networks*. +<> +- [ITU-T Y.2012] Recommendation ITU-T Y.2012 (2006), *Functional requirements and architecture of the NGN release 1*. +<> +- [ITU-T Y.2201] Recommendation ITU-T Y.2201 (2007), *NGN release 1 requirements*. +<> +- [ITU-T Y.2701] Recommendation ITU-T Y.2701 (2007), *Security requirements for NGN release 1*. +<> + +# 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 application network interface (ANI)** [ITU-T Y.2012]: Interface which provides a channel for interactions and exchanges between applications and NGN elements. The ANI offers capabilities and resources needed for the realization of applications. + +**3.1.2 application programming interface (API)** [b-ITU-T I.312]: An API provides a set of interfaces from an application environment to an execution environment. The execution environment provides services to the application environment. + +### 3.2 Terms defined in this Recommendation + +This Recommendation defines the following terms: + +**3.2.1 open service environment capabilities:** Capabilities provided by an open service environment to enable enhanced and flexible service creation and provisioning based on the use of standards interfaces. + +NOTE – Open service environment capabilities enable services reusability, portability across networks and accessibility by application providers and user applications in NGN. + +**3.2.2 service chain:** A set of coordinated services that occur in a specific sequence. + +**3.2.3 service composition:** Service composition is the capability of creating new services from other existing services. + +NOTE – NGN OSE-based services will be used as key building blocks to quickly create a composite service. Service composition can occur in a static or in a dynamic way. While in static composition, composite services are defined in advance, dynamic composition sends the request for service discovery using the service description to find the needed services and composes the services during run time. + +**3.2.4 service coordination:** The ability to manage the relationships and interactions among services to provide a "service chain", as well as among services and applications. + +**3.2.5 service development support:** Service development support provides an environment for service creation, development and maintenance. + +**3.2.6 service discovery:** Service discovery performs a search against all registered services and provides the related service information. + +**3.2.7 service management:** Service management provides the overall service managing functions such as service monitoring, service tracking and unexpected failure control. + +**3.2.8 service registration:** Service registration manages the information about services and maintains the most up-to-date information. + +# 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|------------|-------------------------------------------------------------| +| ANI | Application Network Interface | +| API | Application Programming Interface | +| APL-GW-FE | Application Gateway Functional Entity | +| APL-SCM-FE | Application Service Coordination Manager Functional Entity | +| ASF | Application Support Functions | +| ASF&SSF | Application Support Functions and Service Support Functions | +| AS-FE | Application Support Functional Entity | +| BPDM | Business Process Definition Metamodel | +| BPEL | Business Process Execution Language | +| BPMN | Business Process Modelling Notation | +| BPRI | Business Process Run-time Interface | +| BSS | Billing Support System | +| CAMEL | Customized Application for Mobile network Enhanced Logic | +| CDL | Choreography Description Language | + +| | | +|----------|---------------------------------------------------| +| DPE | Device Profile Evolution | +| EAI | External Authoring Interface | +| ebXML | electronic business eXtensible markup language | +| EDOC | Enterprise Distributed Object Computing | +| EJB | Enterprise JavaBeans | +| eTOM | enhanced Telecom Operations Map | +| FE | Functional Entity | +| GPM | Global Management Program | +| GPS | Global Positioning System | +| HDTV | High Definition Television | +| IMS | Internet protocol Multimedia Subsystem | +| IN | Intelligent Network | +| INAP | Intelligent Network Application Protocol | +| IP | Internet Protocol | +| IPTV | Internet Protocol Television | +| MOF | Meta Object Facility | +| MTNM | Multi-Technology Network Management | +| MTOSI | Multi-Technology Operations System Interfaces | +| NGN | Next Generation Network | +| NGOSS | New Generation Operations Systems and Software | +| NNI | Network-to-Network Interface | +| OSA | Open Service Access | +| OSE | Open Service Environment | +| OSPE | Open Mobile Alliance Service Provider Environment | +| OSS | Operations Support System(s) | +| OSS/J | Operations Support System through Java initiative | +| OWSER | Open Mobile Alliance Web Service Enabler | +| P2P | Peer-to-Peer | +| PEEM | Policy Evaluation, Enforcement and Management | +| QoS | Quality of Service | +| RAS | Reusable Asset Specifications | +| RIM | Registry Information Model | +| S-CSC-FE | Serving Call Session Control Functional Entity | +| SCA | Service Component Architecture | +| SCF | Service Control Functions | +| SCP | Service Control Point | +| SEC_CF | Security Common Function | + +| | | +|-------|---------------------------------------------------------------| +| SID | Shared Information/Data | +| SOA | Service Oriented Architecture | +| SOAP | Simple Object Access Protocol | +| SS-FE | Service Switching Functional Entity | +| SSF | Service Support Functions | +| UDDI | Universal Description, Discovery and Integration | +| UML | Unified Modelling Language | +| UPMS | Unified Modelling Language Profile and Metamodel for Services | +| VoD | Video on Demand | +| WIN | Wireless Intelligent Network | +| WSDL | Web Services Description Language | +| WSDM | Web Services Distributed Management | +| XML | eXtensible Markup Language | + +# 5 Conventions + +None. + +# 6 Service requirements for open service environment capabilities + +This clause describes the service requirements of open service environment capabilities for NGN. The NGN open service environment is required to: + +- Provide standard APIs for application providers and/or developers to create and introduce applications quickly and seamlessly. +NOTE – Requirements for the standard APIs specified in this Recommendation are at the control level and they do not address media information such as voice and video. +- Provide service level interoperability among different networks, operating systems and programming languages (e.g., web services are an example of enabling technology for providing service level interoperability). +- Support service independence from NGN providers and manufacturers [ITU-T Y.2201]: + - Functionalities, operations and management of applications are recommended to be all independent from the underlying NGN providers' technologies and infrastructures. + - Multi-vendor implementations of NGN open service environment are recommended to be supported. +- Support OSE capabilities based on NGN providers' capabilities. However, OSE capabilities based on application providers' capabilities are not supported in this version of this Recommendation. +- Support location, network and protocol transparency [ITU-T Y.2201]: + - In a distributed environment, application providers and/or developers are recommended to be able to access NGN OSE-based services from anywhere, regardless of their physical location. + - NGN open service environment capabilities are recommended to allow services to be technology- and terminal-agnostic. + +- Protocol transparency is required to be achieved by providing standard protocol programming interface tools for realizing independent service control processes and shielding complex network technical details to the open service environment [ITU-T Y.2201]. +- Provide capabilities for coordinating services among themselves and services with applications. +- Support service discovery capabilities to allow users and their devices to discover the services, applications, and other network information and resources of their interest [ITU-T Y.2201]. In addition, discovery mechanisms for services or components of multiple application providers are recommended to be provided. +- Provide the means to manage the registration of capabilities, services and applications. The technology choice is required to ensure functions for service registration and deregistration, including configuration, activation, publication [ITU-T Y.2201]. +- Provide the following service management capabilities: + - service tracking; + - update management; + - auditing; + - version control; + - logging, e.g., provide a record of the history of services; + - access control management; + - statistical analysis of service registration and utilization. +- Support NGN service reuse by providing service composition capability. +- Support of a service composition language. +- Offer a development support environment which supports construction, trialling, deployment and removal of applications [ITU-T Y.2201]. +- Allow interworking with service creation environments and network entities for creation and provisioning of applications and services [ITU-T Y.2201]. +- Provide a secure access to the NGN capabilities in alignment with the general NGN security requirements as specified in [ITU-T Y.2201]. +- Support policy enforcement capability for resource protection and management, and service personalization. + +# **7 Functional requirements for open service environment capabilities** + +This clause describes functional requirements specific to the support of NGN open service environment capabilities. OSE capabilities consist of service coordination, service discovery, service registration, service management, service composition, service development support, interworking with service creation environments and policy enforcement. + +### **7.1 Service coordination functional requirements** + +The NGN service coordination functions are required to: + +- Provide coordination of applications and services with capabilities [ITU-T Y.2201]. +- Provide the tracking of NGN capabilities or service components from various application providers, and the relationship between these capabilities or service components (adapted from [ITU-T Y.2201]). + +- Support the information on state change of capabilities or service components for applications and services [ITU-T Y.2201]. + +### **7.2 Service discovery functional requirements** + +The NGN service discovery functions are required to: + +- Provide service discovery for physically distributed NGN services. +- Support a variety of discovering criteria (e.g., specific field-based discovery, classification system-based discovery). An example of discovering criteria is implemented in the universal description, discovery and integration (UDDI) specification of web services framework. +- Use user and device profile information for discovering the correct service. +- Allow users to discover user-interest services, device-interest services and network information. +- Support a variety of scoping criteria (e.g., location and cost) to provide appropriate scaling, with appropriate mechanisms to ensure security and privacy (this allows support of customized discovery for a wide range of scenarios). +- Use a variety of approaches for discovering services such as client-server, P2P, combination of client-server and P2P. +- Support appropriate mechanisms to ensure security and privacy [ITU-T Y.2201]. +- Take into account scalability (e.g., broadcast mechanisms are recommended to be avoided) [ITU-T Y.2201]. + +### **7.3 Service registration functional requirements** + +The NGN service registration functions are required to: + +- Provide service registration, including configuration, activation, publication and service deregistration. +- Provide a variety of service registration features (e.g., manual, autonomous) for NGN services. +- Support a variety of registration parameters, including mandatory and optional parameters. + +The NGN service registration functions may support: + +- Registration services in centralized and de-centralized ways. +- Multiple concurrent service registrations. + +### **7.4 Service management functional requirements** + +The NGN service management functions are required to: + +- Provide a monitoring function of registered services for availability and predicted response time. NGN services and user applications might need to use monitoring information for the availability or predicted response time of target services before executing services. +- Provide managing functions of QoS information about registered NGN services such as accessibility, performance, integrity, reliability, etc. +- Provide a version management function to NGN services for interoperability. +- Provide notification service functions for updated services. +- Provide failure detection and recovery functions for unexpected failures. + +- Provide service tracking management functions to capture and log all relevant information for each component within a service chain. Service tracking is recommended to allow for an association among the captured data associated with a specific service. Service tracking is required to enable tracking of capabilities or components of multiple third parties, and the relationships between these capabilities or components. +- Provide a service substitution function that considers various kinds of factors to users. It is required to provide mechanisms to capture a set of information including terminal capability, network situation, user preference and substitution policy; and judge whether to substitute the service or not based on the captured information. If there is a need to substitute the service, this function will substitute it. +- Provide service access control functions to control the accessibility of a specific service by applications (the service access control function provides the necessary authentication and authorization actions required to ensure that the application has appropriate access rights for the requested service). +- Provide statistical analysis functions to analyse service registration and utilization information (e.g., number of registered services, utilization frequency of registered services and number of applications using registered services). +- Provide an auditing function to review the overall operations of open service environment capabilities during a specific period required by the auditor. + +NOTE – The relationship with requirements in [ITU-T M.3060] needs to be considered in the future. + +### **7.5 Service composition functional requirements** + +The NGN service composition functions are required to: + +- Provide a composition language that describes the interaction among services. Additionally, the composition language is recommended to support expression capabilities for describing the composition logic among services. +- Support the composition of services statically or dynamically (i.e., for the static type, the services are composed during service design; while for the dynamic type, the services are composed during service runtime). + +### **7.6 Service development support functional requirements** + +The NGN service development support functions are required to: + +- Support service re-use and allow for service interchangeability [ITU-T Y.2201]. +- Support mixing-and-matching of services by management of interfaces and consistent semantics of shared data/schema across these services [ITU-T Y.2201]. +- Support the full life cycle of services, ranging from installation, configuration, administration, publishing, versioning, maintenance and removal [ITU-T Y.2201]. +- Support delivery-agnostic application design to allow applications to be implemented without requiring re-design for each subsequent development scenario [ITU-T Y.2201]. +- Support tracking of dependencies among services [ITU-T Y.2201]. + +### **7.7 Interworking with service creation environment functional requirements** + +The NGN service creation environment interworking functions are required to: + +- Support the following three classes of service creation environments [ITU-T Y.2201]: + - Open service creation environment (examples of this class of environment using ANI include OSA/Parlay, Parlay X, OMA). + - IP multimedia subsystem (IMS)-based service creation environment. + +- Intelligent network (IN)-based service creation environment (examples of relevant interface protocols for this class of environment include IN application protocol (INAP), customized application for mobile network enhanced logic (CAMEL) and wireless intelligent network (WIN)). + +### **7.8 Policy enforcement functional requirements** + +The NGN policy enforcement functions are required to: + +- Provide a description language to express various types of policy rules such as those related to authorization, charging, service level agreement and logging. This language is recommended to support policy re-use. +- Provide a policy execution framework to interpret and execute the policies. +- Protect services from unauthorized users' requests and manage requests based on the policy rules. +- Support the selection of appropriate services for service composition to respond to the needs and preferences of a user or a group of users. + +# **8 Service architecture for open service environment capabilities** + +This clause describes service architecture for the support of open service environment capabilities in NGN. This architecture is based on the NGN release 1 functional architecture [ITU-T Y.2012]. + +### **8.1 OSE positioning within the NGN reference architecture** + +Figure 1 is an extension of Figure 1 in [ITU-T Y.2012]. It shows an extended NGN architecture enabling support of open service environment capabilities. + +The functional group identified as "OSE" in Figure 1 provides an open service environment for NGN and enables NGN applications to implement enhanced services that make use of NGN capabilities. The OSE functional group is positioned inside the application support functions and service support functions of the NGN service stratum. + +NOTE – Applications in Figure 1 are provided by various application providers and/or developers and are not intended to be limited to a single application provider or developer. + +![Figure 1 – Extended NGN architecture positioning the OSE. The diagram shows a layered architecture. At the top is 'Applications'. Below it is the 'Service stratum' (green background) containing 'OSE' (green box), 'Application Support Functions & Service Support Functions', and 'Service Control Functions' (which includes 'Service User Profiles'). Below the Service stratum is the 'Transport stratum' (yellow background) containing 'Transport Control Functions' (with 'Network Attachment Control Functions' and 'Transport User Profiles') and 'Resource and Admission Control Functions'. At the bottom is 'Transport Functions'. To the left is a vertical pink bar for 'Management Functions'. To the right is a box for 'Other Networks'. Interfaces are shown: 'ANI' (red solid line) between Applications and OSE; 'UNI' (blue solid line) between End-user Functions and Transport Functions; 'NNI' (blue solid line) between Transport Functions and Other Networks. Dashed lines represent control: black dashed for 'Control except OSE', green dashed for 'Management', and red dashed for 'Control for OSE'. End-user Functions and Other Networks are connected to the Management Functions bar via green dashed lines.](33ed1f9b27c7c21c797aa928b0f06851_img.jpg) + +Figure 1 – Extended NGN architecture positioning the OSE. The diagram shows a layered architecture. At the top is 'Applications'. Below it is the 'Service stratum' (green background) containing 'OSE' (green box), 'Application Support Functions & Service Support Functions', and 'Service Control Functions' (which includes 'Service User Profiles'). Below the Service stratum is the 'Transport stratum' (yellow background) containing 'Transport Control Functions' (with 'Network Attachment Control Functions' and 'Transport User Profiles') and 'Resource and Admission Control Functions'. At the bottom is 'Transport Functions'. To the left is a vertical pink bar for 'Management Functions'. To the right is a box for 'Other Networks'. Interfaces are shown: 'ANI' (red solid line) between Applications and OSE; 'UNI' (blue solid line) between End-user Functions and Transport Functions; 'NNI' (blue solid line) between Transport Functions and Other Networks. Dashed lines represent control: black dashed for 'Control except OSE', green dashed for 'Management', and red dashed for 'Control for OSE'. End-user Functions and Other Networks are connected to the Management Functions bar via green dashed lines. + +**Figure 1 – Extended NGN architecture positioning the OSE** + +"Control for OSE" in Figure 1 represents the control level interfaces between applications and OSE. These interfaces do not support exchange of media information such as voice and video. + +"Control except OSE" in Figure 1 represents the interactions and exchanges between applications and NGN services which are external to the interactions and exchanges between applications and OSE. + +Figure 2 shows the functional components constituting the OSE functional group: service coordination, service discovery, service registration, service management, service composition, service development support, interworking with service creation environments, and policy enforcement. + +![Diagram showing the functional components of the OSE functional group. At the top is a light blue box labeled 'Applications'. Below it is a thick red horizontal line labeled 'ANI' on the right. A dashed red vertical line connects 'Applications' to a large rounded rectangle labeled 'OSE' on its top-left corner. Inside the 'OSE' rectangle are eight light blue rounded boxes stacked vertically: 'Service Coordination', 'Service Discovery', 'Service Registration', 'Service Management', 'Service Composition', 'Service Development Support', 'Interworking with Service Creation Environments', and 'Policy Enforcement'. A dashed red vertical line connects the bottom of the 'OSE' rectangle to the text 'Other ASF&SSF FEs' at the bottom.](fa859e4e468bfb2710a94527f2c504af_img.jpg) + +``` + +graph TD + Applications[Applications] + ANI[ANI] + subgraph OSE [OSE] + SC[Service Coordination] + SD[Service Discovery] + SR[Service Registration] + SM[Service Management] + SCOMP[Service Composition] + SDDS[Service Development Support] + ISC[Interworking with Service Creation Environments] + PE[Policy Enforcement] + end + Other[Other ASF&SSF FEs] + + Applications --- ANI + Applications -.- OSE + OSE -.- Other + +``` + +Diagram showing the functional components of the OSE functional group. At the top is a light blue box labeled 'Applications'. Below it is a thick red horizontal line labeled 'ANI' on the right. A dashed red vertical line connects 'Applications' to a large rounded rectangle labeled 'OSE' on its top-left corner. Inside the 'OSE' rectangle are eight light blue rounded boxes stacked vertically: 'Service Coordination', 'Service Discovery', 'Service Registration', 'Service Management', 'Service Composition', 'Service Development Support', 'Interworking with Service Creation Environments', and 'Policy Enforcement'. A dashed red vertical line connects the bottom of the 'OSE' rectangle to the text 'Other ASF&SSF FEs' at the bottom. + +**Figure 2 – Functional components of the OSE functional group** + +### 8.2 Service architecture + +This clause provides details of the service architecture related to the OSE functional group. + +Figure 3 is an extended NGN architecture positioning the OSE with an expanded view of the OSE functional group. + +![Figure 3: Extended NGN architecture positioning the OSE with expanded view of the OSE functional group. The diagram shows a layered architecture. At the top is 'Applications' connected to 'ANI'. Below is the 'Service stratum' (green box) containing 'Application Support Functions & Service Support Functions' (which includes the 'OSE' group: Service Management, Service Discovery, Service Registration, Service Coordination, Service Development Support, Service Composition, and Interworking with Service Creation Environment), and 'Service Control Functions' (containing 'Service User Profiles'). Below the Service stratum is the 'Transport stratum' (yellow box) containing 'Transport Control Functions' (with 'Network Attachment Control Functions' and 'Transport User Profiles') and 'Resource and Admission Control Functions'. At the bottom are 'End-user Functions' and 'Other Networks'. A vertical pink bar on the left represents 'Management Functions'. Interfaces are shown: 'UNI' (User Network Interface) between End-user Functions and the Service stratum; 'NNI' (Network Network Interface) between the Transport stratum and Other Networks; and 'ANI' (Application Network Interface) between Applications and the Service stratum. A legend indicates: dashed black line for 'Control except OSE', solid blue line for 'Media', dashed green line for 'Management', and dashed red line for 'Control for OSE'.](8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg) + +Figure 3: Extended NGN architecture positioning the OSE with expanded view of the OSE functional group. The diagram shows a layered architecture. At the top is 'Applications' connected to 'ANI'. Below is the 'Service stratum' (green box) containing 'Application Support Functions & Service Support Functions' (which includes the 'OSE' group: Service Management, Service Discovery, Service Registration, Service Coordination, Service Development Support, Service Composition, and Interworking with Service Creation Environment), and 'Service Control Functions' (containing 'Service User Profiles'). Below the Service stratum is the 'Transport stratum' (yellow box) containing 'Transport Control Functions' (with 'Network Attachment Control Functions' and 'Transport User Profiles') and 'Resource and Admission Control Functions'. At the bottom are 'End-user Functions' and 'Other Networks'. A vertical pink bar on the left represents 'Management Functions'. Interfaces are shown: 'UNI' (User Network Interface) between End-user Functions and the Service stratum; 'NNI' (Network Network Interface) between the Transport stratum and Other Networks; and 'ANI' (Application Network Interface) between Applications and the Service stratum. A legend indicates: dashed black line for 'Control except OSE', solid blue line for 'Media', dashed green line for 'Management', and dashed red line for 'Control for OSE'. + +**Figure 3 – Extended NGN architecture positioning the OSE with expanded view of the OSE functional group** + +#### 8.2.1 Relationship between OSE functional components and functional entities of the NGN release 1 functional architecture + +OSE functional components use standard interfaces to NGN applications and user services enabling applications to be implemented taking full advantage of NGN capabilities. + +According to [ITU-T Y.2012], the application gateway functional entity (APL-GW-FE) in ASF&SSF (application support functions and service support functions) is the interworking entity between various functions of NGN and all external application servers and service enablers. The application service coordination manager functional entity (APL-SCM-FE) manages interactions between multiple application services (or servers). And the functional entities of ASF&SSF might interwork with each other via APL-SCM-FE to provide services to the end users. + +NOTE – The relationship of OSE service management functions and management functions in Figure 3 needs to be defined and described in the future. In so doing, the principles for the management of NGN in [ITU-T M.3060] should be applied. + +Table 1 provides a set of candidate options for the mapping of OSE functional components into [ITU-T Y.2012] ASF&SSF functional entities. + +**Table 1 – Mapping of OSE functional components into [ITU-T Y.2012] +ASF&SSF functional entities** + +| | APL-GW-FE | APL-SCM-FE | AS-FE | SS-FE | New FE
(currently not
identified) | +|----------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------|--------------------------------------------------| +| Mapping of
OSE functional
components
into ASF&SSF
FEs | Serves as an interworking entity between the applications, and services and capabilities of the NGN (adapted from [ITU-T Y.2012]) | Manages interactions between multiple application services (or servers) [ITU-T Y.2012] | Supports generic application server functions including hosting and executing services [ITU-T Y.2012] | Provides access and interworking to a legacy IN SCP [ITU-T Y.2012] | | +| Service coordination | Not applicable | Optional | Not applicable | Not applicable | Optional | +| Service discovery | Optional | Not applicable | Not applicable | Not applicable | Optional | +| Service registration | Optional | Not applicable | Not applicable | Not applicable | Optional | +| Service management | Optional | Not applicable | Not applicable | Not applicable | Optional | +| Service composition | Not applicable | Optional | Not applicable | Not applicable | Optional | +| Service development support | Optional | Not applicable | Not applicable | Not applicable | Optional | +| Interworking with service creation environments | Optional | Not applicable | Optional | Optional | Optional | +| Policy enforcement | Optional | Optional | Not applicable | Not applicable | Optional | + +# 9 Security considerations + +In the interaction of the open service environment capabilities with NGN applications, it is recommended that the security requirements of [ITU-T Y.2201] and [ITU-T Y.2701] be taken into consideration, including the following dimensions of NGN security: access control, authentication, non-repudiation, data confidentiality, communication security, data integrity, availability and privacy. + +# Appendix I + +## Use cases for NGN open service environment + +(This appendix does not form an integral part of this Recommendation) + +### I.1 Introduction + +As next generation networks (NGNs) evolve and are deployed, they are expected to enable an open service environment that will foster service creation. This appendix identifies a number of service or service feature use cases whose implementation and deployment would benefit from support of an NGN open service environment. + +### I.2 Service registration and service discovery + +![Figure I.1: Interactions between applications, NGN services and OSE capabilities. The diagram illustrates the architecture of an NGN open service environment (OSE) and its interactions with applications, management functions, and other networks.](a734898ce18e972938949637c32a34f4_img.jpg) + +The diagram illustrates the interactions between applications, NGN services, and OSE capabilities. It is structured into several layers and components: + +- Applications:** Located at the top, interacting with the OSE via the ANI (Application Network Interface). +- OSE (Open Service Environment):** A central component containing: + - Service Management:** Includes Service Discovery, Service Registration, and Service Coordination. + - Policy Enforcement:** Interacts with Service Management. + - Service Development Support:** Includes Service Composition and Interworking with Service Creation Environment. +- Application Support Functions & Service Support Functions:** A layer below the OSE, containing: + - Service User Profiles:** Interacts with the OSE via (1). + - Service Control Functions:** Interacts with the OSE via (6). +- Service stratum:** A layer below the Application Support Functions, containing: + - Network Attachment Control Functions:** Includes Transport User Profiles. + - Resource and Admission Control Functions:** Interacts with the Service Control Functions. +- Transport Control Functions:** A layer below the Service stratum, containing: + - Transport Functions:** Interacts with the Transport Control Functions. +- Management Functions:** A vertical bar on the left, interacting with the OSE via (2), (3), (4), and (5). +- End-user Functions:** Interacts with the OSE via the UNI (User Network Interface). +- Other Networks:** Interacts with the OSE via the NNI (Network Network Interface). + +Legend: + +- Control except OSE +- Media +- Management +- Control for OSE + +Figure I.1: Interactions between applications, NGN services and OSE capabilities. The diagram illustrates the architecture of an NGN open service environment (OSE) and its interactions with applications, management functions, and other networks. + +Figure I.1 – Interactions between applications, NGN services and OSE capabilities + +This clause describes a use case of how applications can use NGN services with open service environment capabilities. The scenario is outlined in Figure I.1 and it is assumed that the authentication function of the NGN service stratum is provided to the application through the OSE. + +The process associated with this use case is the following: + +At first, NGN services in both service and transport strata and new services created via service development support are registered (step 1). Next, service registration processes this information and generates information for service discovery and management. + +When the application contacts the open service environment capabilities, the application is at first authenticated and authorized from service management to usage of NGN services (step 2). After the application invokes service discovery, it obtains a list of the available services and selects one among them. Then it requests the associated interface information from service discovery (step 3). Service discovery returns the interface (step 4). From this moment onwards, the application is able to use the service (steps 5 and 6). + +### I.3 BookItWell + +![Diagram illustrating interactions between a service provider and service consumers. A Service provider (containing Capabilities) registers with a Registry (Step 1). Consumers (A, ..., Z) query the Registry (Step 2) and then interact with the Service provider (Step 3). A Management interface is also shown.](5445597cceefaca1ac89e710fe339325_img.jpg) + +``` + +graph TD + SP[Service provider +Capabilities] -- 1 --> R[Registry] + R -- 2 --> C[Consumer A +... +Consumer Z] + C -- 3 --> SP + MI[Management interface] --- SP + +``` + +Diagram illustrating interactions between a service provider and service consumers. A Service provider (containing Capabilities) registers with a Registry (Step 1). Consumers (A, ..., Z) query the Registry (Step 2) and then interact with the Service provider (Step 3). A Management interface is also shown. + +**Figure I.2 – Interactions between service provider and service consumers** + +NGN open service environment comprises several major capabilities that allow potential service consumers to locate and invoke services (i.e., based on OSE service registration and service discovery capabilities). Service providers make their services visible by publishing service descriptions in a registry (1). Typically, the universal description, discovery and integration (UDDI) protocol is used between a service provider and the registry. A potential consumer of the service also uses the UDDI protocol to ask the registry about available services and receives the appropriate service descriptions from the registry (2). These descriptions contain sufficient information to allow the consumer to interact with the service provider to cause the desired real-world effect (3). The syntax of this interface is normally specified using the web services description language (WSDL). A management interface enables the service owner to configure, monitor and take service capabilities through their lifecycles from introduction through depreciation to removal in an orderly manner. This interface may use such protocols as web services distributed management (WSDM) and WS management. + +People driving long distances in their car understand the annoyance associated with trying to find a suitable hotel at the end of a long day of travel if they were not able to arrange in advance a place for the evening. Such a search would involve obtaining local maps and driving off the main road to look for hotels with vacancies. Add some small children in the back seat asking "are we there yet?" and the imaginatively named "BookItWell" service provided by "DriveALot Inc." could be the answer (although the service is fictitious, all of the components exist and several related services are already available from various service providers). + +As illustrated in Figure I.2, the BookItWell service can be built by combining a number of services provided independently by different companies, including those for hotel booking, weather forecasting, location, instant messaging, route calculation and billing. + +Each evening, after taking into account the consumer location, the weather forecast and pre-loaded hotel preferences, the service locates and books a suitable hotel room for the consumer and sends a message, giving directions to the hotel, to his/her cellular telephone, or programs the consumer car's global positioning system (GPS) with the appropriate information. + +BookItWell simply buys access to the underlying services. Whether the location service is based on cellular telephone triangulation or GPS is irrelevant to BookItWell as long as the contracted service quality (up-time, accuracy, precision, etc.) is maintained. To allow BookItWell to combine the underlying services easily, it is essential that each service provides details of its interface in a standard format. + +BookItWell makes use of two weather forecasting services and chooses the one that is cheaper for a particular request. In this case, the underlying services not only make their interfaces available, but also provide details of their costs and coverage. + +With the exception of the weather forecasting service, all the components (i.e., underlying services) of the BookItWell service are composed based on static service composition. Static service composition invokes the service components directly based on composite service logic. + +The invocation of a given weather forecasting service is done in a dynamic way. Service composition makes use of service discovery to identify the preferred service component, based on the service request, and then invokes the selected one. In the case of the BookItWell service, the criterion of selection is the cost of the invocation in a specific context. In general, the service request for dynamic service composition includes the description of the required service, and the information can be mapped to more than one exact service component. When a consumer invokes one of these capabilities through an interaction with the provider (link #3 in Figure I.2), some real-world effect occurs. In this use case, when the BookItWell consumer interacts with the hotel booking service, a room is booked – a real-world effect. Note that BookItWell is both a provider (to DriveALot's subscribers) and a consumer (of another provider's route calculation service). A capability together with its specification, contract and real-world effect is defined as a service in this context. + +In this use case, a company has developed a route calculation service. This service has a contract, interface specification and sufficient security to ensure that it is used only by authorized consumers. + +Providers have to make their services visible to allow potential consumers to discover them (using OSE service registration capability). They do this by publishing (exposing) a service description containing information about three aspects of the service: its behaviour, its interface, and its policies and contracts. In this use case, the two potential suppliers of weather forecasting services advertise the service description of their services, allowing BookItWell to discover them and interact with them. + +The interface description includes the specific protocols, commands and information exchange by which actions are initiated that result in real-world effects, as specified through the service functionality portion of the service description. Service providers and service consumers are together known as service participants. + +Once a service has been made visible, it can be combined with other visible services to create a higher-level or orchestrated service that typically implements a particular business process. + +In this use case, DriveALot has orchestrated (see Appendix II for definition of orchestration) using the OSE service composition capability to combine underlying services into a business flow known as BookItWell. Each of the underlying services that are used may themselves be composed of lower-level services, but this is of no interest to DriveALot. + +In addition to orchestration, new higher-level services can be created from simpler ones through choreography (see Appendix II for definition) using the OSE service composition capability. Although there are several differences between orchestration and choreography, the primary + +outward difference lies in where the state of the flow is held: in the case of orchestration, it is held in a central controller; in the case of choreography, it is held in each invoked service. + +In this example orchestrated service, when the weather-forecasting system is invoked, it may take several seconds to respond. During this time, the state of the composite service is stored centrally so that the response from the weather forecast service is expected when it arrives and the next step in the process can be activated. In a choreographed service, on the other hand, this state information would be carried through each of the various service providers. + +The interactions of the type shown in Figure I.3 (invoke service X, and if that fails or if it is, for example, a Tuesday, then invoke service Y, then invoke service Z, and so on) are typically drawn using a graphical editor and then converted into a formal language. In the case of orchestration, they could be converted into business process execution language (BPEL); and in the case of choreography, they could be converted into choreography description language (CDL). + +![Figure I.3 – BookItWell service example diagram](e180f2b5fcbe8001554a7c0677cd3f82_img.jpg) + +The diagram illustrates the BookItWell service architecture. A central black box labeled 'BookItWell' acts as the orchestrator. It is connected to a 'Customer' (represented by a circle) and a 'Service Configuration' (represented by a rectangle). Below the central box, there are seven service components: 'Hotel Booking', 'Weather Forecast A', 'Weather Forecast B', 'Location', 'Instant Messaging', 'Route Calculation', and 'Billing'. Solid lines connect the 'BookItWell' box to each of these seven services. Additionally, a solid line connects the 'Customer' to the 'BookItWell' box. A dashed line with an arrow points from the 'BookItWell' box to 'Weather Forecast A', and another dashed line with an arrow points from 'Weather Forecast A' to 'Weather Forecast B', indicating a conditional or sequential flow between these two services. + +Figure I.3 – BookItWell service example diagram + +**Figure I.3 – BookItWell service example** + +### **I.4 IPTV new customer application** + +This clause provides an IPTV new customer application use case. This use case utilizes a particular IPTV customer service as an example to show how a service could be created in an open environment. This example is telco-centric and shows how complex and sophisticated services (created based on the OSE service development support capability) can be delivered to end users using OSE service composition capability provided by various vendors and components via the OSE service registration capability. + +The service can be plotted using a layered architecture. A simplified version of this architecture is shown in Figure I.4 and consists of a component/vendor layer and an OSE service composition capability layer. This layered architecture can be expanded by composing additional OSE service composition layers on top of existing service layers. The services in the higher layer (built using the OSE service composition capability) may be created using a subset and/or abstraction of services from the lower layer(s) (using the OSE service registration). + +![Figure I.4 – Telco service layered architecture. This diagram shows a two-layer architecture. The top layer is the 'Service Composition Layer' containing 'Service Center 1' and 'Service Center 2'. The bottom layer is the 'Component/Vendor Layer' containing components 'A', 'B', and 'C'. Service Center 1 connects to A and B. Service Center 2 connects to B and C. Each component (A, B, C) is connected to a database icon. A dashed line separates the two layers. A small computer icon is shown at the top left, connected to Service Center 1.](c914f51f4427bc672dd0526cfc90ebe9_img.jpg) + +Figure I.4 – Telco service layered architecture. This diagram shows a two-layer architecture. The top layer is the 'Service Composition Layer' containing 'Service Center 1' and 'Service Center 2'. The bottom layer is the 'Component/Vendor Layer' containing components 'A', 'B', and 'C'. Service Center 1 connects to A and B. Service Center 2 connects to B and C. Each component (A, B, C) is connected to a database icon. A dashed line separates the two layers. A small computer icon is shown at the top left, connected to Service Center 1. + +**Figure I.4 – Telco service layered architecture** + +In the architecture shown in Figure I.4, we assume that A, B and C can exchange workflow information, thereby linking the higher-level service with the corresponding device/component models. Using this layered concept as the approach to service development, an IPTV use case is developed. + +The use case presented is an IPTV new customer processing service. In this use case, the telco composite service layer creates an IPTV new customer processing service from the underlying services and management functions provided by various IPTV services and financial services. This new customer service is essentially an ordered invocation of a business process which involves several steps: credit check, search for IPTV service providers, set-up vendor-level IPTV services and set-up financial information services. + +![Figure I.5 – IPTV use case. This diagram illustrates a workflow for a 'Telco new IPTV customer service'. The main process flow is: 1. Start (computer icon) -> 1. Credit check (A) -> 4. Search IPTV provider (B) -> 7. VoD (C) -> 10. HDTV (D) -> 13. Setup IPTV account (E) -> 16. Done. A 'Failed, reject application' box is connected to steps 1, 4, 7, 10, and 13. Below the main flow are five external services: 1. Bank credit centre (a) connected to step 1 via '2 Credit check' and '3 OK'. 2. WS registry (b) connected to step 4 via '5 Search IPTV service' and '6 Other term'. 3. A's IPTV solution (c) connected to step 7 via '8 Add new customer' and '9 OK'. 4. B's IPTV solution (d) connected to step 10 via '11 Add new customer' and '12 OK'. 5. Bank accounting service (e) connected to step 13 via '14 Setup auto-withdraw' and '15 OK'. A 'Vendor VoD' box is connected to step 7 via 'Add user'.](844077b3034f0030b404207db0ad76b4_img.jpg) + +Figure I.5 – IPTV use case. This diagram illustrates a workflow for a 'Telco new IPTV customer service'. The main process flow is: 1. Start (computer icon) -> 1. Credit check (A) -> 4. Search IPTV provider (B) -> 7. VoD (C) -> 10. HDTV (D) -> 13. Setup IPTV account (E) -> 16. Done. A 'Failed, reject application' box is connected to steps 1, 4, 7, 10, and 13. Below the main flow are five external services: 1. Bank credit centre (a) connected to step 1 via '2 Credit check' and '3 OK'. 2. WS registry (b) connected to step 4 via '5 Search IPTV service' and '6 Other term'. 3. A's IPTV solution (c) connected to step 7 via '8 Add new customer' and '9 OK'. 4. B's IPTV solution (d) connected to step 10 via '11 Add new customer' and '12 OK'. 5. Bank accounting service (e) connected to step 13 via '14 Setup auto-withdraw' and '15 OK'. A 'Vendor VoD' box is connected to step 7 via 'Add user'. + +Y.2234(08)\_FI-5 + +**Figure I.5 – IPTV use case** + +A process used to invoke this service could be as follows: + +- 1) A new customer contacts the telco IPTV customer service department to apply for a new IPTV service which includes VoD and HDTV. +- 2) The credit check process contacts the bank credit centre to see if this customer has a good credit standing. +- 3) The credit centre checks its own management database to search for the customer credit data and returns the result of the customer credit check. +- 4) The telco service continues to the next step in the business process when the return status is OK; otherwise, it goes to "Failed, reject application". +- 5) The telco service searches for available VoD and HDTV services. +- 6) The service registry returns a couple of entries – Vendor VoD and company B's HDTV solutions. +- 7) The telco service continues to the next step in the business process when the return status is OK; otherwise, it goes to "Failed, reject application". +- 8) The telco service contacts company A's IPTV service provider to add the new customer and to enable the new service for this customer. +- 9) Company A's IPTV service creates new instances of IPTV customer and services, stores the information in its local management database and returns OK to the telco service. +- 10) The telco service continues to the next step in the business process when the return status is OK; otherwise, it goes to "Failed, reject application". +- 11) The telco service contacts company B, who provides IPTV services, to add a new customer and to enable the new service for this customer. +- 12) Company B's IPTV service creates a new instance of IPTV customer and services, stores the information in its local management database and returns OK to the telco service. +- 13) The telco service continues to the next step in the business process when the return status is OK; otherwise, it goes to "Failed, reject application". +- 14) The telco service contacts the bank accounting service to set-up an auto-withdraw/auto-deposit entry. +- 15) The bank providing the accounting service creates a new entry for this customer and returns OK to the telco service. +- 16) The telco service creates a new entry with a unique customer ID and charging information, and stores necessary vendor-specific customer information in its own local database, including company A's/company B's customer ID and the bank accounting service customer ID/account/transaction requisition number. The new customer set-up for this service is now complete. + +The underlying services and the selection of the underlying services are likely to change from time to time. It is imperative that the customer does not become aware of these underlying changes and, when services are properly implemented, these changes are recommended to be transparent from a customer's perspective. + +Below are two examples: + +- 1) A new service provider publishes the availability of a less expensive or a better service using the OSE service registration capability. The telco service is aware of such a new service deployment via a registry search based on the use of the OSE service discovery capability to obtain the new service. +- 2) A customer would like to choose a different package (i.e., network VoD) via the same telco service provider. The telco service will need to search a fitting service provider and set-up the new service and, in the meantime, will substitute the existing services associated with the underlying services based on the OSE service composition capability. + +# Appendix II + +## Relationship of SOA concepts with open service environment capabilities + +(This appendix does not form an integral part of this Recommendation) + +Service orientated architecture (SOA) is a software architecture concept that uses loosely coupled software services to support the requirements of business processes and software users. Resources on a network in an SOA environment are made available as independent services that can be accessed without the knowledge of their underlying platform implementation. + +The definition of SOA, as in [b-OASIS SOA-RM], reads as follow: "a paradigm for organizing and utilizing distributed capabilities that may be under the control of different ownership domains. It provides a uniform means to offer, discover, interact with and use capabilities to produce desired effects consistent with measurable preconditions and expectations". + +Another definition [b-Newcommer] of SOA is a style of software design that guides all aspects of creating and using business services. SOA is also a way to define and provision an IT infrastructure to allow different applications to exchange data and participate in business processes, regardless of the operating systems or programming language underlying those applications. + +In line with the SOA paradigm, OSE requires the use of standardized interfaces to make NGN capabilities accessible and easy to be used by NGN application providers and developers. + +In this Recommendation, some terminologies are used in the SOA paradigm, including the following two terms related to service composition: + +**(web) service orchestration:** Service orchestration defines the sequence and conditions in which one (web) service invokes other (web) services in order to realize some useful function, i.e., an orchestration is the pattern of interactions that a (web) service agent must follow in order to achieve its goal [b-W3C Glossary]. + +**service choreography:** Service choreography defines the sequence and conditions under which multiple cooperating independent agents exchange messages in order to perform a task to achieve a goal state [b-W3C Glossary]. + +# **Appendix III** + +## **Relationship of standards in other SDOs with open service environment capabilities** + +(This appendix does not form an integral part of this Recommendation) + +This appendix is intended to identify standards in other SDOs that are related to open service environment capabilities. + +### **III.1 Open Service Access (OSA)/Parlay** + +OSA/Parlay standards include the basic framework and standard APIs for network capabilities [b-ETSI ES 203 915-3]. + +Parlay X web service APIs provide a more granular specification than Parlay/OSA APIs. They represent an abstraction and simplification of the Parlay/OSA APIs. Therefore a Parlay X application can be written in any language as long as it can make the proper web service invocations. There are several development tools, for different programming languages, to create, deploy and interact with web services. Parlay X web service APIs may be provided by a Parlay web services gateway which is an intermediary function between the Parlay application server and the Parlay/OSA gateway. However, Parlay X specifications do not mandate a particular implementation approach or architecture and may be used to provide access to service enablers and components through simple abstracted web service APIs. + +OSA/Parlay [b-ETSI ES 203 915-3] information related to OSE capabilities is in clause III.7. + +### **III.2 Open Mobile Alliance (OMA)** + +The OMA is the focal point for the development of mobile service enabler specifications, which support the creation of interoperable end-to-end mobile services. OMA drives service enabler architectures and open enabler interfaces that are independent of the underlying wireless networks and platforms. OMA creates interoperable mobile data service enablers that work across devices, service providers, operators, networks and geographies [b-OMA]. + +OMA specifies an OMA service environment, which is a flexible and extensible architecture that offers support to a diverse group of application developers and service providers. Enablers of OMA service environments provide standardized components to create an environment in which services may be developed and deployed. + +OMA service environment [b-OMA OSE] information related to OSE capabilities is in clause III.7. + +### **III.3 Organization for the Advancement of Structured Information Standards (OASIS)** + +OASIS produces web services standards along with standards for security, e-business and standardization efforts in the public sector and for application-specific markets [b-OASIS]. + +OASIS continues to develop and enhance standards for some of the essential underpinnings of web services, such as managing distributed services, implementing service registry and security, and, at a higher level, for implementing business processes. + +OASIS [b-OASIS] information related to OSE capabilities is in clause III.7. + +### III.4 World Wide Web Consortium (W3C) + +![Figure III.1 – The W3C technology stack. A diagram showing the W3C technology stack as a series of layers. The top layer is a table with six columns: Mobile, Voice, Privacy security, Web applications, Web services, and Semantic web. Each column contains a list of technologies. Below this table are several horizontal bars representing foundational layers: Web accessibility / internationalization / device independence / mobile access / quality assurance; XML, namespaces, schemas, XQuery/XPath, XSLT, DOM, XML base, Xpointer, RDF/XML, SPARQL; XML infoset, RDF(S) graph; Web architectural principles; URI/IRI, HTTP; One web; and Internet.](d17aa1fcc3b86503ad1dd0717a6c34c2_img.jpg) + +| Mobile | Voice | Privacy security | Web applications | Web services | Semantic web | +|--------------|----------|------------------|------------------|--------------|--------------| +| XHTML basic | VoiceXML | P3P | XHTML | SOAP | OWL | +| Mobile SVG | SRGS | APPEL | SVG CDF | MTOM | SKOS | +| SMIL mobile | SSML | XML sig | SMIL | WSDL | GRDDL | +| Xforms basic | CCXML | XML enc | Xforms | WS-CDL | RDFa | +| CSS mobile | EMMA | XKMS | CSS XSL | WS-A | POWDER | +| MWI BP | | | WICD | | RIF | + +Web accessibility / internationalization / device independence / mobile access / quality assurance + +XML, namespaces, schemas, XQuery/XPath, XSLT, DOM, XML base, Xpointer, RDF/XML, SPARQL + +XML infoset, RDF(S) graph + +Web architectural principles + +URI/IRI, HTTP + +One web + +Internet + +Figure III.1 – The W3C technology stack. A diagram showing the W3C technology stack as a series of layers. The top layer is a table with six columns: Mobile, Voice, Privacy security, Web applications, Web services, and Semantic web. Each column contains a list of technologies. Below this table are several horizontal bars representing foundational layers: Web accessibility / internationalization / device independence / mobile access / quality assurance; XML, namespaces, schemas, XQuery/XPath, XSLT, DOM, XML base, Xpointer, RDF/XML, SPARQL; XML infoset, RDF(S) graph; Web architectural principles; URI/IRI, HTTP; One web; and Internet. + +Y.2234(08)\_FIII-1 + +**Figure III.1 – The W3C technology stack** + +The World Wide Web Consortium [b-W3C] is the main international standards organization for the worldwide web (abbreviated WWW or W3). Figure III.1 illustrates one view of the web infrastructure, the main focus of W3C. + +W3C is developing the web services choreography description language (WS-CDL) that is targeted for composing interoperable, peer-to-peer collaborations between any types of participant regardless of the supporting platform or programming model used by the implementation of the hosting environment. + +W3C information related to OSE capabilities is in clause III.7. + +### III.5 Object Management Group (OMG) + +OMG SOA-related activities are based on a platform-independent view. Their focus is the extension of the model driven architecture (MDA) approach, including unified modelling language (UML) to ensure complete and consistent service specifications architected to work together to meet business needs. + +These standards cover a wide spectrum of usage, from high-level representations of an organization and its objectives through operational SOA architectures mapping to technology-specific specifications and their implementations. This includes business rules, processes, service specifications as well as the management of systems and assets. + +The architectural assets developed in the SOA-MDA process contribute to the entire solutions, life-cycle including business analysis, solutions architecture, service interfaces, acquisition, implementation, testing, publishing, discovery and usage of services. + +OMG [b-OMG] information related to OSE capabilities is in clause III.7. + +### III.6 TeleManagement Forum (TMF) + +The TeleManagement Forum (TMF) is an international membership organization of communications service providers and suppliers to the communications industry. While operations support systems (OSS) are generally dominated by proprietary and custom technologies, the TMF is focused on standards and frameworks for OSSs. + +The newest stage in OSS architecture work has come with the TMF's NGOSS programme establishing a set of principles that OSS integration is recommended to adopt, along with a set of models that provide standardized approaches. The models include an information model (the Shared Information/Data model, or SID), a process model (the enhanced Telecom Operation Map, or eTOM), an application model (the Telecom Applications Map), an architecture (the Technology Neutral Architecture) and a lifecycle model. The TMF describes NGOSS as an architecture that is: + +- "loosely coupled"; +- distributed; +- component based; + +along with application components upon which a communications service provider business can run. + +The components interact through a common communications vehicle (using an information exchange infrastructure, e.g., EAI, web services, EJB). + +The behaviour can be controlled through the use of process management and/or policy management to orchestrate the functionality provided by the services offered by the components. + +The early focus of the TMF's NGOSS work was on building reference models to support a business stakeholder view on process, information and application interaction. Running in parallel were activities that supported an implementation stakeholder view on interface specifications to provide access to OSS capability (primarily MTNM). The MTNM work evolved into a set of web services providing multi-technology operations system interfaces (MTOSI). Most recently, the OSS, through Java initiative (OSS/J), joined the TMF to provide NGOSS-based BSS/OSS APIs. + +Another relevant initiative within TMF is the service delivery framework (SDF) programme, aiming to define the framework that supports and integrates all functions required for the lifecycle of a service delivered to a customer, across all stakeholders in a service provider environment. + +TMF [b-TMF] information related to OSE capabilities is in clause III.7. + +### III.7 Information sources for OSE capabilities + +| NGN capabilities | OSA/Parlay
[b-ETSI ES 203 915-3] | OMA OSE
[b-OMA OSE] | OASIS [b-OASIS] | W3C [b-W3C] | OMG [b-OMG] | TMF [b-TMF] | +|----------------------|----------------------------------------------------------------|-------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Service coordination | | PEEM (policy evaluation, enforcement and management)
OSPE (OMA service provider environment) | WS-Coordination
WS-Business activity
WS-Atomic transaction | Web services policy – Framework
Web services policy – Attachment
Web services policy namespace
Web services policy XML schema | Current effort:
– UPMS (SOA extension of UML)
– BPDM
Existing standards:
– UML
– EDOC: component architecture
– Enterprise distributed object computing | TMF053 series: NGOSS technology neutral architecture (TNA)
GB921 series: eTOM, business process framework
GB922 series: SID, shared information architecture
NGOSS Contract metamodel (work in progress) | +| Service discovery | Discovery of framework and network service capability features | OWSER (UDDI)
OMA's DPE
OMA's GPM | Universal description, discovery and integration (UDDI)
ebXML registry information model (RIM)
ebXML registry services and protocols (RS) | Web services description language (WSDL) | Current effort:
– UPMS (SOA extension of UML)
– BPDM
Existing standards:
– RAS: Reusable asset specifications
– RAS description: Metamodel for describing and managing reusable assets | | + +| NGN capabilities | OSA/Parlay
[b-ETSI ES 203 915-3] | OMA OSE
[b-OMA OSE] | OASIS [b-OASIS] | W3C [b-W3C] | OMG [b-OMG] | TMF [b-TMF] | +|-------------------------|--------------------------------------------------------------------------|-----------------------------------------|------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Service management | Registering of network service capability features, integrity management | OSPE (OMA service provider environment) | Management using web services (WSDM-MUWS)
Management of web services (WSDM-MOWS)
WS-Notification
WS-Brokered notification | Service modelling language
WS-Eventing | BPRI: Business process runtime interface

Description: Looking at runtime system, monitoring and measuring it, and evaluating these measurements against expectations

RAS: To publish the services | Current effort: Service delivery framework

Description: A framework that supports and integrates all functions required for the lifecycle of a service delivered to customers, across all stakeholders in a service provider environment. SDF unifies under a logical view service design, creation/ composition, deployment, activation, provisioning, sale and campaign management, execution, operations, charging, billing and revenue management, retirement, monitoring and trouble resolution, etc. | + +| NGN capabilities | OSA/Parlay
[b-ETSI ES 203 915-3] | OMA OSE
[b-OMA OSE] | OASIS [b-OASIS] | W3C [b-W3C] | OMG [b-OMG] | TMF [b-TMF] | +|-----------------------------|-------------------------------------|------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------|--------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Service composition | | PEEM (policy evaluation, enforcement and management) | Business process execution language for web services | Web services choreography description language | Current effort:
– UPMS
– BPMN
– BPDM | | +| Service development support | | XDM, OSPE (OMA service provider environment) | | Service modelling language | Current effort:
– UPMS
– BPMN
– BPDM
Existing standards:
– EDOC | TMF053 series:
NGOSS technology neutral architecture (TNA)
GB921 series:
eTOM, business process framework
GB922 series: SID, shared information architecture
GB942 contract guidelines and principles
NGOSS contract metamodel
MTNM/MTOSI, OSS/J (TIP) | +| Service registration | | OSPE (OMA service provider environment) | ebXML registry information model (RIM)
ebXML registry services and protocols (RS)
Universal description, discovery and integration (UDDI) | | Existing Standards:
– RAS
– MOF | | + +| NGN capabilities | OSA/Parlay
[b-ETSI ES 203 915-3] | OMA OSE
[b-OMA OSE] | OASIS [b-OASIS] | W3C [b-W3C] | OMG [b-OMG] | TMF [b-TMF] | +|-------------------------------------------------|---------------------------------------------|------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------|----------------------| +| Interworking with service creation environments | | | | | | | +| Policy enforcement | Policy management SCF | PEEM (policy evaluation, enforcement and management) | Service component architecture (SCA) policy framework
Privacy policy profile of XACML | Web services policy – Framework
Web services policy – Attachment
Web services policy namespace
Web services policy XML Schema
Web services policy – Primer
Web services policy – Guidelines for policy assertion authors | | SID policy framework | +| Security | Authentication, authorization | SEC_CF (security common function) | WS-Security
WS-Security: SOAP message security
WS-Security: Username token profile
WS-Security: SAML token profile
WS-Security: X.509 certificate token profile
WS-Federation | | | | + +# Bibliography + +- [b-ITU-T I.312] Recommendation ITU-T I.312 (1992), *Principles of intelligent network architecture*. +<> +- [b-ETSI ES 203 915-3] ETSI ES 203 915-3 (2005), *Open Service Access (OSA); Application Programming Interface (API); Part 3: Framework (Parlay 5)*. +<> +- [b-Newcommer] Newcommer, E. and Lomow, G. (2004), *Understanding SOA with Web Services*, Addison-Wesley Professional. +- [b-OASIS] OASIS. <> +- [b-OASIS SOA-RM] OASIS SOA-RM (2006), *Reference Model for Service Oriented Architecture 1.0*. +<> +- [b-OMA] Open Mobile Alliance. <> +- [b-OMA OSE] Open Mobile Alliance OSE 1.0.3 (2006), *OMA Service Environment*. +<[http://www.openmobilealliance.org/technical/release\\_program/ose\\_v1\\_0.aspx](http://www.openmobilealliance.org/technical/release_program/ose_v1_0.aspx)> +- [b-OMG] The Object Management Group. <> +- [b-TMF] TeleManagement Forum. <> +- [b-W3C] World Wide Web Consortium. <> +- [b-W3C Glossary] World Wide Web Consortium Working Group Note (2004), *Web Services Glossary*. +<> + + + +# SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|--------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/Y/T-REC-Y.2235-200811-I_PDF-E/21ad58fee90f2be50708ff541d225507_img.jpg b/marked/Y/T-REC-Y.2235-200811-I_PDF-E/21ad58fee90f2be50708ff541d225507_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..91dfee48ff10cc4b349ac44024b60e0b3b018332 --- /dev/null +++ b/marked/Y/T-REC-Y.2235-200811-I_PDF-E/21ad58fee90f2be50708ff541d225507_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:055893f1a69b1338c056e01fb48b52aa15076aa4ee75d0fb1ab1c088f196b727 +size 118047 diff --git a/marked/Y/T-REC-Y.2235-200811-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg b/marked/Y/T-REC-Y.2235-200811-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..b8fbce075234c5e49fd1290a31541734471c10b3 --- /dev/null +++ b/marked/Y/T-REC-Y.2235-200811-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:49d00e1bf449cc4abd19e1ecaaf9cbf39d94bd5c494b6d40f73fa51e6bf177b3 +size 61015 diff --git a/marked/Y/T-REC-Y.2235-200811-I_PDF-E/4ee27dbf5ef12e7b58b0ef0937bc5a5e_img.jpg b/marked/Y/T-REC-Y.2235-200811-I_PDF-E/4ee27dbf5ef12e7b58b0ef0937bc5a5e_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..6764629172eab09a28e214dfe35c0988bd545a2b --- /dev/null +++ b/marked/Y/T-REC-Y.2235-200811-I_PDF-E/4ee27dbf5ef12e7b58b0ef0937bc5a5e_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:ebffcba13c0f34bd3c038e3c617c9b5d120bdfe27000a3af2a45ace7828b9eae +size 42229 diff --git a/marked/Y/T-REC-Y.2235-200811-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg b/marked/Y/T-REC-Y.2235-200811-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..88632c154204f67da91984ae4bc7c6d4bacd146f --- /dev/null +++ b/marked/Y/T-REC-Y.2235-200811-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:4a006e6f541012ec09ec506c707d47fbf22a22469942f80690151a7e0af06316 +size 6792 diff --git a/marked/Y/T-REC-Y.2235-200811-I_PDF-E/853f59c89931a666c07903b31d098277_img.jpg b/marked/Y/T-REC-Y.2235-200811-I_PDF-E/853f59c89931a666c07903b31d098277_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..2100b4b22f3f4cc7d8b9772be3ed2465296f4577 --- /dev/null +++ b/marked/Y/T-REC-Y.2235-200811-I_PDF-E/853f59c89931a666c07903b31d098277_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:f96811ab582248b55bab5177e92fc2b2fdd5272324ea0e91307960a50d6dbe3c +size 52770 diff --git a/marked/Y/T-REC-Y.2235-200811-I_PDF-E/9c6461e1e94afae4dec455e69a2ce152_img.jpg b/marked/Y/T-REC-Y.2235-200811-I_PDF-E/9c6461e1e94afae4dec455e69a2ce152_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..2524564ff3ca175e253b35b08f75a56c90fba49b --- /dev/null +++ b/marked/Y/T-REC-Y.2235-200811-I_PDF-E/9c6461e1e94afae4dec455e69a2ce152_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:b3eca4599a55cff8d476323729653ac3068e5698f8cd3595e02f7f44f1aae119 +size 76628 diff --git a/marked/Y/T-REC-Y.2235-200811-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg b/marked/Y/T-REC-Y.2235-200811-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..7db387376a591bf0df4ccf2aadf08d7283a73ba5 --- /dev/null +++ b/marked/Y/T-REC-Y.2235-200811-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:3868703dbdc930bcaa2f93de2e458057ea321d9f41e434e56493e43768e9abfb +size 30061 diff --git a/marked/Y/T-REC-Y.2235-200811-I_PDF-E/fa859e4e468bfb2710a94527f2c504af_img.jpg b/marked/Y/T-REC-Y.2235-200811-I_PDF-E/fa859e4e468bfb2710a94527f2c504af_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..bb0cee739acb65e3e4fd5c258c8bd21bef22c861 --- /dev/null +++ b/marked/Y/T-REC-Y.2235-200811-I_PDF-E/fa859e4e468bfb2710a94527f2c504af_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:ff8ef9231d93b82c64ea118e77cbfe848193b8619209d9e453f8aab6e742df79 +size 114761 diff --git a/marked/Y/T-REC-Y.2235-200811-I_PDF-E/raw.md b/marked/Y/T-REC-Y.2235-200811-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..548b8780e744737177acf475c6b41131f2b53a17 --- /dev/null +++ b/marked/Y/T-REC-Y.2235-200811-I_PDF-E/raw.md @@ -0,0 +1,719 @@ + + +I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +## Y.2235 + +(11/2008) + +SERIES Y: GLOBAL INFORMATION +INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS +AND NEXT-GENERATION NETWORKS + +Next Generation Networks – Service aspects: Service +capabilities and service architecture + +# --- **Converged web-browsing service scenarios in NGN** + +Recommendation ITU-T Y.2235 + +![ITU logo](84a1d09fb489061482111515543b60dc_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with a red lightning bolt striking it, and the text "ITU" in blue. To the right of the globe, the words "International Telecommunication Union" are written in a smaller, blue, sans-serif font. + +ITU logo + +## ITU-T Y-SERIES RECOMMENDATIONS **GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT- GENERATION NETWORKS** + +## GLOBAL INFORMATION INFRASTRUCTURE + +| | | +|-------------------------------------------|-------------| +| General | Y.100–Y.199 | +| Services, applications and middleware | Y.200–Y.299 | +| Network aspects | Y.300–Y.399 | +| Interfaces and protocols | Y.400–Y.499 | +| Numbering, addressing and naming | Y.500–Y.599 | +| Operation, administration and maintenance | Y.600–Y.699 | +| Security | Y.700–Y.799 | +| Performances | Y.800–Y.899 | + +## INTERNET PROTOCOL ASPECTS + +| | | +|--------------------------------------------------------------------|---------------| +| General | Y.1000–Y.1099 | +| Services and applications | Y.1100–Y.1199 | +| Architecture, access, network capabilities and resource management | Y.1200–Y.1299 | +| Transport | Y.1300–Y.1399 | +| Interworking | Y.1400–Y.1499 | +| Quality of service and network performance | Y.1500–Y.1599 | +| Signalling | Y.1600–Y.1699 | +| Operation, administration and maintenance | Y.1700–Y.1799 | +| Charging | Y.1800–Y.1899 | + +## NEXT GENERATION NETWORKS + +| | | +|-----------------------------------------------------------------------|----------------------| +| Frameworks and functional architecture models | Y.2000–Y.2099 | +| Quality of Service and performance | Y.2100–Y.2199 | +| Service aspects: Service capabilities and service architecture | Y.2200–Y.2249 | +| Service aspects: Interoperability of services and networks in NGN | Y.2250–Y.2299 | +| Numbering, naming and addressing | Y.2300–Y.2399 | +| Network management | Y.2400–Y.2499 | +| Network control architectures and protocols | Y.2500–Y.2599 | +| Security | Y.2700–Y.2799 | +| Generalized mobility | Y.2800–Y.2899 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +## **Recommendation ITU-T Y.2235** + +# **Converged web-browsing service scenarios in NGN** + +## **Summary** + +Recommendation ITU-T Y.2235 describes converged web-browsing (CWB) capabilities for NGN. CWB capabilities are based on web-based application support built on NGN release 1 (see Recommendation ITU-T Y.2201), with the aim to provide users with a consistent web environment which spans multiple network environments and multiple devices (PC, laptop, PDA, cell phone, etc.). + +CWB provides advanced web-browsing capabilities in different NGN devices and various network environments, including profile-based content adaptation capabilities. The CWB capabilities enable client device (e.g., web browser) of NGN to browse web content effectively, regardless of device and network types. + +This Recommendation identifies web-browsing capability requirements, provides a functional model and service scenarios making use of converged web-browsing capabilities. + +## **Source** + +Recommendation ITU-T Y.2235 was approved on 13 November 2008 by ITU-T Study Group 13 (2009-2012) under Recommendation ITU-T A.8 procedure. + +## **Keywords** + +Converged web-browsing (CWB), NGN, web-browsing. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2009 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## CONTENTS + +| | Page | +|----------------------------------------------------------------------------------|-------------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 2 | +| 4 Abbreviations..... | 2 | +| 5 Conventions ..... | 3 | +| 6 Requirements for converged web-browsing capabilities..... | 3 | +| 7 Functional model for converged web-browsing ..... | 3 | +| 7.1 Functional components..... | 4 | +| 7.2 Operation ..... | 6 | +| 8 Service scenarios using converged web-browsing capabilities in NGN ..... | 7 | +| 8.1 Basic scenario: Web-browsing capabilities without content adaptation ..... | 7 | +| 8.2 Extended scenario: Web-browsing capabilities with content adaptation ..... | 8 | +| 9 Security consideration ..... | 10 | +| Appendix I..... | 11 | +| I.1 CWB positioning within the NGN architecture..... | 11 | +| I.2 Relationship between the web proxy function and NGN functional entities..... | 11 | +| Bibliography..... | 14 | + +## **Introduction** + +In NGN environments, web-based applications allow enhanced utilization of device capabilities and network characteristics [ITU-T Y.2201]. Web-browsing is one of the most popular web-based applications, and it is likely to be widely used in NGN environments. + +In NGN environments, however, traditional web-browsing capabilities may indeed cause failure of a user's device, due to different types of devices (e.g., different screen size or resolution, etc.) and networks (e.g., roaming to different access network: CDMA, WLAN, WiMAX, Bluetooth, etc.). + +To support the web-browsing capabilities in NGN environments, it is required to provide profile based web-browsing capabilities with content adaptation. + +Converged web-browsing (CWB) capabilities enhance the web-browsing experience in terms of supporting different devices (e.g., mobile phone, smart phone, ultra mobile PC, laptop, etc.) and various access networks in NGN. + +## Recommendation ITU-T Y.2235 + +# Converged web-browsing service scenarios in NGN + +# 1 Scope + +The objective of this Recommendation is to describe converged web-browsing capabilities that transform the content according to the different device types of NGN terminals and various network environments supporting web-browsing capabilities. The web-browsing model and service scenarios, using such converged web-browsing capabilities, are also given. + +The scope of this Recommendation is targeted at the converged web-browsing capabilities in NGN with its model and service scenarios. This Recommendation covers: + +- Requirements to support converged web-browsing capabilities; +- Converged web-browsing functional model; +- Converged web-browsing service scenarios. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- [ITU-T Y.2012] Recommendation ITU-T Y.2012 (2006), *Functional requirements and architecture of the NGN release 1*. +- [ITU-T Y.2201] Recommendation ITU-T Y.2201 (2007), *NGN release 1 requirements*. +- [ITU-T Y.2701] Recommendation ITU-T Y.2701 (2007), *Security requirements for NGN release 1*. + +# 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 content transformation function:** A function that has capabilities to perform restructuring, recording and optimizing content. [b-W3C CTG 1.0]. + +NOTE – Content transformation function is used for providing content adaptation capabilities in this Recommendation. + +**3.1.2 proxy:** A software that receives HTTP requests and forwards that request toward an origin server (possibly by way of an upstream proxy) using HTTP. A proxy receives the response from the origin server and forwards it to the requesting client. [b-W3C CC/PP structure and Vocabularies 2.0]. + +**3.1.3 user agent:** A client within a device that performs rendering. Browsers are examples of user agents. [b-W3C GTDI]. + +### 3.2 Terms defined in this Recommendation + +This Recommendation defines the following terms: + +**3.2.1 content adaptation:** Content adaptation is an action of transforming the content to adapt to device capabilities and is done by content transformation function as well as profile serving function. + +NOTE – For example, content adaptation can be applied to mobile devices that require special handling because of their limited computational power, small screen size and constrained keyboard functionality, etc. + +**3.2.2 converged web-browsing capabilities:** Web browsing capabilities that dynamically adapt web content to various terminal devices and network according to profile information, by using content adaptation in the NGN environment. + +**3.2.3 dynamic profile attribute:** A profile attribute that may change its value, e.g., as a result of hardware, software or configuration changes. Examples are the changing of location, battery life, network status (e.g., roaming) and user-defined screen size, etc. + +NOTE – Dynamic profile attribute is not limited to the specific attribute. In other words, any kind of attribute could be a dynamic profile attribute. + +**3.2.4 static profile attribute:** A profile attribute for a device that does not change its value. Examples are supported media types and protocols, screen details (size in pixels, colour resolution, response time, etc.) [ITU-T Y.2201]. In most cases, the static profile attribute is stored in the profile server. + +**3.2.5 web browsing function:** A software application which enables a user to display and interact with text, images, videos, music and other information typically located on a web page at a website on the world wide web or a local area network. + +**3.2.6 web content:** A web content is the textual, visual or aural content that is encountered as part of the user experiences on websites. It may include, among other things: text, images, sounds, videos and animations. + +**3.2.7 web proxy function:** An intermediary function between a web browsing function and a web serving function, which performs protocol conversion, encoding/decoding/caching of content and brokering the HTTP requests (inserting or modifying the profile information into the HTTP request message) on behalf of the web browsing function. + +NOTE – The most common use of a web proxy function is to serve as a web cache. In this Recommendation, the meaning of web proxy function is extended. + +**3.2.8 web serving function:** A function that is responsible for accepting HTTP requests from a web browsing function and serving them HTTP responses along with optional data content, which usually are web pages such as HTML documents and linked objects (images, etc.). + +# 4 Abbreviations + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|--------|---------------------------------------------| +| CDMA | Code Division Multiple Access | +| CWB | Converged Web-Browsing | +| GSC-FE | General Services Control Functional Entity | +| HTML | HyperText Markup Language | +| HTTP | HyperText Transfer Protocol | +| MRC-FE | Media Resource Control Functional Entity | +| MRP-FE | Media Resource Processing Functional Entity | + +| | | +|--------|-------------------------------------------------| +| NGN | Next Generation Network | +| PDA | Personal Digital Assistant | +| SUP-FE | Service User Profile Functional Entity | +| TUP-FE | Transport User Profile Functional Entity | +| URI | Uniform Resource Identifier | +| W3C | World Wide Web Consortium | +| WiMAX | Worldwide Interoperability for Microwave Access | +| WLAN | Wireless Local Area Network | + +# 5 Conventions + +None. + +# 6 Requirements for converged web-browsing capabilities + +This clause describes the requirements of converged web-browsing capabilities for NGN. The converged web-browsing capabilities are required to: + +- Provide 'web-based application support' satisfying with interoperability across wired and wireless network environment [ITU-T Y.2201] +- Provide the profile serving function which stores the user profile and device profile information +- Provide profile processing to support content adaptation: + - Request and respond with the profile information to the profile serving function + - Update the profile information + - Adapt the profile information (inserting and modifying the profile) +- Provide content processing to support content transformation: + - Transform the content according to profile information + - Deliver the transformed content to requester (e.g., web proxy function) +- Provide the delivering of profile information by terminal: + - Send the profile information through HTTP request messages by the web browsing function (e.g., when the profile attribute is changed) +- Provide the service registration function for the terminal: + - Registration and de-registration of the web browsing function to the web proxy function + +# 7 Functional model for converged web-browsing + +This clause describes the functional model for CWB capabilities in NGN, including the functional components and operations. The roles of service components are specified in terms of profile delivery as well as content adaptation. + +Figure 1 shows the functional model for CWB capabilities. This model consists of five components: a web browsing function, a web proxy function, a web serving function, a profile serving function and a content transformation function. + +![Functional model for converged web-browsing capabilities diagram](a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg) + +``` + +graph TD + WBF((Web browsing +function)) --- IBP(.) --- WPF((Web proxy +function)) + WPF --- IPS(.) --- WSF((Web serving +function)) + WPF --- IPP(.) --- PSF((Profile +serving +function)) + WPF --- IPT(.) --- CTF((Content +trans- +formation +function)) + + style IBP fill:none,stroke:none + style IPS fill:none,stroke:none + style IPP fill:none,stroke:none + style IPT fill:none,stroke:none + +``` + +The diagram illustrates a functional model with five circular nodes. At the top level, from left to right, are 'Web browsing function', 'Web proxy function', and 'Web serving function'. Below the 'Web proxy function' are two more nodes: 'Profile serving function' (left) and 'Content transformation function' (right). Lines connect the 'Web proxy function' to all other four nodes. Each connection line is bisected by a short perpendicular tick mark with a label: $I_{BP}$ between browsing and proxy, $I_{PS}$ between proxy and serving, $I_{PP}$ between proxy and profile serving, and $I_{PT}$ between proxy and content transformation. The reference 'Y.2235(08)\_F01' is in the bottom right. + +Functional model for converged web-browsing capabilities diagram + +**Figure 1 – Functional model for converged web-browsing capabilities** + +In CWB model, four kinds of behaviours must take place: interaction between a web browsing function and a web proxy function, interaction between a web proxy function and a web serving function, interaction between a web proxy function and a profile serving function, and interaction between a web proxy function and a content transformation function. In detail, these operations are as follows: + +$I_{BP}$ Service request with profile information and response of content + +$I_{PS}$ Service request on behalf of a web browsing function with profile information and response of content + +$I_{PP}$ Profile request and response + +$I_{PT}$ Transformation request and response of content + +NOTE – It is assumed that a web browsing function must interact through the web proxy function. In other words, the web browsing function cannot directly interact with the web serving function. + +### **7.1 Functional components** + +#### **7.1.1 Web browsing function** + +A web browsing function allows a user to access information provided on web pages at websites by traversing hyperlinks. The web browser function is able to insert profile information into an HTTP request message as an option when initiating a request for accessing a content of a web browsing serving function. + +The web browsing functions include the following, but are not limited to: + +- Request the web content with URI; +- Navigate and display the received web content; +- Request to register and de-register for service subscription to a web proxy function; +- Insert the profile information into an HTTP request message and send it when some profile attribute has been changed (dynamic profile attribute). + +#### **7.1.2 Web serving function** + +A web serving function is responsible for providing content requested by a web proxy function or a web browsing function. In some cases, the web serving function may have a capability to transform content into an appropriate form according to the profile information. If the web serving function has no capability to perform content adaptation capability, the web proxy function can take the role of content transformation. + +The web serving functions include the following, but are not limited to: + +- Provide the web content requested by a web proxy function or a web browsing function; + +- Transform the web content according to the profile information (if a web serving function has a capability to perform the content transformation). + +#### 7.1.3 Web proxy function + +A web proxy function is an intermediary function located between a web browsing function and a web serving function. Basically, a web proxy function receives the request message from a web browsing function and requests the appropriate profile from a profile serving function. Then the web proxy function requests the web content from the web serving function and receives the web content. In doing so, the web proxy function performs the profile processing and the content processing according to the profile information. + +For the profile processing, the web proxy function does insert the profile information into the HTTP request message and sends it to the web serving function. Also, when the profile information of the web browsing function has been changed dynamically, the web proxy function delivers the changed profile to the web serving function by using an HTTP request message. In this case, the web browsing function informs the web proxy function of the change of profile information through the HTTP request message from the web browsing function. + +For the content processing, if the web serving function does not perform content adaptation, the web proxy function does transform the content from the web serving function by using the content transformation function. In this case, the web proxy function requests to transform the web content to the content transformation function. If the web serving function does perform the content adaptation, the web proxy function simply bypasses the web content to the web browsing function as it is. + +The web proxy functions include the following, but are not limited to: + +- Register and de-register the web browsing function for service subscription; +- Forward the web content to the web browsing function from the web serving function or the content transformation function; +- Retrieve the profile information from the profile serving function; +- Update the profile information in the profile serving function; +- Request to transform the web content to the content transformation function (in case the web serving function does not perform content adaptation); +- Determine whether the profile processing and/or content processing is necessary or not according to profile information; +- Insert or modify profile information when sending an HTTP request message to the web serving function. + +#### 7.1.4 Profile serving function + +The profile serving function is storing the profile information about the user and the device. It responds with the profile information to the request from a web proxy function. A user profile is a set of stored information related to authentication, authorization, mobility, location, charging, etc. A device profile is a set of stored information related to the terminal (e.g., screen size, supported media, etc.). + +The profile serving functions include the following, but are not limited to: + +- Store, retrieve and update a profile information about user and device profile; +- Deliver the profile information to the web proxy function. + +NOTE – TUP-FE and SUP-FE in NGN [ITU-T Y.2012] could be used as a profile serving function. + +#### 7.1.5 Content transformation function + +The content transformation function has the capabilities to transform the web content into an appropriate form according to the profile information. It is under the control of a web proxy function. + +The content transformation functions include the following, but are not limited to: + +- Transform the web content according to profile information; + - Types of transformation are restructuring, recording, and optimizing. [b-W3C CTG 1.0] +- Deliver the transformed content to the web proxy function. + +NOTE – MRC-FE in NGN [ITU-T Y.2012] could be used as a part of a content transformation function. + +### 7.2 Operation + +The basic operation of CWB is shown in Figure 2. The operations are associated with all functional components described in clause 7.1. Regarding the operational aspects, the web proxy function has two capabilities, which are profile processing and content processing. + +![Figure 2: Operations for converged web-browsing capabilities. The diagram shows a central 'Web proxy function' box containing 'Profile processing' and 'Content processing' ovals. It is connected to four external functions: 'Profile serving function' (top), 'Web browsing function' (left), 'Web serving function' (right), and 'Content transformation function' (bottom). Data flows are labeled with identifiers and profiles (I_PP, I_BP, I_PS) and content (I_PT, I_PT(content, profile)).](853f59c89931a666c07903b31d098277_img.jpg) + +``` + +graph TD + PSF[Profile serving function] + WBF[Web browsing function] + WPF[Web proxy function] + WSF[Web serving function] + CTF[Content transformation function] + + WPF -- "I_PP (identifier, profile)" --> PSF + PSF -- "I_PP (identifier, profile)" --> WPF + WBF -- "I_BP (URI, profile)" --> WPF + WPF -- "I_BP (content)" --> WBF + WPF -- "I_PS (URI, profile)" --> WSF + WSF -- "I_PS (content)" --> WPF + CTF -- "I_PT (content)" --> WPF + WPF -- "I_PT (content, profile)" --> CTF + + subgraph WPF_Box [Web proxy function] + PP([Profile processing]) + CP([Content processing]) + end + +``` + +Figure 2: Operations for converged web-browsing capabilities. The diagram shows a central 'Web proxy function' box containing 'Profile processing' and 'Content processing' ovals. It is connected to four external functions: 'Profile serving function' (top), 'Web browsing function' (left), 'Web serving function' (right), and 'Content transformation function' (bottom). Data flows are labeled with identifiers and profiles (I\_PP, I\_BP, I\_PS) and content (I\_PT, I\_PT(content, profile)). + +Y.2235(08)\_F02 + +**Figure 2 – Operations for converged web-browsing capabilities** + +#### 7.2.1 Operation details + +The details for each operation are the following: + +- | | | +|--------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| $I_{BP}(\text{URI, profile})$ | The web browsing function sends a browsing request with URI to the web proxy function. In case that some profile information has been changed in the terminal, the profile information is also being delivered to the web proxy function. | +| $I_{BP}(\text{content})$ | The web proxy function responds with the content to the web browsing function. | +| $I_{PP}(\text{identifier, profile})$ |

(1) The web proxy function requests the profile from the profile serving function with identifier of a user or a browsing function (from web proxy function to profile serving function).

(2) The profile serving function responds with the profile for identifier (From profile serving function to web proxy function).

| +| $I_{PS}(\text{URI, profile})$ | The web proxy function requests the content from a web serving function. | +| $I_{PS}(\text{content})$ | The web serving function responds with the content to a web proxy function. | + +| | | +|-----------------------------------|-----------------------------------------------------------------------------------------------------------------------------------| +| $I_{PT}(\text{content, profile})$ | The web proxy function requests to transform the content from a content transformation function according to profile information. | +| $I_{PT}(\text{content})$ | The content transformation function responds with the transformed content to a web proxy function. | + +#### 7.2.2 Profile processing + +Profile processing is responsible for the management of profile at the web proxy function. The sequences of profile processing are as follows: + +- Examine the profile information of HTTP request message from a web browsing function. +- If a message does not contain the profile information, do request the profile information from a profile serving function. +- If a message does contain the profile information (e.g., due to dynamic profile attribute), do update the profile information to a profile serving function with received profile from a web browsing function. +- Send the HTTP request message with URI and profile information to the web serving function. + +#### 7.2.3 Content processing + +Content processing is responsible for transforming the web content according to the appropriate profile information at the web proxy function. The sequences of content processing are as follows: + +- After receiving the web content from a web serving function, do determine whether the content adaptation is necessary or not. +- If content adaptation is required, do request to transform the received content from the content transformation function. +- If content adaptation is not required, do deliver the received content to the web browsing function as it is. + +# 8 Service scenarios using converged web-browsing capabilities in NGN + +The NGN devices tend to be heterogeneous with highly variable capabilities. A web browsing function is also optimized for certain content format, and it has a growing number of configurations, versions, and releases. Also it may be difficult for the web serving function to take into account a large number of different devices. Therefore, the profile inconsistency can occur between the web browsing functions and the web serving functions. Specifically, mobile devices may receive the web content which could not be stored or displayed. Since device capabilities and network conditions can change dynamically, the web browsing capabilities need to be able to respond to these changes accordingly. + +Therefore, content adaptation is required based on the profile attribute. The web proxy function can be introduced to enable content adaptation between the web browsing function and the web serving function in NGN. + +This clause describes two scenarios that are distinguished according to whether content adaptation is required or not. + +### 8.1 Basic scenario: Web-browsing capabilities without content adaptation + +In this scenario, a web browsing function is serviced through the web proxy function without any content adaptation. The web browsing function requests the web content with URI through HTTP request message from the web proxy function, and the web proxy function gets the browser's profile from the profile serving function and then receives the best suited web content from the web serving function. In this case, it is assumed that the web serving function and the web browsing function + +have matching profile, and the web serving function has the capabilities to support suitable content for the profile information. Given that content adaptation is not required, the web proxy function simply forwards the content to the web browsing function. + +NOTE – Figure 3 shows an example of the information flows for basic web-browsing capabilities without content adaptation. + +![Sequence diagram showing information flow between NGN terminal (Web browsing function), Web proxy function, Profile serving function, and Web serving function.](4ee27dbf5ef12e7b58b0ef0937bc5a5e_img.jpg) + +``` + +sequenceDiagram + participant WB as Web browsing function + participant WP as Web proxy function + participant PS as Profile serving function + participant WS as Web serving function + + Note over WB: NGN terminal + WB->>WP: (1) IBP(URI) + WP->>PS: (2) IPP (identifier) + PS-->>WP: (3) IPP (identifier, profile) + WP->>WS: (4) IPS (URI, profile) + WS-->>WP: (5) IPS (contents) + WP-->>WB: (6) IBP (contents) + +``` + +Y.2235(08)\_F03 + +Sequence diagram showing information flow between NGN terminal (Web browsing function), Web proxy function, Profile serving function, and Web serving function. + +- (1) The web browsing function requests the web content with URI through an HTTP request message from the web proxy function. +- (2) The web proxy function requests profile from the profile serving function. +- (3) The profile serving function responds with the profile. +- (4) The web proxy function requests the web content from the web serving function with profile. +- (5) The web serving function responds with the requested web content to the web proxy function. +- (6) The web proxy function transmits the web content to the web browsing function as it is. + +**Figure 3 – An example of information flow of web-browsing capabilities +without content adaptation** + +### 8.2 Extended scenario: Web-browsing capabilities with content adaptation + +#### 8.2.1 Content adaptation with static profile attribute + +When the web proxy function receives the web content from the web serving function, the web proxy function does compare the profile information to the received web content, and then determines whether content adaptation is necessary or not. If there is profile inconsistency with the web serving function, the web proxy function requests content transformation from the content transformation function. When the web proxy function receives the appropriate content from the content transformation function, the web proxy function delivers it to the web browsing function. + +NOTE – Figure 4 shows an example of the information flows describing how the web-browsing function can be served by the web serving function through the web proxy function according to the static profile. + +![Sequence diagram showing information flow for static profile-based content adaptation between NGN terminal components.](33ed1f9b27c7c21c797aa928b0f06851_img.jpg) + +The diagram illustrates the information flow for static profile-based content adaptation between five components: Web browsing function, Web proxy function, Content transformation function, Profile serving function, and Web serving function. The flow is as follows: + +- (1) $I_{BP}(\text{URI})$ : Web browsing function to Web proxy function. +- (2) $I_{pp}(\text{identifier})$ : Web proxy function to Profile serving function. +- (3) $I_{pp}(\text{identifier, profile})$ : Profile serving function to Web proxy function. +- (4) $I_{PS}(\text{URI, profile})$ : Web proxy function to Web serving function. +- (5) $I_{PS}(\text{contents})$ : Web serving function to Web proxy function. +- (6) $I_{PT}(\text{contents, profile})$ : Web proxy function to Content transformation function. +- (7) $I_{PT}(\text{adapted contents})$ : Content transformation function to Web proxy function. This step is part of a "Content adaptation" process. +- (8) $I_{BP}(\text{adapted contents})$ : Web proxy function to Web browsing function. + +Y.2235(08)\_F04 + +Sequence diagram showing information flow for static profile-based content adaptation between NGN terminal components. + +- (1) The web browsing function requests the web content with URI through an HTTP request message from the web proxy function. +- (2) The web proxy function requests profile from the profile serving function. +- (3) The profile serving function responds with the profile. +- (4) The web proxy function requests the web content from the web serving function with profile. +- (5) The web serving function responds with the requested web content to the web proxy function. +- (6) If the profile attribute between the web browsing function and the web serving function does not match, the web proxy function requests to transform the web content from the content transformation function. +- (7) The content transformation function transforms the received web content into an appropriate form to enable the web browsing function to perceive it well, and then transmits it to the web proxy function. +- (8) The web proxy function transmits the adapted web content to the web browsing function. + +**Figure 4 – An example of information flow of static profile-based content adaptation** + +#### 8.2.2 Content adaptation with dynamic profile attribute + +When the profile information of the terminal has been changed due to some reason, i.e., changing of network status, location, user preferences and other factors affecting it, the web browsing function informs the web proxy function of these changes through the HTTP request message with changed profile. The web proxy function executes profile processing and content processing, as described in clauses 7.2.2 and 7.2.3. + +NOTE – Figure 5 shows an example of information flow describing how the web browsing function should be served by the web serving function through the web proxy function according to the dynamically changing profile. + +![Sequence diagram showing information flow for dynamic profile-based content adaptation between NGN terminal components: Web browsing function, Web proxy function, Content transformation function, Profile serving function, and Web serving function. The diagram illustrates two scenarios: a standard request and a profile update scenario. In the first scenario, the Web browsing function sends a request (1) to the Web proxy function, which then requests a profile (2) from the Profile serving function. The Profile serving function responds with the profile (3), and the Web proxy function requests content (4) from the Web serving function. The Web serving function transmits the content (5) to the Web proxy function, which then requests transformation (6) from the Content transformation function. The Content transformation function returns adapted content (7), which is then sent to the Web browsing function (8). In the second scenario, the Web browsing function informs the Web proxy function of a profile change (9). The Web proxy function requests an updated profile (10) from the Profile serving function, which responds (11). The Web proxy function then requests content (12) from the Web serving function, which transmits it (13). The Web proxy function requests transformation (14) from the Content transformation function, which returns adapted content (15), which is then sent to the Web browsing function (16). A green starburst labeled 'Profile attribute changed' is next to message (9).](fa859e4e468bfb2710a94527f2c504af_img.jpg) + +``` + +sequenceDiagram + participant WBF as Web browsing function + participant WPF as Web proxy function + participant CTF as Content transformation function + participant PSF as Profile serving function + participant WSF as Web serving function + + WBF->>WPF: (1) IBP(URI) + WPF->>PSF: (2) Ipp (identifier) + PSF-->>WPF: (3) Ipp (identifier, profile) + WPF->>WSF: (4) Ips (URI, profile) + WSF-->>WPF: (5) Ips (contents) + WPF->>CTF: (6) IPT (contents, profile) + CTF-->>WPF: (7) IPT (adapted contents) + WPF-->>WBF: (8) IBP (adapted contents) + WBF-->>WPF: (9) IBP (URI, changed profile) + WPF->>PSF: (10) Ipp (identifier, changed profile) + PSF-->>WPF: (11) Ipp (identifier) + WPF->>WSF: (12) Ips (URI, changed profile) + WSF-->>WPF: (13) Ips (contents) + WPF->>CTF: (14) IPT (contents, profile) + CTF-->>WPF: (15) IPT (adapted contents) + WPF-->>WBF: (16) IBP (adapted contents) + +``` + +Y.2235(08)\_F05 + +Sequence diagram showing information flow for dynamic profile-based content adaptation between NGN terminal components: Web browsing function, Web proxy function, Content transformation function, Profile serving function, and Web serving function. The diagram illustrates two scenarios: a standard request and a profile update scenario. In the first scenario, the Web browsing function sends a request (1) to the Web proxy function, which then requests a profile (2) from the Profile serving function. The Profile serving function responds with the profile (3), and the Web proxy function requests content (4) from the Web serving function. The Web serving function transmits the content (5) to the Web proxy function, which then requests transformation (6) from the Content transformation function. The Content transformation function returns adapted content (7), which is then sent to the Web browsing function (8). In the second scenario, the Web browsing function informs the Web proxy function of a profile change (9). The Web proxy function requests an updated profile (10) from the Profile serving function, which responds (11). The Web proxy function then requests content (12) from the Web serving function, which transmits it (13). The Web proxy function requests transformation (14) from the Content transformation function, which returns adapted content (15), which is then sent to the Web browsing function (16). A green starburst labeled 'Profile attribute changed' is next to message (9). + +- (1) The web browsing function requests the web content with URI through an HTTP request message from a web proxy function. +- (2) The web proxy function requests the profile from a profile serving function. +- (3) The profile serving function responds with the profile. +- (4) The web proxy function requests the web content from the web serving function with profile. +- (5) The web serving function transmits the requested web content to the web proxy function. +- (6) If the profile attribute between the web browsing function and the web serving function does not match, the web proxy function requests to transform from the content transformation function. +- (7) The content transformation function transforms the received web content into an appropriate form to enable the web browsing function to perceive it well, and then transmits it to the web proxy function. +- (8) The web proxy function transmits the adapted web content. +- (9) If profile attribute has been changed on the web browsing function side, the web browsing function informs the web proxy function about it. +- (10) If the profile needs to be updated, the web proxy function requests the profile serving function to update the profile attribute. +- (11) If the profile serving function receives the updated profile attribute, the profile serving function updates it and sends the response message to the web proxy function. +- (12) The web proxy function requests the web content from the web serving function with changed profile. +- (13) The web serving function transmits the requested web content to the web proxy function. +- (14) If the profile attribute between the web browsing function and the web serving function does not match, the web proxy function requests content transformation from the content transformation function. +- (15) The content transformation function transforms the received web content into an appropriate form to enable the web browsing function to perceive it well, and then transmits it to the web proxy function. +- (16) The web proxy function transmits the adapted web content to the web browsing function. + +**Figure 5 – An example of information flow of dynamic profile-based content adaptation** + +# 9 Security consideration + +This Recommendation does not identify additional NGN security requirements beyond the ones contained in [ITU-T Y.2701]. + +# Appendix I + +(This appendix does not form an integral part of this Recommendation) + +This appendix describes CWB capabilities positioning within the NGN architecture as well as the relationship between the web proxy function and NGN functional entities to show the possibility of applying web-based capabilities in NGN. This appendix will be examined for the future enhancement of the NGN architecture. + +## I.1 CWB positioning within the NGN architecture + +Figure I.1 is an extension of Figure 1 in [ITU-T Y.2012], NGN architecture overview. It shows an extended NGN architecture enabling the support of converged web-browsing capabilities. In particular, the web proxy function is added in the NGN service stratum for profile processing as well as for content processing. + +From the NGN architectural point of view, the web proxy function could be an instance of GSC-FE or a new FE to define for the support of CWB. + +![Figure I.1: Extended NGN architecture positioning the CWB. The diagram shows a multi-layered architecture. At the top is 'Applications' connected to the 'ANI' (Application Network Interface). Below this is the 'Service stratum' (green background), which contains 'Applications support functions and service support functions' at the top, followed by 'Service control functions' in the middle. The 'Service control functions' are flanked by 'Service user profiles' (represented by a cylinder) on the left and the 'Web proxy function' (represented by an orange box) on the right. Below the Service stratum is the 'Transport stratum' (yellow background), which contains 'Transport control functions' in the middle. These are flanked by 'Network attachment control functions' (with 'Transport user profiles' cylinder) on the left and 'Resource and admission control functions' on the right. At the bottom of the Transport stratum is 'Transport functions'. To the left of the main strata is a vertical purple bar labeled 'Management functions'. To the right is a vertical white bar labeled 'Other networks'. On the far left, a vertical white bar contains 'Web browsing function' and 'End-user functions'. On the far right, a vertical white bar contains 'Web serving function'. The architecture is bounded by 'UNI' (User Network Interface) on the left and 'NNI' (Network Network Interface) on the right. Dotted lines represent control planes, hatched lines represent media planes, and green dashed lines represent management planes. A legend at the bottom identifies these line types: dotted for Control, hatched for Media, and green dashed for Management. The reference 'Y.2235(08)_FI-1' is located at the bottom right of the diagram area.](21ad58fee90f2be50708ff541d225507_img.jpg) + +Figure I.1: Extended NGN architecture positioning the CWB. The diagram shows a multi-layered architecture. At the top is 'Applications' connected to the 'ANI' (Application Network Interface). Below this is the 'Service stratum' (green background), which contains 'Applications support functions and service support functions' at the top, followed by 'Service control functions' in the middle. The 'Service control functions' are flanked by 'Service user profiles' (represented by a cylinder) on the left and the 'Web proxy function' (represented by an orange box) on the right. Below the Service stratum is the 'Transport stratum' (yellow background), which contains 'Transport control functions' in the middle. These are flanked by 'Network attachment control functions' (with 'Transport user profiles' cylinder) on the left and 'Resource and admission control functions' on the right. At the bottom of the Transport stratum is 'Transport functions'. To the left of the main strata is a vertical purple bar labeled 'Management functions'. To the right is a vertical white bar labeled 'Other networks'. On the far left, a vertical white bar contains 'Web browsing function' and 'End-user functions'. On the far right, a vertical white bar contains 'Web serving function'. The architecture is bounded by 'UNI' (User Network Interface) on the left and 'NNI' (Network Network Interface) on the right. Dotted lines represent control planes, hatched lines represent media planes, and green dashed lines represent management planes. A legend at the bottom identifies these line types: dotted for Control, hatched for Media, and green dashed for Management. The reference 'Y.2235(08)\_FI-1' is located at the bottom right of the diagram area. + +**Figure I.1 – Extended NGN architecture positioning the CWB** + +NOTE 1 – Other networks may include other types of NGN and many existing networks, such as the PSTN/ISDN, the public Internet, and so forth [ITU-T Y.2201]. + +NOTE 2 – The web serving function may exist in NGN networks as well as in other networks. + +### I.2 Relationship between the web proxy function and NGN functional entities + +In this appendix, the relationship between the web proxy function and NGN functional entities is described and some NGN FEs functionalities are expected to be extended. + +[ITU-T Y.2012] describes the functional architecture of NGN for release 1. It is assumed that the NGN functional entities communicating with the web proxy function may be S-5, S-13, T-8, T-12, T-16, A-1 and A-3 as illustrated in Figure I.2. These functional entities expect to extend their functionalities to support web-browsing capabilities in NGN. From the NGN architectural point of view, web proxy could be an instance of GSC-FE or a new FE for the support of CWB. + +#### 1) *S-5 Service user profile functional entity (SUP-FE)* + +The service user profile functional entity (SUP-FE) is responsible for storing user profiles, subscriber-related location data, and presence status data in the service stratum. SUP-FE provides information such as user preference by request of a web proxy function. + +#### 2) *S-13 Media resource control functional entity (MRC-FE)* + +The MRC-FE allows MRP-FE to transform content that can be recognized by the web browsing function. + +#### 3) *T-8 Media resource processing functional entity (MRP-FE)* + +The MRP-FE provides payload processing of packets used in the NGN. It, especially, provides transcoding and recording capabilities under the control of the MRC-FE. MRP-FE expects to extend its capabilities to content transformation for the support of CWB. + +#### 4) *T-12 Transport user profile functional entity (TUP-FE)* + +The TUP-FE is responsible for storing user profiles (e.g., QoS profile, P-CSC-FE address, and HGWC-FE address) related to the transport stratum. TUP-FE expects to extend its capabilities to store user profile information (e.g., proxy address) related to CWB. + +#### 5) *T-16 Policy decision functional entity (PD-FE)* + +The PD-FE responds to service request from the web proxy function and then manages and controls the policies and resources of the transport stratum for the support of CWB. + +#### 6) *A-1 Application server functional entity (AS-FE)* + +The AS-FE provides value-added information such as user's availability and location to the web proxy function. The web proxy function, therefore, can customize and personalize the content suitable for the user's purpose. + +#### 7) *A-3 Application service coordination manager functional entity (APL-SCM-FE)* + +A web proxy function might interwork with an AS-FE via an APL-SCM to provide convergent services to the end user. + +![Diagram of NGN functional entities interacting with a web proxy function. The diagram is organized into four horizontal layers: Applications support functions and service support functions, Service control functions, Transport control functions, and Transport processing functions. The Web proxy function is highlighted in yellow in the Service control functions layer. It connects to A-1: AS-FE and A-3: APL-SCM-FE in the top layer, S-13: media resource control FE and S-5: service user profile FE in the Service control functions layer, T-12: T. user profile FE (under NACF) and T-16: policy decision FE (under RACF) in the Transport control functions layer, and T-8: media resource processing FE in the Transport processing functions layer. A vertical line connects the top layer to the Transport control functions layer, with a dot indicating a connection point between the Transport control functions and Transport processing functions layers.](9c6461e1e94afae4dec455e69a2ce152_img.jpg) + +The diagram illustrates the functional entities of an NGN network, organized into four main layers: + +- Applications support functions and service support functions:** Contains A-1: AS-FE and A-3: APL-SCM-FE. +- Service control functions:** Contains the **Web proxy function** (highlighted in yellow), S-13: media resource control FE, and S-5: service user profile FE. +- Transport control functions:** Contains NACF (T-12: T. user profile FE) and RACF (T-16: policy decision FE). +- Transport processing functions:** Contains T-8: media resource processing FE. + +Connections are shown as follows: + +- A vertical line connects A-1: AS-FE and A-3: APL-SCM-FE to the Web proxy function. +- The Web proxy function connects to S-13: media resource control FE and S-5: service user profile FE. +- S-13: media resource control FE connects to T-12: T. user profile FE. +- S-5: service user profile FE connects to T-16: policy decision FE. +- T-12: T. user profile FE and T-16: policy decision FE are connected by a horizontal line. +- T-12: T. user profile FE connects to T-8: media resource processing FE. +- T-16: policy decision FE connects to T-8: media resource processing FE. + +Y.2235(08)\_FI-2 + +Diagram of NGN functional entities interacting with a web proxy function. The diagram is organized into four horizontal layers: Applications support functions and service support functions, Service control functions, Transport control functions, and Transport processing functions. The Web proxy function is highlighted in yellow in the Service control functions layer. It connects to A-1: AS-FE and A-3: APL-SCM-FE in the top layer, S-13: media resource control FE and S-5: service user profile FE in the Service control functions layer, T-12: T. user profile FE (under NACF) and T-16: policy decision FE (under RACF) in the Transport control functions layer, and T-8: media resource processing FE in the Transport processing functions layer. A vertical line connects the top layer to the Transport control functions layer, with a dot indicating a connection point between the Transport control functions and Transport processing functions layers. + +**Figure I.2 – Example of NGN functional entities interacting with a web proxy function** + +## Bibliography + +- [b-W3C CC/PP structure and Vocabularies 2.0] W3C, *Composite Capability/Preference Profiles (CC/PP): Structure and Vocabularies 2.0*. + +- [b-W3C GTDI] W3C, *Glossary of Terms for Device Independence*. + +- [b-W3C DDL 1.0] W3C, *Device Description Landscape 1.0: W3C Working Group Note 31*, October 2007. + +- [b-W3C CTG 1.0] W3C, *Content Transformation Guidelines 1.0*. + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|--------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/Y/T-REC-Y.2255-201801-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg b/marked/Y/T-REC-Y.2255-201801-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..34f1ecdd1dd47fc9e7c6d581c9dc9e11f83e7152 --- /dev/null +++ b/marked/Y/T-REC-Y.2255-201801-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:a427b14e8248a27903f73520edd1fefbb9601575be32fcd6485104ca24e7c815 +size 34265 diff --git a/marked/Y/T-REC-Y.2255-201801-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg b/marked/Y/T-REC-Y.2255-201801-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..cd1632d6e9b9ffd97ff41f21ce76121527a06ec4 --- /dev/null +++ b/marked/Y/T-REC-Y.2255-201801-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:b341373fe135c25ba81a7a3f3b76472ad07020ae38ff80e5a3c7561d89e7c50f +size 45044 diff --git a/marked/Y/T-REC-Y.2255-201801-I_PDF-E/5b8a756d9a71c35f17db8bcb90b438a3_img.jpg b/marked/Y/T-REC-Y.2255-201801-I_PDF-E/5b8a756d9a71c35f17db8bcb90b438a3_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..c7d8ba627001618cfca90bdcc4a4e96c4f01e5eb --- /dev/null +++ b/marked/Y/T-REC-Y.2255-201801-I_PDF-E/5b8a756d9a71c35f17db8bcb90b438a3_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:5a53c5d9adcdfdefd8951de99a9786c80722d26b54b1a69a0d5fb85ddfd050b8 +size 79502 diff --git a/marked/Y/T-REC-Y.2255-201801-I_PDF-E/7e670a2b556b53ea9002dfff3a420e08_img.jpg b/marked/Y/T-REC-Y.2255-201801-I_PDF-E/7e670a2b556b53ea9002dfff3a420e08_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..bd77f7f4f6a510303362d96c0dbf7903e9fe198d --- /dev/null +++ b/marked/Y/T-REC-Y.2255-201801-I_PDF-E/7e670a2b556b53ea9002dfff3a420e08_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:95f930616685eee4371c3d857e50ec354fe5b4db9b2dc85726e5b29f16cd9509 +size 27755 diff --git a/marked/Y/T-REC-Y.2255-201801-I_PDF-E/8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg b/marked/Y/T-REC-Y.2255-201801-I_PDF-E/8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..f9079c82110e6b0caef275d3e9a8eaecbfd4b92a --- /dev/null +++ b/marked/Y/T-REC-Y.2255-201801-I_PDF-E/8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:72ad05826136cb1997b20247e86a8f2f00271f6bf8f9b8733e441fa48148071c +size 81565 diff --git a/marked/Y/T-REC-Y.2255-201801-I_PDF-E/a3dc41dc3df86ea68d266af2bf95cf5b_img.jpg b/marked/Y/T-REC-Y.2255-201801-I_PDF-E/a3dc41dc3df86ea68d266af2bf95cf5b_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..072f073b6d42cbfa77c827c76c611f286177034a --- /dev/null +++ b/marked/Y/T-REC-Y.2255-201801-I_PDF-E/a3dc41dc3df86ea68d266af2bf95cf5b_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:ee72ddf991b7b1d543b2694b1687804845ecb97da77cc35e98e4c7dbf5ac163d +size 4142 diff --git a/marked/Y/T-REC-Y.2255-201801-I_PDF-E/a83ba9e3e2c1e21dd69953a7b09e45b4_img.jpg b/marked/Y/T-REC-Y.2255-201801-I_PDF-E/a83ba9e3e2c1e21dd69953a7b09e45b4_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..41ac42a5db521c8481701ec91d9d207aeb9aeb3f --- /dev/null +++ b/marked/Y/T-REC-Y.2255-201801-I_PDF-E/a83ba9e3e2c1e21dd69953a7b09e45b4_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:3d2bc0a516795d79d975504e310de407ab236220a7941dbaff25b7f3cc564778 +size 73243 diff --git a/marked/Y/T-REC-Y.2255-201801-I_PDF-E/b6671cfafda3820aafe9a24fa7a4d8c7_img.jpg b/marked/Y/T-REC-Y.2255-201801-I_PDF-E/b6671cfafda3820aafe9a24fa7a4d8c7_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..b1f880eb5b4795779e9139b5d91e01a254ef0908 --- /dev/null +++ b/marked/Y/T-REC-Y.2255-201801-I_PDF-E/b6671cfafda3820aafe9a24fa7a4d8c7_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:1745971fa52c3453c6321fe2d9e630af3064d630f3b957eda2a492ed67d5d2e1 +size 85018 diff --git a/marked/Y/T-REC-Y.2255-201801-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg b/marked/Y/T-REC-Y.2255-201801-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..3a391fcd8cb1bfe11aea84f0d91f446ea4296cfc --- /dev/null +++ b/marked/Y/T-REC-Y.2255-201801-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:d8e7af00201538c910ae9f18773afa7a938d627e14ed1887c77ec30b54a7e297 +size 94634 diff --git a/marked/Y/T-REC-Y.2323-201812-I_PDF-E/14a22f23ced8ba1d63ece69861dbaacc_img.jpg b/marked/Y/T-REC-Y.2323-201812-I_PDF-E/14a22f23ced8ba1d63ece69861dbaacc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..ac9a131b90c40170df62d785730d53915bf40ca4 --- /dev/null +++ b/marked/Y/T-REC-Y.2323-201812-I_PDF-E/14a22f23ced8ba1d63ece69861dbaacc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:8b8356aebbd45ffb910c8524cc5298dcf4d9b5db3e0cdbaf34a6ae621dd189db +size 4115 diff --git a/marked/Y/T-REC-Y.2323-201812-I_PDF-E/5cab96b2d23174c25919840ecd50aa48_img.jpg b/marked/Y/T-REC-Y.2323-201812-I_PDF-E/5cab96b2d23174c25919840ecd50aa48_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..c6131574a5d6b4819d98c25a69fbfa0075c446e8 --- /dev/null +++ b/marked/Y/T-REC-Y.2323-201812-I_PDF-E/5cab96b2d23174c25919840ecd50aa48_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:98dfccea5937b1f06cee4ce3f027977efdb672e112384cb4c77e11ae64ab0389 +size 48585 diff --git a/marked/Y/T-REC-Y.2323-201812-I_PDF-E/75f0cb39f1cd165dfe4a6aa6c4d9388d_img.jpg b/marked/Y/T-REC-Y.2323-201812-I_PDF-E/75f0cb39f1cd165dfe4a6aa6c4d9388d_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..89acccb55c69b531a9ccb7074885e54770d660cb --- /dev/null +++ b/marked/Y/T-REC-Y.2323-201812-I_PDF-E/75f0cb39f1cd165dfe4a6aa6c4d9388d_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:e9e914c89d8f75eeb984b6215be9b41dfb6ac1f23ec18b65f0a0352a99a90372 +size 61650 diff --git a/marked/Y/T-REC-Y.2323-201812-I_PDF-E/a83ba9e3e2c1e21dd69953a7b09e45b4_img.jpg b/marked/Y/T-REC-Y.2323-201812-I_PDF-E/a83ba9e3e2c1e21dd69953a7b09e45b4_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..74bae86006f4851514550a5b847e0784e70051f5 --- /dev/null +++ b/marked/Y/T-REC-Y.2323-201812-I_PDF-E/a83ba9e3e2c1e21dd69953a7b09e45b4_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:3a1bda1848901b4109494462f5bd82cd80fff4e91e3873354276de73d2620e80 +size 34349 diff --git a/marked/Y/T-REC-Y.2323-201812-I_PDF-E/b28af4985cdef1e519e3aaf26561dcb3_img.jpg b/marked/Y/T-REC-Y.2323-201812-I_PDF-E/b28af4985cdef1e519e3aaf26561dcb3_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..06ea21858084ef1e4faa859b9c144c6ee7a409ea --- /dev/null +++ b/marked/Y/T-REC-Y.2323-201812-I_PDF-E/b28af4985cdef1e519e3aaf26561dcb3_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:cf0d606ba15f47e009d414cd80abae5308c6e7eb9d8c171029f419b01581a187 +size 38360 diff --git a/marked/Y/T-REC-Y.2325-202312-I_PDF-E/2d4807f80a3f0106f1722d5722cfac87_img.jpg b/marked/Y/T-REC-Y.2325-202312-I_PDF-E/2d4807f80a3f0106f1722d5722cfac87_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..d4d8969f805414689ab79cfd08c333d454d482b3 --- /dev/null +++ b/marked/Y/T-REC-Y.2325-202312-I_PDF-E/2d4807f80a3f0106f1722d5722cfac87_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:636c3839edff955a5b6208530b05fa1c983ab153d90f00216517a7a99478b988 +size 7074 diff --git a/marked/Y/T-REC-Y.2325-202312-I_PDF-E/5cab96b2d23174c25919840ecd50aa48_img.jpg b/marked/Y/T-REC-Y.2325-202312-I_PDF-E/5cab96b2d23174c25919840ecd50aa48_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..66297af551e3a083fa9859f95c0e210a73ef4b88 --- /dev/null +++ b/marked/Y/T-REC-Y.2325-202312-I_PDF-E/5cab96b2d23174c25919840ecd50aa48_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:21f8525cba80392c7e28f195c1aebd86a8f5d661db3c4065dfbc825156abfbc9 +size 161582 diff --git a/marked/Y/T-REC-Y.2325-202312-I_PDF-E/5e92d9e8e9ce204e405bff2367f88176_img.jpg b/marked/Y/T-REC-Y.2325-202312-I_PDF-E/5e92d9e8e9ce204e405bff2367f88176_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..8eb8762324f018f8486ee0952054a455f13f70e9 --- /dev/null +++ b/marked/Y/T-REC-Y.2325-202312-I_PDF-E/5e92d9e8e9ce204e405bff2367f88176_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:01091d4b6eedac88c6bd4d50ad901cfb52701600eeac8bd76c982641d993007e +size 34664 diff --git a/marked/Y/T-REC-Y.2325-202312-I_PDF-E/812e188283162af0b54fb3e30ffee51b_img.jpg b/marked/Y/T-REC-Y.2325-202312-I_PDF-E/812e188283162af0b54fb3e30ffee51b_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..c2637bec67695709bdcd95582c52e57ff0bdb4e4 --- /dev/null +++ b/marked/Y/T-REC-Y.2325-202312-I_PDF-E/812e188283162af0b54fb3e30ffee51b_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:d728b59c75a6285ba6f96212dba14637417cfa51191c331df9db04453608d408 +size 63856 diff --git a/marked/Y/T-REC-Y.2325-202312-I_PDF-E/a33da0f14e456f92539ce3e9b7d81f9a_img.jpg b/marked/Y/T-REC-Y.2325-202312-I_PDF-E/a33da0f14e456f92539ce3e9b7d81f9a_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..bb2aa8d12651c45e7e4e0e4878eaad0cae5273c4 --- /dev/null +++ b/marked/Y/T-REC-Y.2325-202312-I_PDF-E/a33da0f14e456f92539ce3e9b7d81f9a_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:78aed521cb1003fdec91a3ae935b8ba5b331239fa81a76022dbe36d05d07c075 +size 50861 diff --git a/marked/Y/T-REC-Y.2325-202312-I_PDF-E/c5452f95f3b28f1bfe29e84fbc2e1267_img.jpg b/marked/Y/T-REC-Y.2325-202312-I_PDF-E/c5452f95f3b28f1bfe29e84fbc2e1267_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..400f48be15bd45a7015e4ac352841508f72c44b2 --- /dev/null +++ b/marked/Y/T-REC-Y.2325-202312-I_PDF-E/c5452f95f3b28f1bfe29e84fbc2e1267_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:b94aca32b57ba9ee379b9db6b27fbc1bf59f8f9e58aaba9e14bdddc037b801c3 +size 174993 diff --git a/marked/Y/T-REC-Y.2325-202312-I_PDF-E/c85ded401105f62f2d6ff26b3b5eb4af_img.jpg b/marked/Y/T-REC-Y.2325-202312-I_PDF-E/c85ded401105f62f2d6ff26b3b5eb4af_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..ec279cdaf057366f390f887c24d891da7187bf3a --- /dev/null +++ b/marked/Y/T-REC-Y.2325-202312-I_PDF-E/c85ded401105f62f2d6ff26b3b5eb4af_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:c181a70ca209fd06b53da7bf56b7a85bbc4260229fa36d8d399b5163265b49f1 +size 113811 diff --git a/marked/Y/T-REC-Y.2325-202312-I_PDF-E/d26959f4514c26ca19c3d6f00da85956_img.jpg b/marked/Y/T-REC-Y.2325-202312-I_PDF-E/d26959f4514c26ca19c3d6f00da85956_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..76cc418663c31e8e138191128b079979d0713dc8 --- /dev/null +++ b/marked/Y/T-REC-Y.2325-202312-I_PDF-E/d26959f4514c26ca19c3d6f00da85956_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:9a1fe9708c0fe32937fba9831116663fe9310bd6b300e2b0487d948378100ced +size 62410 diff --git a/marked/Y/T-REC-Y.2325-202312-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg b/marked/Y/T-REC-Y.2325-202312-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..193474b786ad070d4d49f966a2c6f88a26dbf696 --- /dev/null +++ b/marked/Y/T-REC-Y.2325-202312-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:83d6b7cc75cf63c94c6ad6fbb2509b916d2a9acc4fa5f07883986e08c572a677 +size 48251 diff --git a/marked/Y/T-REC-Y.2325-202312-I_PDF-E/ddc7460821484f1ae2835c67955c554c_img.jpg b/marked/Y/T-REC-Y.2325-202312-I_PDF-E/ddc7460821484f1ae2835c67955c554c_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..0005f6b973911d0ffdb54758483ca0fc1fc54802 --- /dev/null +++ b/marked/Y/T-REC-Y.2325-202312-I_PDF-E/ddc7460821484f1ae2835c67955c554c_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:c0b2d8e7532dac469249c4dde34db954816dac65d4e4fb50ab2f40ddf52b70df +size 76369 diff --git a/marked/Y/T-REC-Y.2325-202312-I_PDF-E/e69b9188aa2c14ec6b21c83f711fef65_img.jpg b/marked/Y/T-REC-Y.2325-202312-I_PDF-E/e69b9188aa2c14ec6b21c83f711fef65_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..c5462b84203ba11bd90af70d2a08a029a91cd799 --- /dev/null +++ b/marked/Y/T-REC-Y.2325-202312-I_PDF-E/e69b9188aa2c14ec6b21c83f711fef65_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:be5c72c866f3a9758ab2caaf9e2bf045005bb927fd190648e17d90a9ca5fa5d3 +size 83362 diff --git a/marked/Y/T-REC-Y.2325-202312-I_PDF-E/eaae122ace5c0d761133c6ce971a6ffd_img.jpg b/marked/Y/T-REC-Y.2325-202312-I_PDF-E/eaae122ace5c0d761133c6ce971a6ffd_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..feed731ab777c17dd3c5a4b79adccecf18d3c8b1 --- /dev/null +++ b/marked/Y/T-REC-Y.2325-202312-I_PDF-E/eaae122ace5c0d761133c6ce971a6ffd_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:617e44aaf236147a43a4b8ffbae0bfd58b3bcdf6d200a65d28f51c034be009fb +size 128316 diff --git a/marked/Y/T-REC-Y.2325-202312-I_PDF-E/ff0952ef692c9d960ce5f6708bcc9711_img.jpg b/marked/Y/T-REC-Y.2325-202312-I_PDF-E/ff0952ef692c9d960ce5f6708bcc9711_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..1706d99803a2a0fd5f0152fb56392ce9684873f4 --- /dev/null +++ b/marked/Y/T-REC-Y.2325-202312-I_PDF-E/ff0952ef692c9d960ce5f6708bcc9711_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:9dbad6e631691387bda82726ec996492940d8a38f97d8de97abc5182d3bc565c +size 65655 diff --git a/marked/Y/T-REC-Y.2325-202312-I_PDF-E/raw.md b/marked/Y/T-REC-Y.2325-202312-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..d9923e9fe927284d94553771d5ae5b039c7c269b --- /dev/null +++ b/marked/Y/T-REC-Y.2325-202312-I_PDF-E/raw.md @@ -0,0 +1,718 @@ + + +# Recommendation + +## **ITU-T Y.2325 (12/2023)** + +SERIES Y: Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities + +Next Generation Networks – Enhancements to NGN + +--- + +**Architectural evolution for the next generation network control plane by applying software-defined networking technology** + +## ITU-T Y-SERIES RECOMMENDATIONS + +## Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities + +| | | +|-------------------------------------------------------------------|----------------------| +| GLOBAL INFORMATION INFRASTRUCTURE | Y.100-Y.999 | +| INTERNET PROTOCOL ASPECTS | Y.1000-Y.1999 | +| NEXT GENERATION NETWORKS | Y.2000-Y.2999 | +| Frameworks and functional architecture models | Y.2000-Y.2099 | +| Quality of Service and performance | Y.2100-Y.2199 | +| Service aspects: Service capabilities and service architecture | Y.2200-Y.2249 | +| Service aspects: Interoperability of services and networks in NGN | Y.2250-Y.2299 | +| Enhancements to NGN | Y.2300-Y.2399 | +| Network management | Y.2400-Y.2499 | +| Computing power networks | Y.2500-Y.2599 | +| Packet-based Networks | Y.2600-Y.2699 | +| Security | Y.2700-Y.2799 | +| Generalized mobility | Y.2800-Y.2899 | +| Carrier grade open environment | Y.2900-Y.2999 | +| FUTURE NETWORKS | Y.3000-Y.3499 | +| CLOUD COMPUTING | Y.3500-Y.3599 | +| BIG DATA | Y.3600-Y.3799 | +| QUANTUM KEY DISTRIBUTION NETWORKS | Y.3800-Y.3999 | +| INTERNET OF THINGS AND SMART CITIES AND COMMUNITIES | Y.4000-Y.4999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T Y.2325 + +# Architectural evolution for the next generation network control plane by applying software-defined networking technology + +## Summary + +Recommendation ITU-T Y.2325 aims to standardize an evolved NGN control plane architecture that is scalable, simplified and flexible, by decoupling the end-user signalling handling functionality and the user plane control functionality and also treating the signalling as a user service (data) leading to uniform handling of services. This Recommendation includes the description of information flow for services such as network attachment, session establishment and registration for the recommended architecture. + +## History \* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T Y.2325 | 2023-12-14 | 13 | 11.1002/1000/15732 | + +## Keywords + +Next generation network, NGN, software-defined networking, SDN. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2024 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +# Table of Contents + +| | | Page | +|----|-----------------------------------------------------------------------------------------------|------| +| 1 | Scope ..... | 1 | +| 2 | References..... | 1 | +| 3 | Definitions ..... | 2 | +| | 3.1 Terms defined elsewhere..... | 2 | +| | 3.2 Terms defined in this Recommendation..... | 3 | +| 4 | Abbreviations and acronyms ..... | 3 | +| 5 | Conventions ..... | 4 | +| 6 | Overview ..... | 4 | +| 7 | Requirements ..... | 4 | +| 8 | Evolved NGN control plane ..... | 5 | +| | 8.1 Conceptual framework for the evolved NGN control plane ..... | 5 | +| | 8.2 Recommended high-level architecture for evolved NGN control plane ..... | 7 | +| | 8.3 General service-based architecture based on SDN technology ..... | 8 | +| | 8.4 Placement and splitting of high-level functions in evolved NGN..... | 9 | +| 9 | High-level functions for network attachment service in evolved NGN ..... | 11 | +| | 9.1 Network attachment signalling service function ..... | 11 | +| | 9.2 Network attachment signalling service support function (NASSsupportF) ... | 12 | +| 10 | High-level functions for mobility service in evolved NGN ..... | 12 | +| | 10.1 Mobility signalling service function..... | 13 | +| | 10.2 Mobility signalling service support function (MSSsupportF)..... | 13 | +| 11 | General procedures for network attachment..... | 14 | +| | 11.1 Registration procedure..... | 14 | +| | 11.2 Session establishment procedure..... | 15 | +| | Appendix I..... | 17 | +| | A.I Network attachment procedure with mobility service (in case of host-based mobility) ..... | 17 | +| | Bibliography..... | 19 | + + + +# Recommendation ITU-T Y.2325 + +# Architectural evolution for the next generation network control plane by applying software-defined networking technology + +# 1 Scope + +This Recommendation specifies an evolved NGN control plane architecture that is scalable, simplified and flexible by decoupling the end-user signalling handling functionality and the user plane control functionality and also treating the signalling as a user service (data) leading to uniform handling of services. + +This Recommendation includes: + +- Requirements of the evolved NGN control plane architecture; +- Architecture to separate the end user-specific signalling exchange functionality from the user plane control (transport control) functionality for NGN architecture based on the SDN paradigm and network service model and also treating the signalling as a user service; +- Information flow for services such as network attachment, session establishment and registration. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +| | | +|----------------|------------------------------------------------------------------------------------------------------------------------------------------| +| [ITU-T Q.1743] | Recommendation ITU-T Q.1743 (2016), IMT-Advanced references to Release 11 of LTE-Advanced evolved packet core network . | +| [ITU-T Y.1910] | Recommendation ITU-T Y.1910 (2008), IPTV functional architecture . | +| [ITU-T Y.2011] | Recommendation ITU-T Y.2011 (2004), General principles and general reference model for Next Generation Networks . | +| [ITU-T Y.2012] | Recommendation ITU-T Y.2012 (2010), Functional requirements and architecture of next generation networks . | +| [ITU-T Y.2014] | Recommendation ITU-T Y.2014 (2010), Network attachment control functions in next generation networks . | +| [ITU-T Y.2018] | Recommendation ITU-T Y.2018 (2009), Mobility management and control framework and architecture within the NGN transport stratum . | +| [ITU-T Y.3300] | Recommendation ITU-T Y.3300 (2014), Framework of software-defined networking . | + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 authentication** [ITU-T Y.2014]: A property by which the correct identifier of an entity or party is established with a required assurance. The party being authenticated could be a user, subscriber, home environment or serving network. + +**3.1.2 control plane** [ITU-T Y.2011]: The set of functions that controls the operation of entities in the stratum or layer under consideration, plus the functions required to support this control. + +**3.1.3 customer premises equipment (CPE)** [ITU-T Y.2014]: One or more devices allowing a user to access services delivered by NGN. + +NOTE – This includes devices under user control commonly referred to as home gateway (HGW) or terminals (TE), etc., but not network-controlled entities, such as access gateways. + +**3.1.4 data plane** [ITU-T Y.2011]: The set of functions used to transfer data in the stratum or layer under consideration. + +**3.1.5 end user** [b-ITU-T M.3050.1]: The end user is the actual user of the products or services offered by the enterprise. The end user consumes the product or service. + +**3.1.6 functional architecture** [ITU-T Y.2012]: A set of functional entities and the reference points between them used to describe the structure of an NGN. These functional entities are separated by reference points, and thus, they define the distribution of functions. + +NOTE – The functional entities can be used to describe a set of reference configurations. These reference configurations identify which reference points are visible at the boundaries of equipment implementations and between administrative domains. + +**3.1.7 functional entity** [ITU-T Y.2012]: An entity that comprises an indivisible set of specific functions. Functional entities are logical concepts, while groupings of functional entities are used to describe practical, physical implementations. + +**3.1.8 home gateway (HGW)** [ITU-T Y.2014]: Gateway between the customer premises network (CPN) and the access network. + +NOTE – A home gateway may be in its simplest form a bridged or routed modem, and in a more advanced form be an integrated access device. + +**3.1.9 mobility** [b-ITU-T Q.1706]: The ability for the user or other mobile entities to communicate and access services irrespective of changes of the location or technical environment. + +**3.1.10 mobility management** [b-ITU-T Q.1706]: The set of functions used to provide mobility. These functions include authentication, authorization, location updating, paging, download of user information and more. + +**3.1.11 NGN service stratum** [ITU-T Y.2011]: That part of the NGN which provides the user functions that transfer service-related data and the functions that control and manage service resources and network services to enable user services and applications. + +**3.1.12 NGN transport stratum** [ITU-T Y.2011]: That part of the NGN which provides the user functions that transfer data and the functions that control and manage transport resources to carry such data between terminating entities. + +**3.1.13 reference point** [ITU-T Y.2012]: A conceptual point at the conjunction of two non-overlapping functional entities that can be used to identify the type of information passing between these functional entities. + +NOTE – A reference point may correspond to one or more physical interfaces between pieces of equipment. + +**3.1.14 resource** [b-ITU-T M.3050.1]: Resources represent physical and non-physical components used to construct services. They are drawn from the application, computing and network domains and include, for example, network elements, software, IT systems and technology components. + +**3.1.15 software defined networking** [ITU-T Y.3300]: A set of techniques that enables to directly program, orchestrate, control and manage network resources, which facilitates the design, delivery and operation of network services in a dynamic and scalable manner. + +**3.1.16 user equipment (UE)** [ITU-T Q.1743]: A device allowing a user access to network services. For the purpose of 3GPP specifications, the interface between the UE and the network is the radio interface. A[n item of] user equipment can be subdivided into a number of domains, the domains being separated by reference points. Currently defined domains are the USIM and ME Domains. The ME Domain can further be subdivided into several components showing the connectivity between multiple functional groups. These groups can be implemented in one or more hardware devices. An example of such a connectivity is the TE-MT interface. Further, an occurrence of a user equipment is a MS for GSM. + +**3.1.17 user plane** [ITU-T Y.2011]: A synonym for data plane. + +## **3.2 Terms defined in this Recommendation** + +This Recommendation defines the following term: + +**3.2.1 built-in service:** User services inherent to next generation networks such as support for data communication, user authentication or user mobility. The built-in services form the basis for more advanced services such as video streaming or gaming. + +# **4 Abbreviations and acronyms** + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|--------------|--------------------------------------------------------| +| AR-FE | Access Relay Functional Entity | +| ASF | Application Support Function | +| CDF | Content Distribution Function | +| CPE | Customer Premises Equipment | +| EUE | End User Equipment | +| HGW | Home Gateway | +| IP | Internet Protocol | +| IPTV | Internet Protocol Television | +| MMCF | Mobility Management and Control Function | +| MSSF | Mobility Signalling Service Function | +| MSSsupportF | Mobility Signalling Service support Function | +| NACF | Network Attachment Control Function | +| NASSF | Network Attachment Signalling Service Function | +| NASSsupportF | Network Attachment Signalling Service support Function | +| NGN | Next Generation Networks | +| QoS | Quality of Service | +| RACF | Resource Admission and Control Function | +| SDN | Software Defined Networking | + +| | | +|------------|-------------------------------------| +| SSF | Service Support Function | +| SigSF | Signalling Service Function | +| SSsupportF | Signalling Service support Function | +| UE | User Equipment | + +# 5 Conventions + +In this Recommendation, requirements are classified as follows: + +- The keywords "**is required to**" or "**are required to**" indicate one or more requirements that must be strictly followed and from which no deviation is permitted if conformance to this document is to be claimed; +- The keywords "**is recommended**" indicate a requirement that is recommended but not absolutely required. Thus, such requirements need not be present to claim conformance; and +- The keywords "**optionally**" or "**may**" indicate an optional requirement which is permissible, without implying any sense of being recommended. These terms are not intended to imply that the vendor's implementation must provide the option; it means the vendor may optionally provide the feature and still claim conformance with the specification. + +# 6 Overview + +The existing NGN architecture, per [ITU-T Y.2012], supports a separation between the control plane and the user plane. NGN control plane functions (or control functions) are responsible for controlling network resources, i.e., the establishment, modification or deletion of sessions over the underlying network resources (hereinafter referred to as "resource allocation (control)"). In addition to resource allocation, the control functions are also responsible for the exchange of signalling messages with the end user (hereinafter referred to as "signalling handling"). These two categories of functionalities, "signalling handling" and "resource allocation (control)", are logically separate functionalities that are tightly coupled within the control plane of existing NGN architecture. + +Further, the control functions in NGN (as in [ITU-T Y.2012]) can be mapped with the functionality of the software defined networking (SDN) control layer as well as to the application (or service) layer (as in [ITU-T Y.3300]). + +This Recommendation offers an evolved NGN control plane architecture with improved alignment to SDN principles as elucidated in [ITU-T Y.3300] based on the existing NGN architecture per [ITU-T Y.2012], wherein signalling handling functionality is treated as a service (application) by decoupling the "signalling handling functionality" from the "resource allocation (control) functionality". By treating end user-associated signalling as a service (application), the Recommendation aims to arrive at a service-driven SDN-based architecture for the next generation networks, where all services (applications) are handled in a uniform manner, whether these are built-in services such as user mobility or external services such as media streaming or Internet protocol (IP) multimedia subsystem services. As a result, the evolved NGN control plane architecture in this Recommendation is more scalable, simplified and flexible with simplified information flows and improved alignment with SDN principles. + +# 7 Requirements + +The evolved NGN control plane architecture is required to: + +- a) be aligned with software defined networking (SDN) technology by decoupling "resource allocation" and "signalling exchange with end users" functionalities and separating them via a standardized interface; + +- b) have provision for potentially different signalling message exchange for different use cases to support use case specific signalling overhead; +- c) facilitate dynamic deployment of signalling service functions; and +- d) provide uniform treatment to built-in and external services to bring simplicity to the procedures and architecture. + +# 8 Evolved NGN control plane + +## 8.1 Conceptual framework for the evolved NGN control plane + +In the existing NGN architecture, per [ITU-T Y.2011] and [ITU-T Y.2012], "signalling handling functionality" and the "resource allocation (control) functionality" are both tightly coupled within the NGN control plane (as shown in Figure 8-1). Decoupling of the "signalling handling functionality" from the "resource allocation (control) functionality" is required to separate end user signalling handling from the control plane (as shown in Figure 8-2) and further, to handle end user signalling via a signalling service function (as shown in Figure 8-3). End user signalling messages may be treated as another form of data flowing through the network. + +![Figure 8-1: Overview of the existing NGN architecture and high-level functionality distribution. The diagram shows two strata on the left: 'NGN service stratum' and 'NGN transport stratum'. Each stratum is divided into three planes: 'Management plane', 'Control plane', and 'User plane'. Arrows from the 'Control plane' of both strata point to a central 'NGN control plane' block. This block contains a yellow box labeled 'Resource allocation (Control) and signalling exchange with end user for built-in-services', a green box labeled 'Resources', and an orange box labeled 'End user'. Bidirectional arrows connect the yellow box to the 'Resources' box, and the 'Resources' box to the 'End user' box. A blue arrow also points from the yellow box to the 'End user' box. The diagram is labeled 'Y.2011_F01' and 'Y.2325(23)'.](d26959f4514c26ca19c3d6f00da85956_img.jpg) + +Figure 8-1: Overview of the existing NGN architecture and high-level functionality distribution. The diagram shows two strata on the left: 'NGN service stratum' and 'NGN transport stratum'. Each stratum is divided into three planes: 'Management plane', 'Control plane', and 'User plane'. Arrows from the 'Control plane' of both strata point to a central 'NGN control plane' block. This block contains a yellow box labeled 'Resource allocation (Control) and signalling exchange with end user for built-in-services', a green box labeled 'Resources', and an orange box labeled 'End user'. Bidirectional arrows connect the yellow box to the 'Resources' box, and the 'Resources' box to the 'End user' box. A blue arrow also points from the yellow box to the 'End user' box. The diagram is labeled 'Y.2011\_F01' and 'Y.2325(23)'. + +**Figure 8-1 – Overview of the existing NGN architecture and high-level functionality distribution** + +![Figure 8-2: Decoupling of resource control functions and signalling handling functions in control plane. The diagram shows a 'Decoupled control functions' block containing two blue boxes: 'Resource allocation (Control functions)' and 'Signalling service functions'. These two boxes are connected by a bidirectional arrow. Below this block is a green box labeled 'Resources', and at the bottom is an orange box labeled 'End user'. Bidirectional arrows connect the 'Resource allocation' box to the 'Resources' box, and the 'Signalling service functions' box to the 'End user' box. The diagram is labeled 'Y.2325(23)'.](5e92d9e8e9ce204e405bff2367f88176_img.jpg) + +Figure 8-2: Decoupling of resource control functions and signalling handling functions in control plane. The diagram shows a 'Decoupled control functions' block containing two blue boxes: 'Resource allocation (Control functions)' and 'Signalling service functions'. These two boxes are connected by a bidirectional arrow. Below this block is a green box labeled 'Resources', and at the bottom is an orange box labeled 'End user'. Bidirectional arrows connect the 'Resource allocation' box to the 'Resources' box, and the 'Signalling service functions' box to the 'End user' box. The diagram is labeled 'Y.2325(23)'. + +**Figure 8-2 – Decoupling of resource control functions and signalling handling functions in control plane** + +![Figure 8-3: Decoupled signalling service functions from the NGN control plane. The diagram shows a hierarchical structure. At the top is a light blue rounded rectangle labeled 'NGN control plane'. Inside it is a yellow rounded rectangle labeled 'Resource allocation functions (Resource control)'. Inside the yellow rectangle is a blue rectangle labeled 'Manage resource allocation and interact with signalling service functions'. To the right of the yellow rectangle is a blue rectangle labeled 'Signalling service functions'. Below the yellow rectangle is a green rounded rectangle labeled 'Resources'. At the bottom is an orange rounded rectangle labeled 'End user'. Arrows indicate interactions: a double-headed arrow between the blue box inside the yellow box and the 'Signalling service functions' box; a double-headed arrow between the yellow box and the 'Resources' box; a single-headed arrow from the 'Resources' box to the 'End user' box; and a single-headed arrow from the 'Signalling service functions' box to the 'End user' box. The text 'Y.2325(23)' is located at the bottom right of the diagram.](d4af765160d04ecef538e5066006dc77_img.jpg) + +Figure 8-3: Decoupled signalling service functions from the NGN control plane. The diagram shows a hierarchical structure. At the top is a light blue rounded rectangle labeled 'NGN control plane'. Inside it is a yellow rounded rectangle labeled 'Resource allocation functions (Resource control)'. Inside the yellow rectangle is a blue rectangle labeled 'Manage resource allocation and interact with signalling service functions'. To the right of the yellow rectangle is a blue rectangle labeled 'Signalling service functions'. Below the yellow rectangle is a green rounded rectangle labeled 'Resources'. At the bottom is an orange rounded rectangle labeled 'End user'. Arrows indicate interactions: a double-headed arrow between the blue box inside the yellow box and the 'Signalling service functions' box; a double-headed arrow between the yellow box and the 'Resources' box; a single-headed arrow from the 'Resources' box to the 'End user' box; and a single-headed arrow from the 'Signalling service functions' box to the 'End user' box. The text 'Y.2325(23)' is located at the bottom right of the diagram. + +**Figure 8-3 – Decoupled signalling service functions from the NGN control plane** + +The separation of signalling handling functionality from the control plane in the transport stratum is detailed below. + +A subset of transport control functionality involves controlling and managing transport functions, i.e., management (establishment/modification/deletion) of data sessions via user plane (transport functions). This subset is hereinafter recommended to be denoted as "resource allocation (control) functions". The other set of functionalities is responsible for exchanging signalling messages with end users and providing built-in services to them either directly via signalling exchange or indirectly by enabling the services with the help of the resource allocation (control) functions; this functionality is recommended to be denoted "signalling service functionality" and transposed to separate "signalling service functions". + +NOTE 1 – The signalling service function handles signalling exchange with end user equipment (EUE) to provide support for built-in service(s). + +For example, in order to provide a mobility service, when a user is moving, the signalling service functions may interact with the mobile user to obtain its location update and provide the same to the resource allocation (control) functions for further processing, i.e., to set up new and release old data paths through the transport functions. + +NOTE 2 – The term "EUE refers to UE [ITU-T Q.1743] as well as customer premises equipment (CPE) [ITU-T Y.2014]. EUE is not impacted by the recommended changes in the NGN control plane architecture. + +While it is recommended to keep the resource allocation (control) functions within the transport stratum control plane (SDN control layer), the signalling exchange functionality is recommended to be decoupled from the resource allocation (control) functions and moved out of the control plane. + +This Recommendation includes new signalling service functions to handle the exchange of signalling messages with end users. The evolved NGN transport control plane is required to contain only the resource allocation (control) functionality. These signalling service functions are also required to enable other services such as data transfer or user mobility by collecting relevant information (requirements) from end users through signalling exchange and providing the information for the configuration of transport functions via the transport control functions in order to support the appropriate service-aware behaviour. + +Once decoupled, these signalling service functions are required to be treated like external application-based services. Similar to the application service-based architecture for service delivery, the signalling related to a built-in service may be exchanged with an end user over a data path (i.e., a signalling path) by signalling service functions. The transport control functions are required to + +interact with signalling service functions (and not with an end user directly) via service stratum and manage the required data path for service, e.g., network attachment or mobility. + +## 8.2 Recommended high-level architecture for evolved NGN control plane + +Figure 8-4 provides an overview of the existing NGN architecture. In this architecture, mobility management and NACFs are part of transport control functions. These control functions collect information from end users to execute mobility management and network attachment procedures. This control information exchange or signalling is tightly coupled with resource control protocols/interfaces in the existing architecture. + +![Figure 8-4: NGN architecture overview. This diagram shows a layered architecture. At the top is the 'Service stratum' (green box) containing 'Application support functions and service support functions' and 'Service control and content delivery functions'. Below it is the 'Transport stratum' (yellow box) containing 'Transport control functions (Responsible for resource and admission control functionalities and also for providing built-in network services like mobility and network attachment)' and 'Transport functions'. At the bottom is the 'End user' (orange box). To the right is a vertical box labeled 'Application service provider'. A line connects the 'Service control and content delivery functions' to the 'Application service provider'. Another line connects the 'Transport control functions' to the 'Application service provider'. A third line connects the 'Transport functions' to the 'Application service provider'. The reference 'Y.2325(23)' is at the bottom right.](ff0952ef692c9d960ce5f6708bcc9711_img.jpg) + +Figure 8-4: NGN architecture overview. This diagram shows a layered architecture. At the top is the 'Service stratum' (green box) containing 'Application support functions and service support functions' and 'Service control and content delivery functions'. Below it is the 'Transport stratum' (yellow box) containing 'Transport control functions (Responsible for resource and admission control functionalities and also for providing built-in network services like mobility and network attachment)' and 'Transport functions'. At the bottom is the 'End user' (orange box). To the right is a vertical box labeled 'Application service provider'. A line connects the 'Service control and content delivery functions' to the 'Application service provider'. Another line connects the 'Transport control functions' to the 'Application service provider'. A third line connects the 'Transport functions' to the 'Application service provider'. The reference 'Y.2325(23)' is at the bottom right. + +**Figure 8-4 – NGN architecture overview** + +(Conceptual representation based on Figure 7-1 of [ITU-T Y.2012]) + +![Figure 8-5: Architecture overview for evolved NGN control plane. This diagram shows a layered architecture. At the top is the 'Service stratum' (green box) containing 'Application support functions and service support functions' and 'Service control and content delivery functions'. Below it is the 'Transport stratum' (yellow box) containing 'Resource and admission control functions' and 'Transport control functions', and 'Transport functions'. At the bottom is the 'End user' (orange box). To the right is a large box labeled 'Applications' containing 'Built-in network services such as mobility and network attachment signalling services' and 'External services'. A line connects the 'Service control and content delivery functions' to the 'Applications' box. Another line connects the 'Transport control functions' to the 'Applications' box. A third line connects the 'Transport functions' to the 'Applications' box. The reference 'Y.2325(23)' is at the bottom right.](ddc7460821484f1ae2835c67955c554c_img.jpg) + +Figure 8-5: Architecture overview for evolved NGN control plane. This diagram shows a layered architecture. At the top is the 'Service stratum' (green box) containing 'Application support functions and service support functions' and 'Service control and content delivery functions'. Below it is the 'Transport stratum' (yellow box) containing 'Resource and admission control functions' and 'Transport control functions', and 'Transport functions'. At the bottom is the 'End user' (orange box). To the right is a large box labeled 'Applications' containing 'Built-in network services such as mobility and network attachment signalling services' and 'External services'. A line connects the 'Service control and content delivery functions' to the 'Applications' box. Another line connects the 'Transport control functions' to the 'Applications' box. A third line connects the 'Transport functions' to the 'Applications' box. The reference 'Y.2325(23)' is at the bottom right. + +**Figure 8-5 – Architecture overview for evolved NGN control plane** + +As shown in Figure 8-5, the recommended architecture of the evolved NGN control plane provides improved segregation of functionality in the network control plane (transport control functions). Signalling functions for built-in services such as mobility and network attachment can be thought of as a signalling service function and can be moved out as applications in this evolved architecture. The tasks of these service functions include collecting requirements from end users for service delivery, sending requirements to resource allocation (transport control) functions via service stratum for configuration of transport functions and confirming back to the end user that the requirements have been met, whereas (transport) control functions include resource and admission control functionality and only act as the SDN controller to set up the data path through the transport functions. + +## 8.3 General service-based architecture based on SDN technology + +The concept of service-based architecture applied in this Recommendation is the same as how an (external) application provides a service to an end user in the NGN architecture. An application interacts with the network via standardized interfaces, with the control plane (transport stratum control functions via service stratum's application support functions (ASFs) and service support functions (SSFs) as well as the data plane (transport functions via service stratum's content delivery function (CDF)) as shown in Figure 8-6. For example, in the case of internet protocol television (IPTV) service, the IPTV application function sends IPTV content to the transport functions via the CDF of the service stratum to be forwarded to the end users (as shown in Figure 9-1 of [ITU-T Y.1910]). In addition, it also interacts with the transport control functions via the ASF and SSF for the establishment of the service session through the network to be used for service delivery. An important point to note here is that the application may also need to interact with the end users before setting up the service sessions. This signalling message exchange between the end user and application provides the requirements to the application for the service session to be established later (via network) to deliver the service to end users. Here, the initial signalling exchange between the end user and application also takes place over a session established earlier. This session may have been specifically established for signalling exchange but is similar to the service session used for delivery of service (data). Application itself cannot set up this session for signalling exchange through transport functions but requests the control functions (in transport stratum) via service stratum to set up the session through the transport functions. + +![Figure 8-6: Interfaces between an external application and NGN. The diagram shows the interaction between an external application and the NGN architecture. The external application (Application service provider) interacts with the Service stratum (Application support functions and service support functions, Service control and content delivery functions). The Service stratum interacts with the Transport stratum (Transport control functions (Control plane), Transport functions (User plane)). The Transport stratum interacts with the End user. A legend indicates: Control + data (black arrow), Control (blue arrow), and Data (red arrow).](a33da0f14e456f92539ce3e9b7d81f9a_img.jpg) + +The diagram illustrates the interfaces between an external application and the NGN architecture. It shows the following components and their interactions: + +- External Application:** Represented by a grey box labeled "Application service provider". +- Service stratum:** A green box containing two sub-components: + - Application support functions and service support functions:** Interacts with the external application via control and data paths. + - Service control and content delivery functions:** Interacts with the transport stratum. +- Transport stratum:** A yellow box containing two sub-components: + - Transport control functions (Control plane):** Interacts with the service stratum and the transport functions. + - Transport functions (User plane):** Interacts with the transport control functions and the end user. +- End user:** An orange box at the bottom that interacts with the transport functions. + +**Legend:** + +- Black arrow: Control + data +- Blue arrow: Control +- Red arrow: Data + +Y.2325(23) + +Figure 8-6: Interfaces between an external application and NGN. The diagram shows the interaction between an external application and the NGN architecture. The external application (Application service provider) interacts with the Service stratum (Application support functions and service support functions, Service control and content delivery functions). The Service stratum interacts with the Transport stratum (Transport control functions (Control plane), Transport functions (User plane)). The Transport stratum interacts with the End user. A legend indicates: Control + data (black arrow), Control (blue arrow), and Data (red arrow). + +Figure 8-6 – Interfaces between an external application and NGN + +As the applications are decoupled from the network and accesses it via service stratum to support the service delivery, the delivery of built-in services such as mobility can also be handled in the same way. Based on this concept, this Recommendation includes an evolved architecture for NGN control plane for the delivery of built-in services. The architecture applies SDN technology to NGN and considers built-in services as applications. Figure 8-7 shows the mapping of the evolved NGN control plane architecture with the SDN framework (as given in Figure 11-1 of [ITU-T Y.3300]). The modified transport control functions can be viewed as the SDN controller and a subset of ASFs and SSFs and the service control functions can be viewed as service orchestrators. The service orchestrators are responsible for the orchestration of services (including both external and built-in services) in the network. + +The facilitation of a service (external as well as built-in) to an end user typically involves two steps: + +- a) the collection of service specific requirements; and +- b) the establishment of a path for service delivery. + +However, as noted above, even collecting service specific requirements from a user may necessitate the establishment of a path (session) through the network. + +![Figure 8-7 – Handling of built-in services in evolved NGN architecture based on SDN technology](eaae122ace5c0d761133c6ce971a6ffd_img.jpg) + +The diagram illustrates the mapping between SDN layers and NGN strata. On the left, the SDN framework consists of three layers: Application layer (containing Application blocks), SDN control layer (containing Application support, Orchestration, and Abstraction), and Resource layer (containing Control support and Data transport and processing). A vertical block labeled 'Multi-layer management functions' spans all three. Interfaces between layers are labeled 'Application-control interface' and 'Resource-control interface'. + +On the right, the NGN architecture consists of the Service stratum (containing Application support functions and service support functions, Service control functions, and Content delivery functions) and the Transport stratum (containing Transport control functions (Control plane) and Transport functions (User plane)). Above these are 'Applications' (Built-in and External), and below is the 'End user'. + +Flows are indicated by colored arrows: Black for 'Control + data', Blue for 'Control', and Red for 'Data'. These flows connect the End user through the strata to the Applications. + +**Figure 8-7 – Handling of built-in services in evolved NGN architecture +based on SDN technology** + +Figure 8-7 – Handling of built-in services in evolved NGN architecture based on SDN technology + +**8.4 Placement and splitting of high-level functions in evolved NGN** + +In the existing NGN architecture, the transport control functions consist of three high-level functions, resource and admission control functions (RACFs), NACFs, and mobility management and control Functions (MMCFs) as shown in Figure 8-8. In evolved NGN, mobility and network attachment are considered as built-in services and are handled in the same manner as external services/applications are handled in the network. To support these built-in services, high-level functions NACF and MMCF are moved out from the transport control functions and split into two categories of high-level functions named signalling service functions and signalling service support functions (as shown in + +**Rec. ITU-T Y.2325 (12/2023)**       9 + +Figure 8-9). The signalling service function is a function in the application layer. The signalling service support function is a function in the service stratum, which provides support for built-in service(s). These functions are responsible for end user signalling and to collect/provide service-related information for built-in services. Functionalities of service orchestration functions (in the service stratum) include control and management of network resources, and coordination of requests for network resources. These functionalities are aligned with the orchestration functionalities of the SDN control layer (described in clause 11.2 of [ITU-T Y.3300]). + +![Figure 8-8: Existing NGN architecture and high-level functions. The diagram illustrates the NGN architecture layers and their interactions. At the top is the 'Applications' layer (light blue). Below it is the 'Service stratum' (green), which contains 'Application support functions and service support functions' and 'Service control and content delivery functions'. The 'Service control and content delivery functions' are further divided into 'Service user profiles' (a cylinder), 'Service control functions', and 'Content delivery functions'. Below the Service stratum is the 'Transport stratum' (yellow), which contains 'Network attachment and control functions' (with 'Transport user profiles' cylinder), 'Mobility management and control functions', 'Resource and admission control functions', and 'Transport functions'. To the left, 'Management functions' (pink vertical bar) connects to 'IdM functions' (yellow box) and 'End-user functions' (white box). 'IdM functions' connects to the 'Service stratum' and 'Transport stratum'. 'End-user functions' connects to the 'Transport stratum'. On the right, 'Functions from other service providers' and 'Functions from other networks' are shown. Interfaces are labeled: ANI (Application Network Interface) between Applications and Service stratum; SNI (Service Network Interface) between Service stratum and other service providers; UNI (User Network Interface) between End-user functions and Transport stratum; and NNI (Network Network Interface) between Transport stratum and other networks. A legend at the bottom indicates: dashed black line for Control, solid blue line for Media, dashed pink line for Management, and dashed orange line for IdM. Reference Y.2325(23) is noted at the bottom right.](5cab96b2d23174c25919840ecd50aa48_img.jpg) + +Figure 8-8: Existing NGN architecture and high-level functions. The diagram illustrates the NGN architecture layers and their interactions. At the top is the 'Applications' layer (light blue). Below it is the 'Service stratum' (green), which contains 'Application support functions and service support functions' and 'Service control and content delivery functions'. The 'Service control and content delivery functions' are further divided into 'Service user profiles' (a cylinder), 'Service control functions', and 'Content delivery functions'. Below the Service stratum is the 'Transport stratum' (yellow), which contains 'Network attachment and control functions' (with 'Transport user profiles' cylinder), 'Mobility management and control functions', 'Resource and admission control functions', and 'Transport functions'. To the left, 'Management functions' (pink vertical bar) connects to 'IdM functions' (yellow box) and 'End-user functions' (white box). 'IdM functions' connects to the 'Service stratum' and 'Transport stratum'. 'End-user functions' connects to the 'Transport stratum'. On the right, 'Functions from other service providers' and 'Functions from other networks' are shown. Interfaces are labeled: ANI (Application Network Interface) between Applications and Service stratum; SNI (Service Network Interface) between Service stratum and other service providers; UNI (User Network Interface) between End-user functions and Transport stratum; and NNI (Network Network Interface) between Transport stratum and other networks. A legend at the bottom indicates: dashed black line for Control, solid blue line for Media, dashed pink line for Management, and dashed orange line for IdM. Reference Y.2325(23) is noted at the bottom right. + +**Figure 8-8 – Existing NGN architecture and high-level functions** +[Source: ITU-T Y.2012] + +To support the network attachment service (a built-in service) as part of the evolved NGN architecture, the existing NACF functionalities as specified in [ITU-T Y.2014] are distributed among two new and separate functions, network attachment signalling service function (NASSF) and network attachment signalling service support function (NASSsupportF). NASSF is considered as an application (service) and NASSsupportF is placed in the service stratum as shown in Figure 8-9. Similarly, to support the mobility service as part of the evolved NGN architecture, the existing MMCF functionalities as specified in [ITU-T Y.2018] are also distributed among two new and separate functions, the mobility signalling service function (MSSF) and mobility signalling service support function (MSSsupportF). MSSF is considered an application (service) and the MSSsupportF is placed in the service stratum as shown in Figure 8-9. + +NOTE – For this Recommendation, network attachment and mobility services are taken as examples for built-in services. The above concept of distribution/placement of control functions can be applied for other built-in services also in evolved NGN. + +![Figure 8-9: Placement and splitting of high-level functions for network attachment and mobility services in evolved NGN. The diagram shows a layered architecture. On the left, the 'Service stratum' (green) contains 'Application support functions and service support functions' (MSSsupportF and NASSsupportF) and 'Service orchestration and content delivery functions'. Below it is the 'Transport stratum' (yellow) with 'Transport control functions' (RACF) and 'Transport functions'. At the bottom is the 'End user' (orange). On the right, the 'Applications' (blue) section includes 'Built-in network services' (NASSF, MSSF, and other built-in network signalling service functions) and 'External services'. Arrows indicate connections between the strata and the applications.](c85ded401105f62f2d6ff26b3b5eb4af_img.jpg) + +Y.2325(23) + +Figure 8-9: Placement and splitting of high-level functions for network attachment and mobility services in evolved NGN. The diagram shows a layered architecture. On the left, the 'Service stratum' (green) contains 'Application support functions and service support functions' (MSSsupportF and NASSsupportF) and 'Service orchestration and content delivery functions'. Below it is the 'Transport stratum' (yellow) with 'Transport control functions' (RACF) and 'Transport functions'. At the bottom is the 'End user' (orange). On the right, the 'Applications' (blue) section includes 'Built-in network services' (NASSF, MSSF, and other built-in network signalling service functions) and 'External services'. Arrows indicate connections between the strata and the applications. + +**Figure 8-9 – Placement and splitting of high-level functions for network attachment and mobility services in evolved NGN** + +# 9 High-level functions for network attachment service in evolved NGN + +In the existing NGN, the high-level function NACF provides registration at the access level (including EUE context creation and policy association) and initialization of EUE for accessing the NGN services. The NACF provides network level identification and authentication, manages the IP address space of the access network and authenticates access sessions. The NACF also announces the contact point(s) of the NGN service stratum components to the EUE (described in clause 6.2 of [ITU-T Y.2014]). The same functionalities are now supported in the evolved NGN via two individual high-level functions, NASSF and NASSsupportF. The functionalities supported by NASSF and NASSsupportF are described in clauses 9.1 and 9.2. + +### 9.1 Network attachment signalling service function + +NASSF is considered an internal network application (service) and interacts with EUE through a session established between the NASSF and EUE. This session is established with the help of NASSsupportF prior to providing network attachment service. Other than EUE, NASSF also interacts with ASFs and SSFs (e.g., NASSsupportF) in the service stratum. The functionalities of NASSF are as follows: + +#### a) Registration Support + +The NASSF provides registration at the access level and initialization of EUE for accessing NGN services (per clause 7.1.2.2 of [ITU-T Y.2012]). + +#### b) IP address allocation + +The NASSF is responsible for the IP address allocation to the EUE. It may be able to allocate two kinds of IP addresses, a persistent IP address and a temporary IP address, to the EUE, in order to + +support mobility (per clause 7.2.1 of [ITU-T Y.2014]). It supports IP address allocation for both the host-based and network-based mobility cases. + +#### c) Authorization and authentication + +The NASSF performs user authentication, as well as authorization checking, based on transport subscription profiles, for network access (per clause 9.3.2.2 of [ITU-T Y.2012]). It also contains subscription authentication data (transport subscriber identifier, list of supported authentication methods, etc.) and information related to the required network access configuration: this data is called "transport subscription profile" for end users (per clause 9.3.2.3 of [ITU-T Y.2012]). + +#### d) Association between the IP address and EUE location information + +The NASSF registers the association between the IP address allocated to the EUE and the related network location information, e.g., access transport equipment characteristics, logical connection identifier, identification of the edge policy enforcement device, etc. (based on clause 9.3.2.4 of [ITU-T Y.2012]). It also responds to location queries from other functions (described in clause 7.2.3 of [ITU-T Y.2014]). + +#### e) Distribution of network configuration parameters + +The NASSF can optionally distribute network configuration parameters, such as address of domain name system (DNS) server(s), address of signalling proxies for specific service stratum components to EUE (per clause 9.3.2.1 of [ITU-T Y.2012]). However, it may have to collect some access network related configuration parameters via NASSsupportF. + +#### f) Initialization and update of the home gateway + +The NASSF is used during initialization and update of the home gateway (HGW). It provides the HGW with additional configuration information (e.g., configuration of a firewall internally in the HGW, quality of service (QoS) marking of IP packets, etc.). These data differ from the network configuration data (based on clause 9.3.2.6 of [ITU-T Y.2012]). + +#### g) Session initiation with EUE through NASSsupportF + +A session needs to be established between EUE and NASSF for signalling related to the network attachment service. The NASSF initiates a session establishment request via NASSsupportF for the same. + +### 9.2 Network attachment signalling service support function (NASSsupportF) + +NASSsupportF interacts with the RACFs (transport control functions) for resource allocation and admission control, and to provide relevant information for the network attachment service. The NASSsupportF also interacts with the signalling service functions in the application layer to provide support for network attachment service. Functionalities of the NASSsupportF are as follows: + +#### a) Support for session establishment between EUE and NASSF: + +The NASSsupportF requests the RACFs to configure resources in transport functions for a signalling session between the EUE and NASSF. + +#### b) The NASSsupportF collects and provides the EUE access network information to NASSF. This information uniquely identifies the access network to which the EUE is attached. (described in clause 7.2.1 of [ITU-T Y.2014]) + +#### c) The NASSsupportF can optionally perform the collection of accounting data for each user authenticated by the NASSF. + +# 10 High-level functions for mobility service in evolved NGN + +In an existing NGN, the MMCF is divided into two major functionalities: EUE location management and handover control. The handover control functions (HCFs) are used to provide session continuity + +for ongoing sessions of the moving EUE. The same functionalities are now supported in the evolved NGN via two individual high-level functions, MSSF and MSSsupportF. The functionalities supported by the MSSF and MSSsupportF are described in clauses 10.1 and 10.2. + +### **10.1 Mobility signalling service function** + +The MSSF interacts with the EUE through a session established between the MSSF and EUE. This session is established through the MSSsupportF prior to providing a mobility service. MSSF also interacts with ASFs and SSFs (e.g., MSSsupportF) in the service stratum. The functionalities of the MSSF are as follows: + +#### **a) Location management** + +The MSSF initiates location registration on behalf of the EUE in the case of network-based mobility. It also processes location registration messages sent from or on behalf of the EUE. The MSSF manages the binding between the persistent IP address assigned to the EUE and its temporary address, in the case of host-based mobility, or the address of the lower tunnel-end point, in the case of network-based mobility (described in clause 9.3.2.9 of [ITU-T Y.2012]). Optionally, it holds two location bindings for the mobile EUE by marking the binding for the serving network as active state and marking the binding for the target network as standby state. MSSF is also responsible for the indication of a new mobility location binding and distribution of binding information to the MSSsupportF (clause 9.3.2 of [ITU-T Y.2012]). + +#### **b) Handover Signalling** + +The MSSF receives a list of candidate access links for handover from the EUE and sends them to the MSSsupportF for QoS verification. In a case where the EUE makes the handover decision, the MSSF provides the acceptable subset of links to the EUE. Before providing this to the EUE, the MSSF confirms this list from the RACFs through the MSSsupportF. In the case of network-triggered handover, it receives and forwards a handover request from the EUE to the MSSsupportF to trigger handover (described in clause 6.4.2.1 of [ITU-T Y.2018]). + +#### **c) Mobility service authentication and authorization** + +The MSSF handles user authentication, as well as authorization, for the mobility service in coordination with NASSF. EUE indicates mobility service request in its network attachment request. EUE may also indicate support for host-based and/or network-based mobility in this request. + +#### **d) Session initiation with EUE through the MSSsupportF** + +A session needs to be established between EUE and MSSF for signalling related to mobility service. MSSF initiates a session establishment request via the MSSsupportF for the same session establishment. + +## **10.2 Mobility signalling service support function (MSSsupportF)** + +MSSsupportF interacts with the RACFs (transport control functions) for resource configuration and to distribute relevant information for mobility service. The MSSsupportF also interacts with other signalling service functions in the application layer. The functionalities of MSSsupportF are as follows: + +#### **a) Handover decision** + +The handover decision is made by the MSSsupportF in case of network-based mobility upon receiving handover request from EUE. Besides, the handover decision is taken by EUE in a case of host-based mobility. + +#### **b) Resource configuration request to the RACFs** + +The MSSsupportF is responsible for requesting the RACFs for resource configuration based on handover decision that includes the following functionalities: + +- i) Based on received list of candidate access links for handover from MSSF, the MSSsupportF invokes the RACF to verify session QoS availability for each candidate access link for handover and inform the MSSF for communicating to the EUE; +- ii) It requests RACFs to re-provision the resource and QoS for the sessions of the moved EUE by submitting binding information to the RACFs; and +- iii) It also requests the RACFs to release resource and QoS for the data path, which is verified not to be used any longer (based on clause 6.4.2.1 of [ITU-T Y.2018]). + +In addition to the above, the MSSsupportF requests RACFs to configure resources in transport functions for a signalling session between EUE and MSSF. + +- c) Handover information distribution + +the MSSsupportF distributes a handover policy (to EUE via the MSSF in case of host-based mobility), which is a set of operator-defined rules and preferences that affect the handover decisions. It also distributes other information available in its network information repository (see clause 9.3.2.11 of [ITU-T Y.2012]) + +- d) Provisioning for network information repository + +The MSSsupportF contains a network information repository that provides static information on neighbouring networks to assist the access network discovery and selection decision. It also provides operator policies such as charging mode and rates (cost for the usage of the network), roaming agreements and mobility mechanism selection policies (based on clause 6.4.3.1 of [ITU-T Y.2018]). + +# **11 General procedures for network attachment** + +Clauses 11.1 and 11.2 cover general procedures for network attachment that comprise registration and session establishment. Registration is the responsibility of the NASSF in the recommended architecture, which is completed with the help of the NASSsupportF. The session establishment procedure is required to establish a data path through NGN to provide a service to EUE. It is also required to establish a signalling path with the EUE for built-in services. + +## **11.1 Registration procedure** + +The registration procedure is required to authenticate and authorize the EUE for availing network services. It also includes EUE context creation, functional entities selection and policy association for that particular EUE in the network. Information flow for EUE registration (Figure 11-1) is as follows: + +- a) EUE sends a 'registration request' message to the access relay functional entity (AR-FE) (description available in clause 7.2.7 of [ITU-T Y.2014]) in the access network indicating service requests, its identity, credentials and attributes required for authentication and authorization. + +NOTE – The EUE sends the initial registration request using the preconfigured common (or default) path (channel) to communicate with the AR-FE for the first time. The consequent signalling exchange between the EUE and AR-FE are handled through a dedicated path set up for the purpose. + +- b) AR-FE forwards this request to the NASSF. The NASSF performs authentication, authorization and confirms the EUE identity and allowed services. After successful authentication and authorization, it initiates EUE registration and forwards the 'registration request' along with user profile and list of authorized services to NASSsupportF, which selects functional entities (in the service stratum and transport stratum) and associates them with the EUE. Furthermore, it creates EUE context and performs policy association. After + +completion of these associations, the NASSsupportF sends a registration response to the NASSF. The NASSF sends a 'registration accept' to the EUE. + +![Sequence diagram showing the information flow for EUE registration between EUE, AR-FE, NASSF, and NASSsupportF.](812e188283162af0b54fb3e30ffee51b_img.jpg) + +``` + +sequenceDiagram + participant EUE + participant AR-FE + participant NASSF + participant NASSsupportF + + EUE->>AR-FE: Registration request + AR-FE->>NASSF: Registration request + Note over NASSF: Authorization, authentication and registration initiation + NASSF->>NASSsupportF: Registration request with 'user profile' + Note over NASSsupportF: Functional entities selection and policy association + NASSsupportF->>NASSF: Registration response + NASSF->>AR-FE: Registration accept + AR-FE->>EUE: Registration accept + Note over AR-FE: Registration + +``` + +The diagram illustrates the registration process. It starts with the EUE sending a 'Registration request' to the AR-FE. The AR-FE then forwards this request to the NASSF. The NASSF performs 'Authorization, authentication and registration initiation' before sending a 'Registration request with 'user profile'' to the NASSsupportF. The NASSsupportF handles 'Functional entities selection and policy association' and sends a 'Registration response' back to the NASSF. The NASSF then sends a 'Registration accept' message to the AR-FE, which finally sends a 'Registration accept' to the EUE. A dashed line at the bottom indicates the end of the registration phase, with the label 'Registration' below it. + +Sequence diagram showing the information flow for EUE registration between EUE, AR-FE, NASSF, and NASSsupportF. + +**Figure 11-1 – Information flow for EUE registration** + +## 11.2 Session establishment procedure + +The session establishment procedure is the same for data sessions and also for all built-in service functions, i.e., for the establishment of a signalling session between EUE and different signalling service functions (for example NASSF or MSSF). Hence, the generic terms, signalling service function (SigSF) and signalling service support function (SSsupportF) are used in this clause. + +NOTE 1 – It is assumed that the EUE sending session establishment request has a default path available for signalling exchange and, it (EUE) is already registered with NGN, and authorized with the built-in service it is requesting session establishment for, i.e., with the signalling service function of that service. + +The information flow for session establishment (Figure 11-2) is as follows: + +- a) The EUE sends the 'session establishment request' message to the AR-FE in the access network indicating its identity and with a request for data path. + +NOTE 2 – The EUE sends the initial session establishment request using the preconfigured default path to communicate with the AR-FE for the first time. The consequent signalling exchange between the EUE and AR-FE is handled through a dedicated path set up for the purpose. + +NOTE 3 – It is also possible that the network itself initiates the session establishment for signalling as a result of registration instead of EUE initiating. + +- b) AR-FE forwards this request to the SigSF. The SigSF performs authentication and authorization for the requested service and sends session establishment request to the SSsupportF. Further, the SSsupportF sends the request to the RACFs for resource configuration for data path establishment. After receiving session establishment response from the RACFs, SSsupportF sends a response to the SigSF. Further, the SigSF sends a 'session establishment complete' message to the EUE via the AR-FE. + +![Sequence diagram showing information flow for session establishment between EUE, AR-FE, SigSF, SSsupportF, and RACF.](e69b9188aa2c14ec6b21c83f711fef65_img.jpg) + +``` + +sequenceDiagram + participant EUE + participant ARFE as AR-FE + participant SigSF + participant SSsupportF as SSsupportF + participant RACF + + EUE->>ARFE: Session establishment request + ARFE->>SigSF: Session establishment request + Note over SigSF: Authentication and authorization for requested service + SigSF->>SSsupportF: Session establishment request + SSsupportF->>RACF: Session establishment request + Note over RACF: Resource configuration for establishing session + RACF->>SSsupportF: Session establishment response + SSsupportF->>SigSF: Session establishment response + SigSF->>ARFE: Session establishment complete + ARFE->>EUE: Session establishment complete + +``` + +The diagram illustrates the session establishment process across five entities: EUE, AR-FE, SigSF, SSsupportF, and RACF. The process begins with a 'Session establishment request' from EUE to AR-FE, which then forwards it to SigSF. SigSF performs 'Authentication and authorization for requested service' before sending the request to SSsupportF. SSsupportF then sends the request to RACF, where 'Resource configuration for establishing session' occurs. RACF returns a 'Session establishment response' to SSsupportF, which is then passed back to SigSF. Finally, SigSF sends a 'Session establishment complete' message to AR-FE, which in turn sends the same message to EUE. The diagram is divided into two sections by dashed lines, with the label 'Session establishment' appearing in both. + +Sequence diagram showing information flow for session establishment between EUE, AR-FE, SigSF, SSsupportF, and RACF. + +Y.2325(23) + +**Figure 11-2 – Information flow for session establishment** + +# Appendix I + +(This appendix does not form an integral part of this Recommendation.) + +## **A.I Network attachment procedure with mobility service (in case of host-based mobility)** + +The following information flow is for the network attachment procedure, which includes registration, session establishment and location update in case of host-based mobility. Reference for signalling flows and their description is taken from clause 7.2.1 of [ITU-T Y.2018] and mapped per recommended functions in this Recommendation. + +Figure I.1 shows the information flow for the network attachment procedure with mobility service, which is divided into three phases: authentication and authorization (registration), IP configuration (session establishment) and mobility location management. + +### *Phase 1: Authentication and authorization (registration)* + +The EUE sends an attachment request to the NASSF in which it also indicates that it requires mobility services along with the indication of support for host-based mobility. The NASSF performs authentication and authorization of the EUE, along with updating the relevant EUE profile information. EUE receives the response related to mobility services when the EUE authentication is successful and it is authorized to use the network resources. NASSF also transfers a EUE profile update to NASSsupportF along with mobility service-related information. + +NOTE – This phase may be optional as EUE can be pre-authenticated and pre-authorized to receive mobility service. + +### *Phase 2: IP configuration (session establishment)* + +The EUE sends an IP configuration request to the NASSF for the dynamic provisioning of IP address and IP configuration information in case of host-based mobility. The NASSF allocates the IP address and establishes the mapping between the allocated IP address and the logical connection identifier. This mapping information is correlated with transport subscription profile. The NASSF sends a resource configuration request along with additional correlated information to the NASSsupportF, and NASSsupportF forwards the configuration request with correlated information to the RACF. + +The RACF configures resources and updates the EUE related profile information and sends the configuration response back to the NASSsupportF. + +The NASSsupportF also informs the MSSF of the host-based mobility information, along with the user identity and network selection key transfer function. + +The NASSsupportF then sends a configuration response to the NASSF for communication with the EUE. + +The NASSF sends the required configuration information (e.g., persistent IP address, host-based mobility is to be used indication) to the EUE. + +### *Phase 3: Mobility location management* + +The EUE initiates the mobility location binding update/registration to the MSSF. + +MSSF updates its mobility bindings information and responds back to the EUE with the mobility location binding acknowledgement. + +![Sequence diagram showing information flows for attachment, case of host-based mobility, between EUE, NASSF, NASSsupportF, RACF, and MSSF.](c5452f95f3b28f1bfe29e84fbc2e1267_img.jpg) + +``` + +sequenceDiagram + participant EUE + participant NASSF + participant NASSsupportF + participant RACF + participant MSSF + + Note over EUE, NASSF: Authentication and authorization (Registration) + EUE->>NASSF: Attachment (Registration) request with mobility service + Note over NASSF: Authentication, authorization, profile update + NASSF-->>EUE: Response for mobility services + NASSF->>NASSsupportF: EUE profile update + Note over NASSF, NASSsupportF: Authentication and authorization + + Note over EUE, NASSF: IP configuration (Session establishment) + EUE->>NASSF: IP configuration (Session establishment) request in case of host-based mobility + Note over NASSF: IP configuration allocation, mapping of IP configuration with logical identifier and correlates mapping information with transport profile + NASSF->>NASSsupportF: Configuration request with correlated info + NASSsupportF->>RACF: Configuration request with correlated info + RACF-->>NASSsupportF: Configuration response + NASSsupportF->>MSSF: Indication of host-based mobility with user identity and network selection key transfer function + NASSsupportF-->>NASSF: Configuration response + NASSF-->>EUE: Configuration response + + Note over EUE, NASSF: IP configuration + Note over EUE, NASSF: Mobility location management + Note over EUE, NASSF: Mobility location binding update + NASSF->>MSSF: Mobility location binding registration/update + Note over MSSF: Mobility location binding registration/update + MSSF-->>EUE: Mobility location binding acknowledgement + Note over EUE, NASSF: Mobility location management + +``` + +The diagram illustrates the information flows for attachment in the case of host-based mobility across five entities: EUE, NASSF, NASSsupportF, RACF, and MSSF. The process is divided into several phases indicated by dashed lines: + +- Authentication and authorization (Registration):** EUE sends an "Attachment (Registration) request with mobility service" to NASSF. NASSF performs "Authentication, authorization, profile update" and sends a "Response for mobility services" back to EUE. NASSF then sends an "EUE profile update" to NASSsupportF, which performs "Authentication and authorization". +- IP configuration (Session establishment):** EUE sends an "IP configuration (Session establishment) request in case of host-based mobility" to NASSF. NASSF performs "IP configuration allocation, mapping of IP configuration with logical identifier and correlates mapping information with transport profile". It then sends a "Configuration request with correlated info" to NASSsupportF, which forwards it to RACF. RACF returns a "Configuration response" to NASSsupportF. NASSsupportF sends an "Indication of host-based mobility with user identity and network selection key transfer function" to MSSF and a "Configuration response" back to NASSF. NASSF then sends a "Configuration response" back to EUE. +- IP configuration:** This phase is indicated by a dashed line. +- Mobility location management:** NASSF sends a "Mobility location binding update" to MSSF. MSSF performs "Mobility location binding registration/update". +- Mobility location binding acknowledgement:** MSSF sends a "Mobility location binding acknowledgement" back to EUE. +- Mobility location management:** The final phase indicated by a dashed line. + +Sequence diagram showing information flows for attachment, case of host-based mobility, between EUE, NASSF, NASSsupportF, RACF, and MSSF. + +Y.2325(23) + +**Figure I.1 – Information flows for attachment, case of host-based mobility** + +# Bibliography + +- [b-ITU-T M.3050.1] Recommendation ITU-T M.3050.1 (2007), *Enhanced Telecom Operations Map (eTOM) – The business process framework*. +- [b-ITU-T Q.1706] Recommendation ITU-T Q.1706/Y.2801 (2006), *Mobility management requirements for NGN*. + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/Y/T-REC-Y.2346-202312-I_PDF-E/raw.md b/marked/Y/T-REC-Y.2346-202312-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..49355e22292659e04f8c0dc0664856d655c7fe54 --- /dev/null +++ b/marked/Y/T-REC-Y.2346-202312-I_PDF-E/raw.md @@ -0,0 +1,476 @@ + + +# Recommendation + +## ITU-T Y.2346 (12/2023) + +SERIES Y: Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities + +Next Generation Networks – Enhancements to NGN + +--- + +## **Requirements and framework of service function orchestration based on service function chaining** + +## ITU-T Y-SERIES RECOMMENDATIONS + +### Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities + +| | | +|-------------------------------------------------------------------|----------------------| +| GLOBAL INFORMATION INFRASTRUCTURE | Y.100-Y.999 | +| INTERNET PROTOCOL ASPECTS | Y.1000-Y.1999 | +| NEXT GENERATION NETWORKS | Y.2000-Y.2999 | +| Frameworks and functional architecture models | Y.2000-Y.2099 | +| Quality of Service and performance | Y.2100-Y.2199 | +| Service aspects: Service capabilities and service architecture | Y.2200-Y.2249 | +| Service aspects: Interoperability of services and networks in NGN | Y.2250-Y.2299 | +| Enhancements to NGN | Y.2300-Y.2399 | +| Network management | Y.2400-Y.2499 | +| Computing power networks | Y.2500-Y.2599 | +| Packet-based Networks | Y.2600-Y.2699 | +| Security | Y.2700-Y.2799 | +| Generalized mobility | Y.2800-Y.2899 | +| Carrier grade open environment | Y.2900-Y.2999 | +| FUTURE NETWORKS | Y.3000-Y.3499 | +| CLOUD COMPUTING | Y.3500-Y.3599 | +| BIG DATA | Y.3600-Y.3799 | +| QUANTUM KEY DISTRIBUTION NETWORKS | Y.3800-Y.3999 | +| INTERNET OF THINGS AND SMART CITIES AND COMMUNITIES | Y.4000-Y.4999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T Y.2346 + +## Requirements and framework of service function orchestration based on service function chaining + +## Summary + +Recommendation ITU-T Y.2346 provides scenarios, requirements, and framework of service function orchestration based on service function chaining. Based on user requirements, service function orchestration can realize function services deployment and dynamically adjustment on demand, and based on resource situation, it can realize resource optimization and load balance of service functions. + +## History \* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T Y.2346 | 2023-12-14 | 13 | 11.1002/1000/15733 | + +## Keywords + +Architecture, framework, service function chaining, service function orchestration. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2024 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|---------------------------------------------------------------------------------|-------------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 1 | +| 4 Abbreviations and acronyms ..... | 1 | +| 5 Conventions ..... | 2 | +| 6 Background and motivations ..... | 2 | +| 7 Scenarios..... | 3 | +| 7.1 SFC solution based on service function orchestration ..... | 3 | +| 7.2 SFC solution based on performance request ..... | 3 | +| 8 General framework of service function orchestration based on SFC ..... | 4 | +| 9 Requirements of service function orchestration based on SFC ..... | 5 | +| 9.1 Requirements of service function management ..... | 5 | +| 9.2 Requirements of service function orchestration ..... | 6 | +| 10 Functional architecture of service function orchestration based on SFC ..... | 6 | +| 10.1 Service layer ..... | 6 | +| 10.2 Service function orchestration layer ..... | 7 | +| 10.3 Control layer ..... | 8 | +| 10.4 Infrastructure layer ..... | 8 | +| 11 Workflow of service function orchestration based on SFC ..... | 9 | +| 11.1 Procedure for implementation of service function chaining ..... | 9 | +| 11.2 Procedure for service function orchestration..... | 10 | +| 12 Security considerations..... | 11 | +| Bibliography..... | 12 | + + + +# Recommendation ITU-T Y.2346 + +## Requirements and framework of service function orchestration based on service function chaining + +# 1 Scope + +This Recommendation provides scenarios, requirements, and framework of service function orchestration based on service function chaining. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- [ITU-T Y.2323] Recommendation ITU-T Y.2323 (2018), *Requirements and capabilities of orchestration in next generation network evolution*. +- [ITU-T Y.2324] Recommendation ITU-T Y.2324 (2019), *Functional architecture of orchestration in next generation network evolution (NGNe)*. +- [ITU-T Y.2501] Recommendation ITU-T Y.2501(2021), *Computing power network – Framework and architecture*. + +# 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 service function** [b-IETF RFC 7665]: A function that is responsible for the specific treatment of received packets. As a logical component, a service function can be realized as a virtual element or be embedded in a physical network element. One or more service functions can be involved in the delivery of added-value services. A non-exhaustive list of abstract service functions includes firewalls, wide area network (WAN) and application acceleration, deep packet inspection (DPI), lawful intercept (LI), server load balancing, and so on. + +**3.1.2 SFC (service function chaining)** [b-IETF RFC 7665]: SFC is used to describe the definition and instantiation of an ordered list of instances of such service functions, and the subsequent "steering" of traffic flows through those service functions. + +### 3.2 Terms defined in this Recommendation + +None. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +- API Application Programming Interface +- ASP Application Service Provider + +| | | +|------|-------------------------------| +| BSS | Business Support System | +| CPE | Customer Premise Equipment | +| CSP | Cloud Service Provider | +| DDoS | Distributed Denial of Service | +| ISP | Internet Service Provider | +| MEC | Mobile Edge Computing | +| OSS | Operation Support System | +| SFC | Service Function Chaining | +| VMS | Virtual Management System | +| VNF | Virtualized Network Function | +| WAN | Wide Area Network | + +## 5 Conventions + +In this Recommendation: + +The keywords "is required to" indicate a requirement which must be strictly followed and from which no deviation is permitted, if conformance to this Recommendation is to be claimed. + +The keywords "is recommended" indicate a requirement which is recommended but which is not absolutely required. Thus, this requirement need not be present to claim conformance. + +# 6 Background and motivations + +From the trend evolution of ubiquitously distributed cloud, edge and terminal, the new generation of network is transforming from the network infrastructure with information transmission as the core to the intelligent cloud network infrastructure with integrated computing, storage and network resources. + +With the development of network and services, more and more value-added functions need to be deployed on demand. Originally, a variety of service functions could be deployed in the centralized cloud resource pool. With the development of mobile edge computing (MEC) technology, and the requirements of network performance such as network quality and request delay, as well as the increasing demand for flexible addition and reduction of service functions, operators will deploy service functions on the edge nodes. Service functions deployed in the edge nodes are connected in series to meet users' demand for flexible scheduling of service functions and to achieve response time minimization, resource optimization, and high network efficiency. + +The existing service function chaining (SFC) is a set of virtualized network functions (VNFs) executed in a specific order to provide traffic flow control. By the use of SFC, cloud service providers (CSPs), application service providers (ASPs), and Internet service providers (ISPs) can offer personalized services to their customers more easily. + +In [ITU-T Y.2323] and [ITU-T Y.2324], an NGN evolutionary architecture with orchestration has been described thoroughly where the network resource could be optimized, and innovative services could be realized via a unified orchestration. In [ITU-T Y.2501], an NGN evolutionary architecture can provide optimal scheduling of computing, storage, and network resources. As the number of service functions of an SFC grows, there are many challenges that should be addressed. Management of the SFCs manually will be a complex task, and the optimal placement of them will be hard. As a result, to overcome these challenges, the service function orchestration based on an SFC is required. + +### 7.1 SFC solution based on service function orchestration + +Taking security protection as an example, enterprise users need service functions of firewall and anti-distributed denial of service (DDoS) attacks, and operators are required to flexibly divert traffic to the corresponding security resource pool to realize providing these service functions on demand. + +Taking the private line service scenario as another example, providers connect cloud resource pools through a network in which different service functions are deployed. Oriented by user service demand, serial service functions deployed in multi-clouds need to be provided through the network. However, the same service function may be deployed in different cloud resource pools. Therefore, it is necessary to realize service functions orchestrating based on SFC to solve the problems, such as how to select an appropriate resource pool, how to dynamically adjust service functions, how to realize service scheduling, and so on. + +![Figure 7-1: SFC solution based on service function orchestration. The diagram shows a network topology with four cloud resource pools and a central network of routers and customer premise equipment (CPE). Cloud resource pool 1 contains Function1 and Function3. Cloud resource pool 2 contains Function2 and Function3. Cloud resource pool 3 contains Function1 and Function4. Cloud resource pool 4 contains Function2 and Function4. The network consists of routers R1 through R9. CPE1 is connected to R1, CPE2 to R5, and CPE3 to R4. An orange line represents a service function chain starting from CPE1, passing through R1, R2, R6, R7, R9, and R4 to reach CPE3. Additionally, orange lines show service function chaining from R2 to Function1 in Cloud resource pool 1, then to Function3 in Cloud resource pool 2, and finally to Function4 in Cloud resource pool 4.](7a0db9703b68b3d06cdaeefc084c0006_img.jpg) + +Figure 7-1: SFC solution based on service function orchestration. The diagram shows a network topology with four cloud resource pools and a central network of routers and customer premise equipment (CPE). Cloud resource pool 1 contains Function1 and Function3. Cloud resource pool 2 contains Function2 and Function3. Cloud resource pool 3 contains Function1 and Function4. Cloud resource pool 4 contains Function2 and Function4. The network consists of routers R1 through R9. CPE1 is connected to R1, CPE2 to R5, and CPE3 to R4. An orange line represents a service function chain starting from CPE1, passing through R1, R2, R6, R7, R9, and R4 to reach CPE3. Additionally, orange lines show service function chaining from R2 to Function1 in Cloud resource pool 1, then to Function3 in Cloud resource pool 2, and finally to Function4 in Cloud resource pool 4. + +**Figure 7-1 – SFC solution based on service function orchestration** + +When a user requests to establish a private connection from a customer premise equipment (CPE1) to CPE3 and access services Function1, Function3, and Function4, a service function chaining needs to be generated to connect these service functions in appropriate series. As shown in Figure 7-1, Function1 is deployed in both cloud resource pool 1 and cloud resource pool 3, and Function3 is deployed in both cloud resource pool 1 and cloud resource pool 2. When network providers make decisions on which cloud resource pools need to be selected to provide service functions, it is necessary to consider network quality, delay and other factors in order to realize service function orchestration. + +### 7.2 SFC solution based on performance request + +In the video surveillance scenario, the traditional way is to capture various information through the video surveillance system and then send the information to the processing server for valuable information extraction. However, this method will transmit a large amount of video data from the video surveillance system to the processing server, which may increase the traffic load of the network and lead to high network delay. Combined with MEC technology, data analysis can be carried out directly on the MEC enabled node which is very close to the video surveillance system. At the same + +time, combined with the scheduling of computing, storage, and network resources, when the service request increases sharply, it can be switched to other MEC enabled node to realize data analysis. + +Therefore, in this scenario, we may split these service functions into sub-service functions and select appropriate resource pools in combination with the computing, storage, and network resources to fulfil the orchestration of sub-service functions and generate a service function chaining to connect these sub-service functions in series. + +As shown in Figure 7-2, when the user access Function1, and the service function can be split into sub-service functions Function1.1, Function1.2 and Function1.3, network providers deploy corresponding service functions in appropriate resource pools based on the computing and storage resources, and then connect them in series to generate service function chaining based on the performance request. + +![Figure 7-2: SFC solution based on performance request. The diagram illustrates a service function chaining (SFC) architecture. On the left, 'Function1' is decomposed into three sub-functions: 'Function1.1', 'Function1.2', and 'Function1.3'. These are connected in a vertical sequence. The network topology consists of a central horizontal chain of routers: CPE1 - R1 - R2 - R3 - R4 - CPE3. Below this chain, there are additional routers: CPE2 - R5 - R6 - R7 - R9. Four cloud resource pools are shown: 'Cloud resource pool 1' (containing 'Function1.1'), 'Cloud resource pool 2' (containing 'Computing power'), 'Cloud resource pool 3' (containing 'Function1.2'), and 'Cloud resource pool 4' (containing 'Function1.3'). Orange lines indicate the service function chaining path: from CPE1 to R1, then to R2 (which connects to 'Function1.1' in Cloud resource pool 1), then to R3 (which connects to 'Function1.2' in Cloud resource pool 3), then to R4 (which connects to 'Function1.3' in Cloud resource pool 4), and finally to CPE3. The label 'Y.2346(23)' is located at the bottom right of the diagram.](e6df2733626a85205c1db682e6259c46_img.jpg) + +Figure 7-2: SFC solution based on performance request. The diagram illustrates a service function chaining (SFC) architecture. On the left, 'Function1' is decomposed into three sub-functions: 'Function1.1', 'Function1.2', and 'Function1.3'. These are connected in a vertical sequence. The network topology consists of a central horizontal chain of routers: CPE1 - R1 - R2 - R3 - R4 - CPE3. Below this chain, there are additional routers: CPE2 - R5 - R6 - R7 - R9. Four cloud resource pools are shown: 'Cloud resource pool 1' (containing 'Function1.1'), 'Cloud resource pool 2' (containing 'Computing power'), 'Cloud resource pool 3' (containing 'Function1.2'), and 'Cloud resource pool 4' (containing 'Function1.3'). Orange lines indicate the service function chaining path: from CPE1 to R1, then to R2 (which connects to 'Function1.1' in Cloud resource pool 1), then to R3 (which connects to 'Function1.2' in Cloud resource pool 3), then to R4 (which connects to 'Function1.3' in Cloud resource pool 4), and finally to CPE3. The label 'Y.2346(23)' is located at the bottom right of the diagram. + +**Figure 7-2 – SFC solution based on performance request** + +## 8 General framework of service function orchestration based on SFC + +The framework of service function orchestration in a computing power network includes the service layer, service function orchestration layer, control layer and infrastructure layer. The service function orchestration framework is shown in Figure 8-1. + +![Figure 8-1 – Service function orchestration framework diagram. The diagram is divided into four horizontal layers: Service layer, Service function orchestration layer, Control layer, and Infrastructure layer. In the Service layer, 'Users' and 'Service function providers' interact with an 'External open function' (represented by a circular arrow icon). The Service function orchestration layer contains 'Service function management' and 'Service function orchestration' blocks. The Control layer contains a 'Control layer' block with three circular icons. The Infrastructure layer shows an 'Operator network' (a dashed blue oval with server icons) and 'Resource pools' (dashed red ovals with server icons). 'Function1' and 'Function2' are shown in the left resource pool, 'Function2' and 'Function3' in the right, and 'Function3' and 'Function4' in the rightmost. Arrows indicate data flow from Users and Service function providers to the External open function, then to Service function management, then to Service function orchestration, then to the Control layer, and finally to the Infrastructure layer.](cfef993dcc8fb513de79eb1f93cf26ae_img.jpg) + +Figure 8-1 – Service function orchestration framework diagram. The diagram is divided into four horizontal layers: Service layer, Service function orchestration layer, Control layer, and Infrastructure layer. In the Service layer, 'Users' and 'Service function providers' interact with an 'External open function' (represented by a circular arrow icon). The Service function orchestration layer contains 'Service function management' and 'Service function orchestration' blocks. The Control layer contains a 'Control layer' block with three circular icons. The Infrastructure layer shows an 'Operator network' (a dashed blue oval with server icons) and 'Resource pools' (dashed red ovals with server icons). 'Function1' and 'Function2' are shown in the left resource pool, 'Function2' and 'Function3' in the right, and 'Function3' and 'Function4' in the rightmost. Arrows indicate data flow from Users and Service function providers to the External open function, then to Service function management, then to Service function orchestration, then to the Control layer, and finally to the Infrastructure layer. + +**Figure 8-1 – Service function orchestration framework** + +**Service layer:** includes users, service function providers and openness function; specifically, users are individuals or enterprises who request service functions to be accessed based on their own requirements for service function sequence, network, computing and storage resources. Service function providers refer to providers who can provide service functions deployed in the operator's own resource pool or provided by a third-party cloud provider. Openness function is exposed to external parties to realize traffic statistics, billing, demonstration and other purposes. + +**Service function orchestration layer:** responsible for service function orchestration, obtains service requirement information from users to achieve service function orchestration, and sends orchestration results to the control layer to generate SFC configuration based on the routing policies. + +**Control layer:** collects network and cloud resource topology information, performs information announcements, makes routing decisions based on orchestration results from the service function orchestration layer, and sends the SFC configuration information to the infrastructure layer. + +**Infrastructure layer:** includes network infrastructure and cloud infrastructure which provide service functions connected with the network infrastructure. + +## 9 Requirements of service function orchestration based on SFC + +### 9.1 Requirements of service function management + +Service function management is required to support management features that include the following aspects: + +- Service function registration, including the registration of deployed service functions; +- Service function deployment, including deploying new service functions based on service requests or other information; +- Service function optimization, to optimize the deployed service functions to achieve high network efficiency. + +### 9.2 Requirements of service function orchestration + +Service function orchestration is required to support orchestration features that include the following aspects: + +- Service function splitting for service functions, reasonably splits them into appropriate sub-service functions which can be allocated to appropriate nodes for processing; + - Service function ordering based on the implementation mechanism of SFC, divides the service functions into serial processing mode, and parallel processing mode; +- NOTE – Serial processing mode refers to accessing the service functions one by one in order. Parallel processing mode means that when service functions share no dependency, they can work in parallel. +- Service function selection is based on user requirements and a comprehensive consideration of computing resources, storage resources, and network resources to select the appropriate resource pools. + +## 10 Functional architecture of service function orchestration based on SFC + +The functional architecture of service function orchestration based on SFC is depicted in Figure 10-1. It consists of four layers that provide the aforementioned functionalities by interacting with each other. + +![Functional architecture of service function orchestration based on SFC diagram](7f17c430b9598e4d748a8041457810b3_img.jpg) + +The diagram illustrates the functional architecture of service function orchestration based on SFC, organized into four distinct layers, each enclosed in a rectangular box. The layers are stacked vertically and connected by double-headed blue arrows, indicating bidirectional interaction. + +- Service layer**: The top layer, containing three rounded rectangular boxes: "Openness function", "User profile function", and "Service profile function". +- Service function orchestration layer**: The second layer, containing two large rounded rectangular boxes. The left box is labeled "Service function management" and contains three smaller rounded rectangular boxes: "Registration function", "Deployment function", and "Optimization function". The right box is labeled "Service function orchestration" and contains four smaller rounded rectangular boxes: "Splitting function", "Ordering function", "Selection function", and "Orchestration function". +- Control layer**: The third layer, containing three rounded rectangular boxes: "Information announcement function", "Resource topology management function", and "Routing decision function". +- Infrastructure layer**: The bottom layer, containing two rounded rectangular boxes: "Network infrastructure" and "Cloud infrastructure". + +Y.2346(23) + +Functional architecture of service function orchestration based on SFC diagram + +**Figure 10-1 – Functional architecture of service function orchestration based on SFC** + +### 10.1 Service layer + +Service layer is responsible for managing user and service information, which is used to receive service function orchestration requirements, send service requirement information to the service function orchestration layer, and expose it to the external parties. + +Service layer has three basic functions: user profile function, service profile function, and openness function. + +- **User profile function:** responsible for user information management, including users who request services, enterprise users and individual users who provide service functions, and the administrator (operation and maintenance, management, etc.) to implement authentication, authorization, and permission management. After authentication and authorization, users can initiate service requests and the service providers can provide service functions. +- **Service profile function:** to obtain service requirement information from users, including service functions to be accessed, requirements for network resources, computing resources, and storage resources, and send the information to the service function orchestration layer. +- **Openness function:** expose to external parties to realize billing, demonstration, and other purposes. For the service transaction process, the openness function receives the service function orchestration results from the service function orchestration layer and sends the relevant information to the traffic statistics function and operator operation support system (OSS) / business support system (BSS), generates bills through the billing function, and sends it to the user profile function to confirm the relevant billing information. For data demonstration purpose, this function supports open application programming interface (API) for providing relevant data to a third party for demonstration. + +### 10.2 Service function orchestration layer + +Service function orchestration layer is responsible for service function orchestration, selection, and management. + +The service function orchestration layer has seven basic functions: registration function, deployment function, optimization function, splitting function, ordering function, selection function, and orchestration function. + +- **Registration function:** the function is responsible for registration of the service functions, identifying their locations and resource status. +- **Deployment function:** analysing the information from the user profile function and service profile function in order to meet service requests. The function is recommended to select the appropriate edge nodes to deploy service functions based on the user requests for frequently accessed services. +- **Optimization function:** from the perspective of network efficiency, the function enables the service functions which has not been accessed for a long time to be in sleep mode. For frequently selected service functions, the mechanism is recommended to set to reduce the problem of the increased fault rate caused by the long-time work. +- **Splitting function:** the function can split the service functions into several sub-service functions according to the service type that has been stored in the resource pool or according to the service task quantity, and stores and records its functional information including the order of service functions, service function characteristics and requirements for service functions and sub-service functions. +- **Ordering function:** the function is responsible for service functions and sub-service functions to realize ordering. Ordering is the index that indicates the sequence of each service function of an SFC, indicating whether a serial processing mode or a parallel processing mode is applied. And for serial processing mode, the pre-order relationship is required to be indicated. For parallel processing mode, there is no relevant pre-order relationship. +- **Selection function:** the function is responsible for resource pool selections for each service function and each sub-service function. The network requirements, computing resources and order sequences need to be considered at the same time, including bandwidth, delay, jitter, the load ratio of resource pools, computation requirements and so on. + +- **Orchestration function:** the function realizes service function orchestration based on the results of service function splitting function, service function ordering function and service function selection function. For a parallel processing mode, it is required to be consolidated on the specified node. + +### 10.3 Control layer + +The control layer collects resource information from the infrastructure layer and sends service function information to the service function orchestration layer for service function registration. The control layer receives the orchestration results from the service function orchestration function, making routing decisions, and sends the corresponding SFC configuration to the infrastructure layer. + +The control layer has three basic functions: information announcement function, resource topology management function, and routing decision function. + +- **Resource topology management function:** The function obtains network and cloud resource information from the infrastructure layer, abstracts the network topology, and is able to manage the lifecycle of the topology. In addition, it could obtain information on various hardware computing resources in the cloud infrastructure (including processors, memory, storage, etc.) and virtual systems such as virtual machines and containers after the virtualization of hardware computing resources, in order to provide service deployment environments for service functions. +- **Information announcement function:** The function confirms service function information of cloud infrastructure in the infrastructure layer based on the orchestration results from the service orchestration layer and announces it in the network topology. +- **Routing decision function:** The function performs route calculation and route selection, and sends the SFC configuration results to the infrastructure layer according to the synchronized information in the network. + +### 10.4 Infrastructure layer + +The infrastructure layer sends the resource information to the control layer and executes the corresponding SFC configuration based on the results of the control layer. + +Infrastructure layer includes network infrastructure and cloud infrastructure which provide service functions and establishes the network connection. + +- **Network infrastructure:** Network devices and the network topologies which provide forwarding capabilities for data packets, based on routers, switches and so on. +- **Cloud infrastructure:** Resource pools that provide deployment environments for service functions, the hardware of which is a server or server cluster consisting of processors, memory, storage, and so on, and the software of which is a generic or dedicated system such as virtual management system (VMS), container and so on. + +## 11 Workflow of service function orchestration based on SFC + +### 11.1 Procedure for implementation of service function chaining + +![Sequence diagram showing the information flow of an implementation of service function chaining across five layers: Users, Service layer, Service function orchestration layer, Control layer, and Infrastructure layer.](724c7777b608e53be38b12b6fb3c43bc_img.jpg) + +``` +sequenceDiagram + participant Users + participant Service_layer as Service layer + participant SFO_layer as Service function orchestration layer + participant Control_layer as Control layer + participant Infrastructure_layer as Infrastructure layer + + Users->>Service_layer: 1. Input service requirement + Service_layer->>SFO_layer: 2. Generate service function orchestration requirements + SFO_layer->>SFO_layer: 3. Analyse service functions to complete service function splitting and ordering + SFO_layer->>SFO_layer: 4. Perform service function selection and orchestration + SFO_layer->>Control_layer: 5. Policy and configuration instruction + Control_layer->>Infrastructure_layer: 6. Configuration result + Infrastructure_layer->>Control_layer: 7. Ack the configuration + Control_layer->>SFO_layer: 8. Ack the configuration completion + SFO_layer->>Service_layer: 9. Ack the configuration completion + Service_layer->>Service_layer: 10. Perform traffic statistic or other purposes + Service_layer->>Users: 11. Ack the configuration completion +``` + +Y.2346(23) + +Sequence diagram showing the information flow of an implementation of service function chaining across five layers: Users, Service layer, Service function orchestration layer, Control layer, and Infrastructure layer. + +**Figure 11-1 – Information flow of an implementation of service function chaining** + +The main steps for the implementation of service function chaining procedure are as follows by sequence: + +1. Users input the users' service requirement information; +2. Service layer receives the service requirement information including service functions to be accessed, requirements for network, computing and storage resources; +3. Service function orchestration layer analyses service functions, to split some service functions into several sub-service functions and to make the service functions and sub-service functions have appropriate order; +4. Based on service requirements for network, computing, and storage resources and service function ordering results, the service function orchestration layer selects the appropriate resource pools for each service functions and sub-service functions, and performs the service function orchestration; +5. Service function orchestration layer sends the policy and configuration instruction to the control layer; +6. Control layer sends the corresponding configuration result to the infrastructure layer; +7. Infrastructure layer sends the execution result to the control layer; +8. Control layer sends the execution result to the service function orchestration layer; +9. Service function orchestration layer sends the execution result to the service layer; + +10. Service layer sends the execution result to external parties to realize billing, demonstration, and other purposes; + +11. Service layer sends the execution result to users. + +### 11.2 Procedure for service function orchestration + +![Sequence diagram showing the information flow of service function orchestration between the Service layer, Service function orchestration layer, and Control layer.](1a827b10290f33d4fec04d0e8ef7a897_img.jpg) + +``` +sequenceDiagram + participant SL as Service layer + participant SFO as Service function orchestration layer + participant CL as Control layer + + SFO->>SL: 1. Input service requirement + activate SL + SL->>SFO: 2. Determine whether the service function can be splitted into several sub-service functions and split them into sub-service functions + deactivate SL + activate SFO + SFO->>SFO: 3. Send service requirement + deactivate SFO + activate SFO + SFO->>SFO: 4. Order the service functions to be accessed + deactivate SFO + activate SFO + SFO->>SFO: 5. Send ordering results and service requirement + deactivate SFO + activate SFO + SFO->>SFO: 6. Perform service function selection + deactivate SFO + activate SFO + SFO->>SFO: 7. Send selection results + deactivate SFO + activate SFO + SFO->>SFO: 8. Perform service function orchestration + deactivate SFO + activate SFO + SFO->>CL: 9. Policy and configuration + deactivate SFO + activate CL + CL->>SFO: 10. Ack the configuration completion + deactivate CL + activate SFO + SFO->>SL: 11. Ack the configuration completion + deactivate SFO + deactivate SL +``` + +The diagram illustrates the information flow of service function orchestration. It involves three main components: the Service layer, the Service function orchestration layer (which contains four sub-functions: splitting, ordering, selection, and orchestration), and the Control layer. The process follows 11 steps: 1. The Service layer sends an input service requirement to the splitting function. 2. The splitting function determines if the service can be split and performs the split. 3. The splitting function sends the service requirement to the ordering function. 4. The ordering function orders the service functions. 5. The ordering function sends ordering results and the service requirement to the selection function. 6. The selection function performs service function selection. 7. The selection function sends selection results to the orchestration function. 8. The orchestration function performs service function orchestration. 9. The orchestration function sends policy and configuration to the Control layer. 10. The Control layer acknowledges configuration completion to the orchestration function. 11. The orchestration function acknowledges configuration completion to the Service layer. + +Sequence diagram showing the information flow of service function orchestration between the Service layer, Service function orchestration layer, and Control layer. + +**Figure 11-2 – Information flow of service function orchestration** + +The main steps for the service function orchestration procedure are as follows by sequence: + +1. Service layer sends the service requirement information including service functions to be accessed, requirements for network, computing, and storage resources to the service splitting function in the service function orchestration layer; + +2. Splitting function determines whether the service function can be split and splits them into several sub-service functions according to the service type which has been stored in the resource pool, or according to the service task quantity; + +3. Splitting function sends the information of service functions and sub-service functions, and requirements for network, computing and storage resources together to the ordering function in the service function orchestration layer; + +4. Ordering function makes the service functions and sub-service functions have appropriate order, indicating whether serial processing mode and parallel processing mode is applied; especially for serial processing mode, the pre-order relationship is required to be indicated; + +5. Ordering function sends the ordering results to the selection function in the service function orchestration layer; +6. Selection function selects the appropriate resource pools for each service function and each sub-service function based on the order sequences and requirements for network, computing and storage resources; +7. Selection function sends the selection results to the orchestration function in the service function orchestration layer; +8. Orchestration function realizes the service function orchestration based on the results, and for parallel processing mode it is required to be consolidated on the specified node; +9. Orchestration function in the service function orchestration layer sends the policy and configuration instruction to the control layer; +10. As described in clause 11.1, the control layer sends the corresponding configuration result to the infrastructure layer, and the infrastructure layer sends the execution result to the control layer; Therefore, the control layer sends the execution result to the orchestration function in the service function orchestration layer; +11. Orchestration function in the service function orchestration layer sends the execution result to the service layer to realize billing, demonstration, and other purposes. + +## **12 Security considerations** + +The security considerations for a functional architecture of service function orchestration based on SFC are aligned with [ITU-T Y.2324] and [ITU-T Y.2501]. + +## Bibliography + +- [b-IETF RFC 7665] IETF RFC 7665 (2015), *Service Function Chaining (SFC) Architecture*. +<> + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/Y/T-REC-Y.2349-202409-I_PDF-E/raw.md b/marked/Y/T-REC-Y.2349-202409-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..c39688c878a35199108320c873d2e1d103dda28f --- /dev/null +++ b/marked/Y/T-REC-Y.2349-202409-I_PDF-E/raw.md @@ -0,0 +1,454 @@ + + +# Recommendation + +## **ITU-T Y.2349 (09/2024)** + +SERIES Y: Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities + +Next Generation Networks – Enhancements to NGN + +--- + +**Requirements and framework of multi-dimensional resource matching of next generation network evolution based on distributed ledger technology** + +## ITU-T Y-SERIES RECOMMENDATIONS + +### Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities + +| | | +|-------------------------------------------------------------------|----------------------| +| GLOBAL INFORMATION INFRASTRUCTURE | Y.100-Y.999 | +| INTERNET PROTOCOL ASPECTS | Y.1000-Y.1999 | +| NEXT GENERATION NETWORKS | Y.2000-Y.2999 | +| Frameworks and functional architecture models | Y.2000-Y.2099 | +| Quality of Service and performance | Y.2100-Y.2199 | +| Service aspects: Service capabilities and service architecture | Y.2200-Y.2249 | +| Service aspects: Interoperability of services and networks in NGN | Y.2250-Y.2299 | +| Enhancements to NGN | Y.2300-Y.2399 | +| Network management | Y.2400-Y.2499 | +| Computing power networks | Y.2500-Y.2599 | +| Packet-based Networks | Y.2600-Y.2699 | +| Security | Y.2700-Y.2799 | +| Generalized mobility | Y.2800-Y.2899 | +| Carrier grade open environment | Y.2900-Y.2999 | +| FUTURE NETWORKS | Y.3000-Y.3499 | +| CLOUD COMPUTING | Y.3500-Y.3599 | +| BIG DATA | Y.3600-Y.3799 | +| QUANTUM KEY DISTRIBUTION NETWORKS | Y.3800-Y.3999 | +| INTERNET OF THINGS AND SMART CITIES AND COMMUNITIES | Y.4000-Y.4999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T Y.2349 + +# Requirements and framework of multi-dimensional resource matching of next generation network evolution based on distributed ledger technology + +## Summary + +Recommendation ITU-T Y.2349 provides the requirements and framework of multi-dimensional resource matching (MDRM) of next generation network evolution (NGNe) based on distributed ledger technology (DLT) and specifies scenarios and capability requirements which are derived from use cases. + +## History \* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T Y.2349 | 2024-09-13 | 13 | 11.1002/1000/16124 | + +## Keywords + +Distributed ledger technology, matching, multi-dimensional resource, orchestration. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2024 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | | Page | +|---|------------------------------------------------------------------------|------| +| 1 | Scope ..... | 1 | +| 2 | References..... | 1 | +| 3 | Definitions ..... | 1 | +| | 3.1 Terms defined elsewhere..... | 1 | +| | 3.2 Terms defined in this Recommendation..... | 2 | +| 4 | Abbreviations and acronyms ..... | 2 | +| 5 | Conventions ..... | 2 | +| 6 | Background and motivations ..... | 3 | +| | 6.1 Introduction to multi-dimensional resource matching ..... | 3 | +| | 6.2 Introduction to distributed ledger technology (DLT)..... | 3 | +| | 6.3 Introduction to orchestration ..... | 3 | +| | 6.4 MDRM of NGNe based on DLT ..... | 4 | +| 7 | General framework of MDRM of NGNe based on DLT ..... | 4 | +| | 7.1 Overview of MDRM of NGNe based on DLT ..... | 4 | +| | 7.2 General descriptions of MDRM of NGNe based on DLT ..... | 5 | +| 8 | Requirements of MDRM of NGNe based on DLT ..... | 7 | +| | 8.1 Service requirements of MDRM of NGNe based on DLT..... | 7 | +| | 8.2 Capability requirements of MDRM of NGNe based on DLT ..... | 7 | +| 9 | Security considerations..... | 8 | +| | Appendix I – Scenarios and use cases of MDRM of NGNe based on DLT..... | 9 | +| | I.1 The scenario of large-scale AI algorithm training..... | 9 | + + + +# Recommendation ITU-T Y.2349 + +# Requirements and framework of multi-dimensional resource matching of next generation network evolution based on distributed ledger technology + +# 1 Scope + +This Recommendation provides an overview and defines the requirements and framework of multi-dimensional resource matching (MDRM) of next generation network evolution (NGNe) based on distributed ledger technology (DLT). + +The scope of this Recommendation includes: + +- General framework of MDRM of NGNe based on DLT. +- Requirements of MDRM of NGNe based on DLT, including service requirements and capability requirements. +- Use cases and workflow of MDRM of NGNe based on DLT. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- [ITU-T F.751.0] Recommendation ITU-T F.751.0 (2020), *Requirements for distributed ledger systems*. +- [ITU-T X.1400] Recommendation ITU-T X.1400 (2020), *Terms and definitions for distributed ledger technology*. +- [ITU-T Y.2323] Recommendation ITU-T Y.2323 (2018), *Requirements and capabilities of orchestration in next generation network evolution*. +- [ITU-T Y.2342] Recommendation ITU-T Y.2342 (2019), *Scenarios and capability requirements of blockchain in next generation network evolution*. +- [ITU-T Y.2345] Recommendation ITU-T Y.2345 (2023), *Scenarios and requirements of network resource sharing based on distributed ledger technology*. +- [ITU-T Y.3302] Recommendation ITU-T Y.3302 (2017), *Functional architecture of software-defined networking*. + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 consensus** [ITU-T X.1400]: Agreement that a set of transactions is valid. + +**3.1.2 consensus mechanism** [ITU-T X.1400]: Rules and procedures by which consensus is reached. + +**3.1.3 distributed ledger** [ITU-T X.1400]: A type of ledger that is shared, replicated, and synchronized in a distributed and decentralized manner. + +**3.1.4 smart contract** [ITU-T X.1400]: A program written on a distributed ledger system that encodes the rules for specific types of distributed ledger system transactions in a way that can be validated, and triggered by specific conditions. + +## **3.2 Terms defined in this Recommendation** + +None. + +# **4 Abbreviations and acronyms** + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|-------|----------------------------------------------| +| AI | Artificial Intelligence | +| API | Application Programming Interface | +| AR | Augmented Reality | +| BSS | Business Support System | +| DLT | Distributed Ledger Technology | +| E2E | End to End | +| IoT | Internet of Things | +| MDRM | Multi-Dimensional Resource Matching | +| NFV | Network Function Virtualization | +| NFV-O | Network Function Virtualization Orchestrator | +| NGN | Next-Generation Network | +| NGNe | Next-Generation Network Evolution | +| NMS | Network Management System | +| P2P | Peer to Peer | +| SDK | Software Development Kit | +| SDN | Software-Defined Networking | +| SDN-O | Software-Defined Networking Orchestrator | +| VR | Virtual Reality | + +# **5 Conventions** + +In this Recommendation: + +The keywords "is required to" indicate a requirement which must be strictly followed and from which no deviation is permitted, if conformance to this Recommendation is to be claimed. + +The keywords "is recommended" indicate a requirement which is recommended but which is not absolutely required. Thus, this requirement need not be present to claim conformance. + +# 6 Background and motivations + +## 6.1 Introduction to multi-dimensional resource matching + +The advent of 5G networks and the development of new technologies in recent years, including the Internet of things (IoT), artificial intelligence (AI), and big data, have led to a large number terminal access and diversified comprehensive application scenarios, e.g., immersive interaction and smart cities. Virtual reality (VR)/augmented reality (AR) that requires higher performance and user-end applications is becoming abundant, and users' demand for real-time, convenience, and personalization network resources is gradually increasing. These complex applications require multi-dimensional resource matching (MDRM). Multi-dimensional resources include network resources (like computing, storage and bandwidth), data resources, algorithm resources, and application development tools, which are scattered among different resource providers, and need to be organized and coordinated to support MDRM demands. + +MDRM includes multi-dimensional resource demand division, resource demand analysis, resource status monitoring, matching policy generation, and resource allocation and orchestration, to improve the utilization of the idle resources of each resource provider and meet the comprehensive requirements of various resources in complex and diverse application scenarios. In NGNe, more and more application scenarios put forward strong requirements for comprehensive matching and orchestration of multi-dimensional resources. For example, large-scale AI model training scenarios require multi-party resource providers' cooperation of data, algorithm and computing power resources. Activating the potential of scattered and idle resources, and realizing distributed coordination, matching and scheduling will maximize the interests of both users and resource providers. + +## 6.2 Introduction to distributed ledger technology (DLT) + +Distributed ledger technology (DLT) can support safe, credible, and orderly collaboration and coordination among distributed network resource providers by the characteristics of decentralized consensus, smart contract and encryption mechanisms. It also can ensure that the identity of users accessing into the network is trustworthy and verifiable [ITU-T Y.2345]. With the support of DLT-enabled incentive mechanisms and smart contracts technology, matching process execution can be achieved automatically. + +## 6.3 Introduction to orchestration + +Orchestration in NGNe supports NGN and incorporates new technologies, including software-defined networking (SDN) and network function virtualization (NFV), especially from the network evolution perspective. To achieve end-to-end (E2E) orchestration, orchestration in NGNe is required to incorporate NGNs and networks that are implemented by appropriate SDN and NFV technologies [ITU-T Y.2323]. + +Figure 6-1 presents the framework of orchestration in NGNe. + +![Figure 6-1: Framework of orchestration in NGNe. The diagram shows a layered architecture. At the top are 'Portal' and 'BSS' boxes. Below them is a large orange box labeled 'Orchestration in NGNe'. Inside this orange box, there are three dashed-line boxes labeled 'NGN', 'SDN', and 'NFV'. Below the 'Orchestration in NGNe' box is a dashed-line box containing three sub-boxes: 'NMS' (under NGN), 'SDN-O' (under SDN), and 'NFV-O' (under NFV). A reference 'Y.2349(24)' is at the bottom right.](b28af4985cdef1e519e3aaf26561dcb3_img.jpg) + +``` +graph TD + Portal[Portal] --- Orchestration[Orchestration in NGNe] + BSS[BSS] --- Orchestration + subgraph Orchestration [Orchestration in NGNe] + NGN[NGN] + SDN[SDN] + NFV[NFV] + end + subgraph Bottom [ ] + NMS[NMS] + SDN_O[SDN-O] + NFV_O[NFV-O] + end + NGN --- NMS + SDN --- SDN_O + NFV --- NFV_O +``` + +Y.2349(24) + +Figure 6-1: Framework of orchestration in NGNe. The diagram shows a layered architecture. At the top are 'Portal' and 'BSS' boxes. Below them is a large orange box labeled 'Orchestration in NGNe'. Inside this orange box, there are three dashed-line boxes labeled 'NGN', 'SDN', and 'NFV'. Below the 'Orchestration in NGNe' box is a dashed-line box containing three sub-boxes: 'NMS' (under NGN), 'SDN-O' (under SDN), and 'NFV-O' (under NFV). A reference 'Y.2349(24)' is at the bottom right. + +Figure 6-1 – Framework of orchestration in NGNe [ITU-T Y.2323] + +Orchestration can be used to arrange, configure and coordinate a set of operations in multi-domain, multi-layer or E2E heterogeneous networking environments in order to execute a specific task in SDN [ITU-T Y.3302]. + +In MDRM, orchestration could gather the resource from multi-platforms and provide a capability of resource orchestration between resource collection and allocation. + +## 6.4 MDRM of NGNe based on DLT + +As the network function evolves to the organizational function stage (orchestrating and managing multi-dimensional resources in the entire network), facing the matching requirements of multi-dimensional resources in diversified scenarios, MDRM based on DLT can organize the scattered idle resources of users to help improve the utilization of such resources by incentive mechanisms. With the support of orchestration, which can provide a capability of multi-dimensional resource gathering, requirements divided and requirements allocating for multi-dimensional matching, the single-dimension demand can be matched directly by the contract, and the multi-dimensional resource demand can be split and orchestrated to single dimension and matched automatically by the contract. The general flow of MDRM-DLT is shown in Figure 6-2, and the detailed use cases are presented in Appendix I. + +![Figure 6-2: General flow of MDRM-DLT. The diagram shows a flow starting from a 'User' icon, going down to a 'Task scenario' box, then to an 'Orchestration' box. From 'Orchestration', an arrow labeled 'Divided into subtasks' points to a large box labeled 'Resource matching based on DLT'. Inside this box is a dashed box labeled 'Matching policy and consensus', which sits above a box labeled 'DLT nodes' containing three network icons. An arrow from the 'DLT nodes' box points up to the 'Matching policy and consensus' box. A feedback loop arrow goes from the right side of the 'Resource matching based on DLT' box back up to the 'User' icon. The text 'Y.2349(24)' is at the bottom right of the diagram.](daa4a6fa7e2ba1954258f86b4928eb32_img.jpg) + +``` + +graph TD + User((User)) --> TaskScenario[Task scenario] + TaskScenario --> Orchestration[Orchestration] + Orchestration -- "Divided into subtasks" --> ResourceMatching[Resource matching based on DLT] + subgraph ResourceMatchingBox [Resource matching based on DLT] + MatchingPolicy[Matching policy and consensus] + DLTNodes[DLT nodes] + MatchingPolicy -.-> DLTNodes + DLTNodes --> MatchingPolicy + end + ResourceMatchingBox --> User + +``` + +Y.2349(24) + +Figure 6-2: General flow of MDRM-DLT. The diagram shows a flow starting from a 'User' icon, going down to a 'Task scenario' box, then to an 'Orchestration' box. From 'Orchestration', an arrow labeled 'Divided into subtasks' points to a large box labeled 'Resource matching based on DLT'. Inside this box is a dashed box labeled 'Matching policy and consensus', which sits above a box labeled 'DLT nodes' containing three network icons. An arrow from the 'DLT nodes' box points up to the 'Matching policy and consensus' box. A feedback loop arrow goes from the right side of the 'Resource matching based on DLT' box back up to the 'User' icon. The text 'Y.2349(24)' is at the bottom right of the diagram. + +**Figure 6-2 – General flow of MDRM-DLT** + +# 7 General framework of MDRM of NGNe based on DLT + +## 7.1 Overview of MDRM of NGNe based on DLT + +The framework of MDRM based on DLT involves three key elements, namely, DLT service provider, orchestration and resource allocation nodes; The DLT service provider provides the infrastructure to distributed record and consensus, and orchestration acquires the multi-dimensional request from demand side. Based on the provider nodes status in the distributed ledger, orchestration splits multi-dimensional resources into multi single-dimensional resources. After splitting, multi single-dimensional requests need to be sent to the resource allocation nodes, so that the resource allocation nodes can allocate the resources of the corresponding resource provider according to single-dimensional requests and sends them to the user. + +There are three roles, namely, demand side, supply side and DLT service provider, which work together to promote MDRM. These roles are described as follows (see also Figure 7-1): + +- User/demand side: send multi-dimensional resource request to orchestration, and receive the resource from provider/supply side. +- Provider/supply side: extract resources (e.g., computing, storage and data) from repository according to allocation information of resource allocation nodes, and feedback to user/demand side. +- DLT service provider: deploy and maintain the DLT infrastructure, acquire nodes status from DLT and provide it for orchestration. + +![Figure 7-1 – Framework for this Recommendation. This diagram illustrates the MDRM framework involving three main components: User/demand side, DLT service provider, and Provider/supply side. The User/demand side sends 'Multi-dimensional requirements' to the 'Orchestration' layer. The Orchestration layer contains 'Resource requirements access', 'Requirements deconstruction or fractionalized', and 'Requirements matching'. It sends 'Single-dimensional requirements' to the 'Resource allocation nodes' layer. The DLT service provider (DLT platform) handles 'Deploy' and 'Maintain' tasks, providing 'Nodes status' to the Orchestration layer and 'Status and sharing policy' to the Resource allocation nodes. The Resource allocation nodes (containing 'Manage resource catalogues/metadata', 'Consensus algorithm', 'Monitoring resource status', 'Match resource', 'Call smart contract', and 'Resource allocation') send a 'Call the smart contract' signal to the 'Provider/supply side'. The Provider/supply side (containing 'Resource status reporting', 'Resource sharing', 'Open resource sharing API', and a 'Repository') sends an 'Allocate resource' signal back to the User/demand side's 'Receive resource' block. A reference 'Y.2349(24)' is noted at the bottom right.](e9314c83043183351ed74908e9bf2f90_img.jpg) + +Figure 7-1 – Framework for this Recommendation. This diagram illustrates the MDRM framework involving three main components: User/demand side, DLT service provider, and Provider/supply side. The User/demand side sends 'Multi-dimensional requirements' to the 'Orchestration' layer. The Orchestration layer contains 'Resource requirements access', 'Requirements deconstruction or fractionalized', and 'Requirements matching'. It sends 'Single-dimensional requirements' to the 'Resource allocation nodes' layer. The DLT service provider (DLT platform) handles 'Deploy' and 'Maintain' tasks, providing 'Nodes status' to the Orchestration layer and 'Status and sharing policy' to the Resource allocation nodes. The Resource allocation nodes (containing 'Manage resource catalogues/metadata', 'Consensus algorithm', 'Monitoring resource status', 'Match resource', 'Call smart contract', and 'Resource allocation') send a 'Call the smart contract' signal to the 'Provider/supply side'. The Provider/supply side (containing 'Resource status reporting', 'Resource sharing', 'Open resource sharing API', and a 'Repository') sends an 'Allocate resource' signal back to the User/demand side's 'Receive resource' block. A reference 'Y.2349(24)' is noted at the bottom right. + +**Figure 7-1 – Framework for this Recommendation** + +## 7.2 General descriptions of MDRM of NGNe based on DLT + +MDRM of NGNe based on DLT requires that every participating entity be able to connect to each other (e.g., point-to-point) and follows the same DLT protocols and mechanisms, e.g., consensus mechanism, transaction mechanism and ledger structure. DLT, the key technologies of MDRM achieve the functions of storage, authentication, smart contract and transaction as follows: + +- Storage: multi-dimensional requests and single-dimensional resources should be written to the DLT to record and query. +- Authentication: it is required that DLT achieve decentralized authentication. All users and NGNe multi-dimensional resources should be authenticated before participating in the procedure of MDRM. +- Smart contract deployment: NGNe with MDRM is required that the capability of deploy smart contracts to realize resource requirements analysis, resource status monitoring and resource matching, respectively. + +- Transaction: all matching relationships of resources and requests are required to be recorded in the distributed ledger in the form of a transaction. In addition, after MDRM, it is required to record the transaction in the distributed ledger. + +Orchestration, the key element of MDRM, is required to provide the following capabilities: + +- Acquire the MDRM requirements from demand side. +- Read/receive the nodes/resource status (including online, stability and availability) and matching policy (like priority call for urgent needs, and cross-domain call for scarce resources). +- Analyse the demand information of various resources by MDRM request. +- Divide multi-dimensional resource requirement into multiple single-dimensional resource sub-tasks according to the node's status of supply side on the distribute ledger, to be specific, matching the multi-dimensional demand with resource availability. +- Acquire the single-dimensional resource and send it to resource allocation nodes directly. + +Resource allocation nodes are required to provide the capability to receive the request of single-dimensional resources from orchestration and allocate the resource of supply side for the user by smart contract, which can also be the resource provider, as follows: + +- The capability of managing resource catalogues: it is required that resource allocation nodes can collate resource information from providers/supply side to generate resource catalogues. +- The capability of resource matching: receive single-dimensional requirements from orchestration and schedule the algorithms to match resources that meet the demands. +- The capability of consensus algorithm adoption: executive consensus algorithm to record the information. +- The capability of invoking smart contract: configure DLT function to invoke smart contract. +- The capability of monitoring resource status: monitor the status of NGNe resources in real time and update the resource catalogues in a timely manner. +- The capability of resource allocation: based on the matching result, allocate the physical NGNe resources of providers /supply side and provide access (e.g., interface). + +Provider/supply side is the provider of multi-dimensional resources. It is required that provider/supply side have NGNe resources and have the ability to provide these resources to users/demand side, as follows: + +- The capability of reporting resource status: analyse the status of its own NGNe resources and debug it when errors occur. +- The capability of policy control for resource sharing: generate policy on how to provide external resource support when resources are needed. +- The capability of open resource-sharing API: provide and update resource-sharing API to resource allocation nodes. + +User/demand side puts forward multi-dimensional resource requirements and is required to submit them to the orchestration in the form of requests, as follows: + +- The capability of deploying DLT-enabled functions: deploy the simple functions based on DLT, including transaction-publishing function, account management function (key management), etc. +- The capability of providing resource requirements: provide resource requirements to orchestration in the form of multi-dimensional resource requirements based on transaction of DLT. +- The capability of receiving resources: receive resources from provider/supply side through API and invoke the resources to perform tasks. + +# **8 Requirements of MDRM of NGNe based on DLT** + +## **8.1 Service requirements of MDRM of NGNe based on DLT** + +### **8.1.1 Service requirements of MDRM of NGNe based on DLT** + +It is required that the user has a trusted identity to avoid malicious nodes joining and competing for resources. + +It is required to provide a capability to monitor and alert node service performance. + +### **8.1.2 Access requirements of MDRM of NGNe based on DLT** + +It is required to adopt a peer-to-peer (P2P) network as its underlying infrastructure [ITU-T F.751.0] to supporting the function of the DLT platform. + +It is recommended to provide a capability to support more service nodes and support heterogeneous network resources. + +It is required to provide a capability to monitor and alert the performance and status of nodes and resources. + +It is recommended to provide unique network access for specific services. + +It is required to run stably on NGNe networks. + +It is recommended to optionally protect the accessing of multi-dimensional resource records in shared ledger in some use cases. + +## **8.2 Capability requirements of MDRM of NGNe based on DLT** + +### **8.2.1 Requirements of orchestration in MDRM** + +Orchestration in NGNe is required to support global network resource management and optimization in the combined networks [ITU-T Y.2323]. + +It is required to provide resource requirements access to acquire a global view of multi-dimensional requirements from user/demand side among different networks. + +It is required to acquire the node status (e.g., idle or active) from DLT service provider. + +It is required to acquire the resource status and allocation from resource allocation nodes. + +It is required to provide a capability of requirements deconstruction. This capability can divide one multi-dimensional requirement into multiple single-dimensional requirements to resource allocation nodes. + +It is required to provide a capability of requirements matching to allocation and release of network resources. + +It is required to provide a capability of rollback initiation of unsuccessful resource allocation. + +It is required to provide a capability of creation and updating of network connections and, if a malicious node is found, the DLT service provider should, through the consensus mechanism of [ITU-T X.1400], protect network stability, considering that the attacker needs to master more than half of the DLT nodes to achieve the attack. + +### **8.2.2 Requirements of DLT in MDRM** + +In this Recommendation, DLT nodes can be realized as components of DLT-enhanced NGNe infrastructure. + +DLT nodes are required to maintain a shared ledger to ensure the consistency of multi-dimensional resource allocation. + +DLT nodes are required to provide the consensus mechanism for MDRM-DLT. The consensus mechanism guarantees a consistent and authentic matching process by distributed nodes. + +DLT nodes are required to send out broadcast messages, which are sent to all the other nodes in the NGNe network. + +DLT nodes are required to provide the economic model for achieving incentives for participants. + +DLT nodes are required to support smart contracts for MDRM-DLT to execute resource allocation and matching automatically, and also could support incentive execution. + +DLT nodes are required to provide mechanisms to validate matching results, and are also required to be tamper resistant to record the results. + +DLT nodes are required to provide the suitable software development kit (SDK) tools for relevant stakeholders. + +# **9 Security considerations** + +This Recommendation is the specified application in NGNe. Thus it supports the security features for NGN and follows the security considerations identified in [ITU-T Y.2701]. + +The main aspects of security considerations of orchestration in MDRM-DLT shall be aligned with orchestration in NGNe [ITU-T Y.2323], and security considerations of DLT in NGNe shall be aligned with DLT series [ITU-T F.751.0]. + +# Appendix I + +## Scenarios and use cases of MDRM of NGNe based on DLT + +(This appendix does not form an integral part of this Recommendation.) + +## I.1 The scenario of large-scale AI algorithm training + +A typical scenario of satisfying user requirements to perform large-scale AI training utilizing mMDRM of NGNe based on DLT is illustrated in Figure I.1. + +![Figure I.1: MDRM of NGNe based on DLT in the scenario of large-scale AI algorithm training. The diagram illustrates the process from user requirements to resource allocation. On the left, 'Users' send a 'Large-scale AI algorithm training task' (Multi-dimensional resource requirement) to an 'Orchestration' layer. The Orchestration layer contains 'Algorithm resources', 'Data resources', 'Network resources (computing, storage, bandwidth)', and 'Development tools'. These are 'Divided into sub-tasks' and sent to the 'Resource matching based on DLT' layer. This layer includes 'Resource requirements analysis', 'Resource status monitoring', 'Matching strategy', and 'Broadcast and decentralized consensus'. Below this, a network of 'Allocation nodes' (storage and computing resource provider, algorithm resource provider, bandwidth resource provider, application development tools resource provider, data resource provider, and data resource, computing idle resource provider) is shown. An arrow labeled 'Allocate resource' points from the network back to the Orchestration layer. A feedback loop labeled 'Multi-dimensional resource providing' goes from the network back to the 'Users'.](9b6b5924b48bf2fd5f347f88f06f45b3_img.jpg) + +Y.2349(24) + +Figure I.1: MDRM of NGNe based on DLT in the scenario of large-scale AI algorithm training. The diagram illustrates the process from user requirements to resource allocation. On the left, 'Users' send a 'Large-scale AI algorithm training task' (Multi-dimensional resource requirement) to an 'Orchestration' layer. The Orchestration layer contains 'Algorithm resources', 'Data resources', 'Network resources (computing, storage, bandwidth)', and 'Development tools'. These are 'Divided into sub-tasks' and sent to the 'Resource matching based on DLT' layer. This layer includes 'Resource requirements analysis', 'Resource status monitoring', 'Matching strategy', and 'Broadcast and decentralized consensus'. Below this, a network of 'Allocation nodes' (storage and computing resource provider, algorithm resource provider, bandwidth resource provider, application development tools resource provider, data resource provider, and data resource, computing idle resource provider) is shown. An arrow labeled 'Allocate resource' points from the network back to the Orchestration layer. A feedback loop labeled 'Multi-dimensional resource providing' goes from the network back to the 'Users'. + +**Figure I.1 – MDRM of NGNe based on DLT in the scenario of large-scale AI algorithm training** + +As long as the resource provider enters the network environment according to the standard and registers resources on the DLT, all the scattered resources in various network systems can participate in matching and scheduling. Each of these providers has deployed a resource allocation node, which is also the core node of the DLT platform, and can participate in decentralized consensus. These providers can provide various types of resources, such as network resources, data resources, algorithm resources, and development tools and models. + +When a user or terminal device accesses into a network system, it can provide resource requirements. For example, as shown in Figure I.1, the user sends a requirement for a series resource to perform large-scale AI algorithm training tasks. These tasks can be received, analysed, and divided into sub-tasks in the orchestration layer according to the resource type. Next, these sub-tasks will be sent to the resource allocation node to perform the matching process. The detailed process of resource matching based on DLT includes the following: + +- In order to achieve a complete matching process, the resource allocation nodes will first analyse the detailed requirements of each sub-task. + +- Next, considering jointly the requirements of sub-tasks and the resource status of the user, a resource allocation conclusion will be given. The resource status of the user can be achieved on the metrics monitored and gained from users. +- Then, on the basis of this resource allocation conclusion, the node will query various corresponding resources on the DLT platform and execute resource allocation decisions based on smart contracts. The node will broadcast the message of successful resource matching, and achieve decentralized consensus among all the DLT nodes, and then instruct the distributed resource providers to provide corresponding resources to the user. + +During the device running period, the resource allocation node will also monitor the device running status in real time, to dynamically adjust resource-matching policies. + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/Y/T-REC-Y.2621-201108-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg b/marked/Y/T-REC-Y.2621-201108-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..83de44cfa91ff96cd6d044185230bbdca1aff85e --- /dev/null +++ b/marked/Y/T-REC-Y.2621-201108-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:92c3c68bcdb95caa413d3d9a4747655489556a99ef57b3def4ad289d99ef7337 +size 6615 diff --git a/marked/Y/T-REC-Y.2621-201108-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg b/marked/Y/T-REC-Y.2621-201108-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..0ea3acfcc1a3933fc2d73b49a4558438879b835d --- /dev/null +++ b/marked/Y/T-REC-Y.2621-201108-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:8a026f92c4174464d717a8cadff2e68405f88e52dad4de15b0db44d4b03ea537 +size 27984 diff --git a/marked/Y/T-REC-Y.2621-201108-I_PDF-E/raw.md b/marked/Y/T-REC-Y.2621-201108-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..e7748cea2a5fc6e44312c39f92cc34a4eba1520c --- /dev/null +++ b/marked/Y/T-REC-Y.2621-201108-I_PDF-E/raw.md @@ -0,0 +1,359 @@ + + +I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +## Y.2621 + +(08/2011) + +SERIES Y: GLOBAL INFORMATION +INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS +AND NEXT-GENERATION NETWORKS + +Next Generation Networks – Smart ubiquitous networks + +# --- **Requirements for an independent, scalable control plane in future, packet-based networks** + +Recommendation ITU-T Y.2621 + +![ITU logo: A blue globe with red lightning bolts and the text 'ITU International Telecommunication Union'.](84a1d09fb489061482111515543b60dc_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with two red lightning bolts striking it. To the right of the globe, the text 'ITU' is written in a large, bold, blue font, and below it, the words 'International Telecommunication Union' are written in a smaller, blue font. + +ITU logo: A blue globe with red lightning bolts and the text 'ITU International Telecommunication Union'. + +# ITU-T Y-SERIES RECOMMENDATIONS **GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT- GENERATION NETWORKS** + +| | | +|--------------------------------------------------------------------|----------------------| +| GLOBAL INFORMATION INFRASTRUCTURE | | +| General | Y.100–Y.199 | +| Services, applications and middleware | Y.200–Y.299 | +| Network aspects | Y.300–Y.399 | +| Interfaces and protocols | Y.400–Y.499 | +| Numbering, addressing and naming | Y.500–Y.599 | +| Operation, administration and maintenance | Y.600–Y.699 | +| Security | Y.700–Y.799 | +| Performances | Y.800–Y.899 | +| INTERNET PROTOCOL ASPECTS | | +| General | Y.1000–Y.1099 | +| Services and applications | Y.1100–Y.1199 | +| Architecture, access, network capabilities and resource management | Y.1200–Y.1299 | +| Transport | Y.1300–Y.1399 | +| Interworking | Y.1400–Y.1499 | +| Quality of service and network performance | Y.1500–Y.1599 | +| Signalling | Y.1600–Y.1699 | +| Operation, administration and maintenance | Y.1700–Y.1799 | +| Charging | Y.1800–Y.1899 | +| IPTV over NGN | Y.1900–Y.1999 | +| NEXT GENERATION NETWORKS | | +| Frameworks and functional architecture models | Y.2000–Y.2099 | +| Quality of Service and performance | Y.2100–Y.2199 | +| Service aspects: Service capabilities and service architecture | Y.2200–Y.2249 | +| Service aspects: Interoperability of services and networks in NGN | Y.2250–Y.2299 | +| Numbering, naming and addressing | Y.2300–Y.2399 | +| Network management | Y.2400–Y.2499 | +| Network control architectures and protocols | Y.2500–Y.2599 | +| Smart ubiquitous networks | Y.2600–Y.2699 | +| Security | Y.2700–Y.2799 | +| Generalized mobility | Y.2800–Y.2899 | +| Carrier grade open environment | Y.2900–Y.2999 | +| Future networks | Y.3000–Y.3099 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# **Recommendation ITU-T Y.2621** + +# **Requirements for an independent, scalable control plane in future, packet-based networks** + +## **Summary** + +Recommendation ITU-T Y.2621 describes the technical requirements for an independent, scalable control plane (iSCP) by separating the control plane from the data plane in future packet-based networks (FPBNs). The requirements include reachability, scalability, flexibility, reliability, manageability, service, security, interworking, routing and forwarding. + +## **History** + +| Edition | Recommendation | Approval | Study Group | +|---------|----------------|------------|-------------| +| 1.0 | ITU-T Y.2621 | 2011-08-06 | 13 | + +## **Keywords** + +Forwarding, FPBN, iSCP, network entity, routing, scalability, separation, virtual network element. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2012 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|-----------------------------------------------|-------------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 1 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 2 | +| 6 Overview of iSCP ..... | 2 | +| 7 iSCP requirements ..... | 4 | +| 7.1 Reachability ..... | 4 | +| 7.2 Scalability ..... | 4 | +| 7.3 Flexibility ..... | 4 | +| 7.4 Reliability ..... | 4 | +| 7.5 Manageability ..... | 4 | +| 7.6 Services..... | 5 | +| 7.7 Security ..... | 5 | +| 7.8 Interworking ..... | 5 | +| 7.9 Routing ..... | 5 | +| 7.10 Forwarding ..... | 5 | +| 8 Security considerations ..... | 5 | +| Bibliography..... | 6 | + +## **Introduction** + +The rapid, continued increase of the number of users, their bandwidth and service requirements, the scalability and controllability of the control plane, the data plane and the management plane of network nodes and of the whole network, are major challenges for future evolution. One of the reasons for issues related to the scalability and controllability of today's IP networks is that the functional architecture of the control plane is not optimal. In current IP networks, the control plane and the data plane are integrated into network nodes, and more and more control and service functionalities are added in the network nodes. IP networks have become complex, thus making it difficult to maintain or extend them. + +The independent, scalable control plane (iSCP), which separates the control plane from the data plane in future packet-based networks (FPBNs), can alleviate such problems of scalability and controllability in current IP networks. The iSCP has specific requirements derived from its architectural characteristics. + +# Recommendation ITU-T Y.2621 + +# Requirements for an independent, scalable control plane in future, packet-based networks + +## 1 Scope + +This Recommendation describes the technical requirements for an independent, scalable control plane (iSCP) by separating the control plane from the data plane in future packet-based networks (FPBNs) as described in [ITU-T Y.2601]. Recognizing scenarios described in [b-ITU-T Y-Sup. 11], the requirements of iSCP provided in this Recommendation cover reachability, scalability, flexibility, reliability, manageability, services, security, interworking, routing and forwarding. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- [ITU-T Y.2011] Recommendation ITU-T Y.2011 (2004), *General principles and general reference model for Next Generation Networks*. +- [ITU-T Y.2601] Recommendation ITU-T Y.2601 (2006), *Fundamental characteristics and requirements of future packet based networks*. + +# 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +- 3.1.1 control plane** [ITU-T Y.2011]: The set of functions that controls the operation of entities in the stratum or layer under consideration, plus the functions required to support this control. +- 3.1.2 data plane** [ITU-T Y.2011]: The set of functions used to transfer data in the stratum or layer under consideration. +- 3.1.3 management plane** [ITU-T Y.2011]: The set of functions used to manage entities in the stratum or layer under consideration, plus the functions required to support this management. + +### 3.2 Terms defined in this Recommendation + +This Recommendation defines the following terms: + +- 3.2.1 future packet-based network (FPBN):** A network architecture providing the topmost layer(s) of the transport stratum as defined in [ITU-T Y.2011]. + +NOTE 1 – This definition is based on the description of FPBN in [ITU-T Y.2601]. + +NOTE 2 – Fundamental characteristics and requirements of future packet-based networks are defined in [ITU-T Y.2601]. + +- 3.2.2 independent scalable control plane (iSCP):** An architectural approach of future packet-based networks (FPBNs) which consists in separating the control plane from the data plane. + +NOTE – Fundamental characteristics and requirements of future packet-based networks are defined in [ITU-T Y.2601]. + +## **4 Abbreviations and acronyms** + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|------|-------------------------------------| +| CE | Control Element | +| FE | Forwarding Element | +| FIB | Forwarding Information Base | +| FPBN | Future Packet-Based Network | +| iSCP | independent, Scalable Control Plane | +| LSP | Label Switched Path | +| ME | Management Element | +| MIB | Management Information Base | +| MPLS | Multi-Protocol Label Switching | +| NAT | Network Address Translation | +| P2P | Peer-to-Peer | +| QoS | Quality of Service | +| RIB | Routing Information Base | +| SCE | Service Control Element | +| SPE | Service Processing Element | +| TTL | Time To Live | +| VNE | Virtual Network Element | +| VPN | Virtual Private Network | + +## **5 Conventions** + +In this Recommendation: + +The keywords "is required to" indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this document is to be claimed. + +The keywords "is recommended" indicate a requirement which is recommended but which is not absolutely required. Thus this requirement needs not to be present to claim conformance. + +The keyword "entity" indicates a CE, SCE, FE, SPE, ME or VNE. + +# **6 Overview of iSCP** + +As shown in Figure 6-1, iSCP adopts a particular architecture that separates the control plane from the data plane in the future packet-based network (FPBN). + +![Figure 6-1: Overview of iSCP architecture. The diagram shows three main planes: Management plane (yellow), Control plane (blue), and Data plane (purple). The Management plane contains a Management Element (ME). The Control plane contains Control Elements (CE) and Service Control Elements (SCE). The Data plane contains Forwarding Elements (FE) and Service-Processing Elements (SPE). A dashed red box labeled 'VNE' (Virtual-Network Element) encloses the CE, SCE, FE, and SPE components, indicating they form a single logical entity. The reference Y.2621(11)_F6-1 is noted at the bottom right.](ebff22fb5dd6f50a90e44dca0f82f285_img.jpg) + +Figure 6-1: Overview of iSCP architecture. The diagram shows three main planes: Management plane (yellow), Control plane (blue), and Data plane (purple). The Management plane contains a Management Element (ME). The Control plane contains Control Elements (CE) and Service Control Elements (SCE). The Data plane contains Forwarding Elements (FE) and Service-Processing Elements (SPE). A dashed red box labeled 'VNE' (Virtual-Network Element) encloses the CE, SCE, FE, and SPE components, indicating they form a single logical entity. The reference Y.2621(11)\_F6-1 is noted at the bottom right. + +**Figure 6-1 – Overview of iSCP** + +The control plane of iSCP contains mechanisms dealing with operating the packets and deciding the pathways for user traffic. These mechanisms will be implemented in control elements (CEs) and service control elements (SCEs). The data plane of iSCP contains mechanisms for forwarding and processing user traffic. These mechanisms will be implemented in forwarding elements (FEs) and service-processing elements (SPEs). The management plane of iSCP contains mechanisms dealing with the operation, administration and management aspects of an iSCP-based network, which is a network based on iSCP as an architectural approach. These mechanisms will be implemented in management elements (MEs). + +In the context of iSCP, a single conventional network entity, e.g., a router, can be constructed using multiple network entities such as CEs, SCEs, FEs and SPEs. The resulting constructed entity is called a virtual-network element (VNE). Depending on the required capacity and flexibility, the number of individual entities used for the VNE can vary. In a typical scenario, a small number (e.g., one or two in a case of redundancy) of CEs control a large number of FEs. + +In a VNE, one CE can control one or a group of FE(s) through the control plane. The CE will generate the rules for FE(s) to forward certain traffic, and download the rules to FE(s). To generate these rules, the CE maintains necessary information in a routing information base (RIB) to compute the most suitable route for incoming packets. The RIB is updated by communicating with other CEs through routing protocols. Then CE(s) generate a forwarding-information base (FIB) based on the RIB, and download the FIB to FE(s). + +One SCE can control associated SPE(s) through the control plane. The SCE maintains a policy database and generates the rules for SPE(s) to process certain traffic. These rules are based on service policies, configured by ME(s), and are maintained as a service-control table. For example, service policies include QoS behaviour policies and access-control policies. The SCE enforces the rules by setting service control table(s) in the associated SPE(s). + +An FE forwards incoming packets according to the FIB that was generated and given through the control plane by the CE(s). The FE receives and updates the FIB from the CE, looks up the FIB to obtain the next-hop information of packets, and forwards the packets. + +An SPE handles incoming packets according to the service control table. The SPE receives and updates the service control table given through the control plane by the SCE(s), looks up the table, and handles packets according to the table. The SPE can process packets with some mechanisms such as network-address translation (NAT), encryption/decryption, protocol conversion, content processing, etc. + +An ME manages the resources of CE(s), SCE(s), FE(s) and SPE(s) in terms of configuration, fault, accounting, performance, and security management, through the management plane. + +# **7 iSCP requirements** + +This clause describes the requirements derived from the characteristics of iSCP as described in clause 6. These requirements cover: reachability, scalability, flexibility, reliability, manageability, services, security, interworking, routing and forwarding. + +## **7.1 Reachability** + +- (1) The iSCP is required to support communication mechanisms between CEs and FEs and between SCEs and SPEs. +- (2) The iSCP is required to support the route checking mechanisms to confirm the reachability between CEs and FEs and between SCEs and SPEs. + +## **7.2 Scalability** + +- (1) The iSCP is required to support scalability of the capacities, performance and functions of CEs, FEs, SCEs and SPEs, independently. +- (2) The CE is required to control multiple FEs. The number of FEs controlled by one CE is required to be changed easily in the iSCP-based network. +- (3) The SCE is required to control multiple SPEs. The number of SPEs controlled by one SCE is required to be changed easily in the iSCP-based network. +- (4) The iSCP is required to support scalable sizes of the RIB in the CE, of the policy database in the SCE, of the FIB in the FE, and of the service-control table in the SPE. + +## **7.3 Flexibility** + +- (1) The iSCP is required to provide easy and flexible addition, deletion, and upgrading of the functions supported by CEs, FEs, SCEs and SPEs. +- (2) The iSCP is required to provide easy and flexible addition, deletion, and upgrade of CEs, FEs, SCEs and SPEs in the iSCP-based network. +- (3) The iSCP is required to cope with frequent topology changes, such as adding, deleting and changing the status of CEs, FEs, SCEs and SPEs. + +## **7.4 Reliability** + +- (1) The iSCP is required to support mechanisms for fault tolerance of CEs and SCEs. Backup CEs and SCEs are recommended to be provided. +- (2) The iSCP is required to enable CEs, FEs, SCEs and SPEs to detect faults of their connected entities, to restore the connections with the recovered or alternate entities, and to (re)synchronize the status. +- (3) The iSCP is required to allow multiple CEs and SCEs to work together to support load-balancing for different application scenarios. + +## **7.5 Manageability** + +- (1) The iSCP is required to allow ME(s) to manage all entities resources. This includes the means of accessing all entities in a distributed environment and the capabilities of monitoring and configuring all entities resources. +- (2) The iSCP is required to allow ME(s) to deliver the configuration information for constructing a given VNE to the entities that will constitute that VNE, so that these entities be able to construct this VNE based on the required configuration. + +(3) The iSCP is required to allow ME(s) to manage management information bases (MIBs) of all entities, including CEs, FEs, SCEs, SPEs and VNEs. + +## **7.6 Services** + +(1) The iSCP-based network is required to support the transport functions required for the support of NGN services and Internet services. + +(2) The iSCP-based network is required to support tunnelling functions, such as for the support of MPLS LSP tunnels, etc. + +(3) The iSCP-based network is required to support VPN functions, such as related to MPLS VPN, etc. + +## **7.7 Security** + +(1) The iSCP is required to protect the communication between entities from attacks, such as man-in-the-middle, snooping and impersonation. + +(2) The iSCP is required to support service-traffic isolation among multiple services (see clause 7.6 (1)). + +## **7.8 Interworking** + +(1) The iSCP-based network is required to communicate with legacy networks, such as IP- or MPLS-based networks, by edge equipments that are used to exchange routing information and service policy (e.g., peer-to-peer (P2P) service acceleration policy) between the iSCP-based network and legacy networks. + +(2) VNEs are required to process the time to live (TTL) value of incoming packets, as done by legacy packet network routers. + +## **7.9 Routing** + +(1) For routing within a VNE, CEs are required to calculate the RIB within a VNE, taking into account the routing policy. + +(2) For routing among VNEs, CEs are required to exchange the routing information among VNEs and calculate the RIB reflecting the route among VNEs. + +(3) For routing between a VNE and an external network, CEs are required to exchange the routing information with any external network routing node connected with the VNE and to calculate the RIB reflecting the route between the VNE and the external network. + +## **7.10 Forwarding** + +FEs are required to receive FIBs from the connected CEs and to forward the packets according to the FIBs. + +# **8 Security considerations** + +Security considerations specific to iSCP are given in clause 7.7. + +## Bibliography + +The following documents contain information that may be valuable to the reader of this Recommendation. They provide additional information about topics covered within this Recommendation, but are not essential for an understanding of this Recommendation. + +- [b-ITU-T Y-Sup.11] ITU-T Y.2600-series Recommendations – Supplement 11 (2010), *Supplement on scenarios for independent scalable control plane (iSCP) in future packet-based networks (FPBN)*. +- [b-IETF RFC 3654] IETF RFC 3654 (2003), *Requirements for Separation of IP Control and Forwarding*. +- [b-IETF RFC 3746] IETF RFC 3746 (2004), *Forwarding and Control Element Separation (ForCES) Framework*. +- [b-IETF RFC 5810] IETF RFC 5810 (2010), *Forwarding and Control Element Separation (ForCES) Protocol Specification*. +- [b-IETF RFC 5811] IETF RFC 5811 (2010), *SCTP-Based Transport Mapping Layer (TML) for the Forwarding and Control Element Separation (ForCES) Protocol*. +- [b-IETF RFC 5812] IETF RFC 5812 (2010), *Forwarding and Control Element Separation (ForCES) Forwarding Element Model*. +- [b-IETF RFC 5813] IETF RFC 5813 (2010), *Forwarding and Control Element Separation (ForCES) MIB*. +- [b-IETF RFC 6041] IETF RFC 6041 (2010), *Forwarding and Control Element Separation (ForCES) Applicability Statement*. +- [b-IETF RFC 6053] IETF RFC 6053 (2010), *Implementation Report for Forwarding and Control Element Separation (ForCES)*. +- [b-IETF RFC 4364] IETF RFC 4364 (2006), *BGP/MPLS IP Virtual Private Networks (VPNs)*. + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|--------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Terminals and subjective and objective assessment methods | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/Y/T-REC-Y.2741-201101-I_PDF-E/2b3a967f6ce4f23649be995a353e39f8_img.jpg b/marked/Y/T-REC-Y.2741-201101-I_PDF-E/2b3a967f6ce4f23649be995a353e39f8_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..539b686dcd516bc0566707864d47c6fd3ecf1cec --- /dev/null +++ b/marked/Y/T-REC-Y.2741-201101-I_PDF-E/2b3a967f6ce4f23649be995a353e39f8_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:e6efc6e7e8c0d5ca3e907d289a91f878d79b2de4a33d6bde7850b1d596db685e +size 29520 diff --git a/marked/Y/T-REC-Y.2741-201101-I_PDF-E/2cde062fd82833415971a8bd1a2cafab_img.jpg b/marked/Y/T-REC-Y.2741-201101-I_PDF-E/2cde062fd82833415971a8bd1a2cafab_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..180d417bc189f3d258a7fdb1d0db9d81fb5958aa --- /dev/null +++ b/marked/Y/T-REC-Y.2741-201101-I_PDF-E/2cde062fd82833415971a8bd1a2cafab_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:c26104efd510964c8fb15e68c9a214be4ddfea36e0149a543abe50cccf898f03 +size 27668 diff --git a/marked/Y/T-REC-Y.2741-201101-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg b/marked/Y/T-REC-Y.2741-201101-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..b6db67dc033c5aaa6d198adea90daa302bde202d --- /dev/null +++ b/marked/Y/T-REC-Y.2741-201101-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:59252b2f8644d842bed54f9900a893cc2d7bc24006e17c9915b42dac750aa9f7 +size 37331 diff --git a/marked/Y/T-REC-Y.2741-201101-I_PDF-E/5a9282ac54ca7bc50f1d2ab6cfb376ba_img.jpg b/marked/Y/T-REC-Y.2741-201101-I_PDF-E/5a9282ac54ca7bc50f1d2ab6cfb376ba_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..0e530fb5cd813cde3f0ca6eb157f6fe77ed06200 --- /dev/null +++ b/marked/Y/T-REC-Y.2741-201101-I_PDF-E/5a9282ac54ca7bc50f1d2ab6cfb376ba_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:664891540be04e5e7b86e9d857f110e0adb0611920d1a2f14b20336f68ba36c8 +size 26557 diff --git a/marked/Y/T-REC-Y.2741-201101-I_PDF-E/5cab96b2d23174c25919840ecd50aa48_img.jpg b/marked/Y/T-REC-Y.2741-201101-I_PDF-E/5cab96b2d23174c25919840ecd50aa48_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..6ef1c2f579db40c31ed7fad56e80afbd7c120646 --- /dev/null +++ b/marked/Y/T-REC-Y.2741-201101-I_PDF-E/5cab96b2d23174c25919840ecd50aa48_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:063a8e560e534e1394c0855e0bb2495848edfe80aa1f7fb33626898a1aa898d5 +size 22833 diff --git a/marked/Y/T-REC-Y.2741-201101-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg b/marked/Y/T-REC-Y.2741-201101-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..8c80dff9f67d33dc53f7e64954b979fcb49abf53 --- /dev/null +++ b/marked/Y/T-REC-Y.2741-201101-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:80e2829601a7e409ccbbe8b8e2505af7f8cdea60ee72e5c5d87d33a7f2c61151 +size 6691 diff --git a/marked/Y/T-REC-Y.2741-201101-I_PDF-E/9b9d2abd741ed4bafe7f78f89961c663_img.jpg b/marked/Y/T-REC-Y.2741-201101-I_PDF-E/9b9d2abd741ed4bafe7f78f89961c663_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..cc196ced6930a77a660b44c810cbebb6deb1ef3e --- /dev/null +++ b/marked/Y/T-REC-Y.2741-201101-I_PDF-E/9b9d2abd741ed4bafe7f78f89961c663_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:51e203ddc9a14b67051fdfef21647d4aa55db8c43e38b0036bdf9b75f23acd0b +size 25720 diff --git a/marked/Y/T-REC-Y.2741-201101-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg b/marked/Y/T-REC-Y.2741-201101-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..1a42c3b588515e468e5173649c686f4a06c9ba03 --- /dev/null +++ b/marked/Y/T-REC-Y.2741-201101-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:9fb1632571be69d142f48d863bc3bf979457de5123a7883e5e30d5a6bf967bd3 +size 33198 diff --git a/marked/Y/T-REC-Y.2741-201101-I_PDF-E/c5452f95f3b28f1bfe29e84fbc2e1267_img.jpg b/marked/Y/T-REC-Y.2741-201101-I_PDF-E/c5452f95f3b28f1bfe29e84fbc2e1267_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..5b2b3773727674943e068ac5ed299b275d94b74e --- /dev/null +++ b/marked/Y/T-REC-Y.2741-201101-I_PDF-E/c5452f95f3b28f1bfe29e84fbc2e1267_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:d8780de20026a58fa8298a92aee9a7b76c8e68e783bc84c95593d9c703108605 +size 36396 diff --git a/marked/Y/T-REC-Y.2741-201101-I_PDF-E/c5655e700cc3e9aac7e9f4f07f30264d_img.jpg b/marked/Y/T-REC-Y.2741-201101-I_PDF-E/c5655e700cc3e9aac7e9f4f07f30264d_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..76ae903695fa94cb7c9b314d65e73a5a1eb576d9 --- /dev/null +++ b/marked/Y/T-REC-Y.2741-201101-I_PDF-E/c5655e700cc3e9aac7e9f4f07f30264d_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:e5f604991200d2a7986179aa9eb078a5daf4c0968ff003dfcf718e8d0e5d912e +size 37937 diff --git a/marked/Y/T-REC-Y.2741-201101-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg b/marked/Y/T-REC-Y.2741-201101-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..4f160b45d0fb94cdd41cd5ee00b0225dd7b0b7cf --- /dev/null +++ b/marked/Y/T-REC-Y.2741-201101-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:d8afa31b26f48f79ad1276db37a5bfa380fde5b940dbb55db149fd36b9168407 +size 21270 diff --git a/marked/Y/T-REC-Y.2741-201101-I_PDF-E/raw.md b/marked/Y/T-REC-Y.2741-201101-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..765a20b295ea5e9793eea43bd467197154ded6af --- /dev/null +++ b/marked/Y/T-REC-Y.2741-201101-I_PDF-E/raw.md @@ -0,0 +1,1152 @@ + + +I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +# Y.2741 + +(01/2011) + +SERIES Y: GLOBAL INFORMATION +INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS +AND NEXT-GENERATION NETWORKS + +Next Generation Networks – Security + +# --- **Architecture of secure mobile financial transactions in next generation networks** + +Recommendation ITU-T Y.2741 + +![ITU logo: a globe with red lightning bolts and the text 'ITU International Telecommunication Union'](84a1d09fb489061482111515543b60dc_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with two red lightning bolts striking it. To the right of the globe, the text "ITU" is written in a large, bold, blue font, and below it, the words "International Telecommunication Union" are written in a smaller, blue font. + +ITU logo: a globe with red lightning bolts and the text 'ITU International Telecommunication Union' + +# ITU-T Y-SERIES RECOMMENDATIONS **GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT- GENERATION NETWORKS** + +| | | +|--------------------------------------------------------------------|----------------------| +| GLOBAL INFORMATION INFRASTRUCTURE | | +| General | Y.100–Y.199 | +| Services, applications and middleware | Y.200–Y.299 | +| Network aspects | Y.300–Y.399 | +| Interfaces and protocols | Y.400–Y.499 | +| Numbering, addressing and naming | Y.500–Y.599 | +| Operation, administration and maintenance | Y.600–Y.699 | +| Security | Y.700–Y.799 | +| Performances | Y.800–Y.899 | +| INTERNET PROTOCOL ASPECTS | | +| General | Y.1000–Y.1099 | +| Services and applications | Y.1100–Y.1199 | +| Architecture, access, network capabilities and resource management | Y.1200–Y.1299 | +| Transport | Y.1300–Y.1399 | +| Interworking | Y.1400–Y.1499 | +| Quality of service and network performance | Y.1500–Y.1599 | +| Signalling | Y.1600–Y.1699 | +| Operation, administration and maintenance | Y.1700–Y.1799 | +| Charging | Y.1800–Y.1899 | +| IPTV over NGN | Y.1900–Y.1999 | +| NEXT GENERATION NETWORKS | | +| Frameworks and functional architecture models | Y.2000–Y.2099 | +| Quality of Service and performance | Y.2100–Y.2199 | +| Service aspects: Service capabilities and service architecture | Y.2200–Y.2249 | +| Service aspects: Interoperability of services and networks in NGN | Y.2250–Y.2299 | +| Numbering, naming and addressing | Y.2300–Y.2399 | +| Network management | Y.2400–Y.2499 | +| Network control architectures and protocols | Y.2500–Y.2599 | +| Smart ubiquitous networks | Y.2600–Y.2699 | +| Security | Y.2700–Y.2799 | +| Generalized mobility | Y.2800–Y.2899 | +| Carrier grade open environment | Y.2900–Y.2999 | +| Future networks | Y.3000–Y.3099 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +## **Recommendation ITU-T Y.2741** + +# **Architecture of secure mobile financial transactions in next generation networks** + +## **Summary** + +Recommendation ITU-T Y.2741 specifies the general architecture of a security solution for mobile commerce and mobile banking in the context of NGN. It describes the key participants, their roles, and the operational scenarios of the mobile commerce and mobile banking systems. It also provides examples of the implementation models of mobile commerce and mobile banking systems. + +## **History** + +| Edition | Recommendation | Approval | Study Group | +|---------|----------------|------------|-------------| +| 1.0 | ITU-T Y.2741 | 2011-01-28 | 13 | + +## **Keywords** + +Mobile banking, mobile commerce, mobile payments, remote payments, safety and security. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2011 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | | Page | +|---|------------------------------------------------------------------------------------------|-------------| +| 1 | Scope ..... | 1 | +| 2 | References..... | 1 | +| 3 | Definitions ..... | 1 | +| | 3.1 Terms defined elsewhere..... | 1 | +| | 3.2 Terms defined in this Recommendation..... | 1 | +| 4 | Abbreviations and acronyms ..... | 2 | +| 5 | Conventions ..... | 2 | +| 6 | Roles, risks, participants, and scenarios of mobile payments in NGN..... | 2 | +| | 6.1 Roles within the mobile commerce and mobile banking systems..... | 2 | +| | 6.2 Risks in the MPS and MPS security levels ..... | 3 | +| | 6.3 Participants and the system architecture of mobile commerce and mobile banking ..... | 3 | +| | 6.4 The mobile payment system usage scenarios ..... | 5 | +| 7 | Transition from the token payment systems..... | 16 | +| | Appendix I – Enrol a payment instrument in the system..... | 17 | +| | Appendix II – Mobile banking and mobile commerce systems implementation models ..... | 19 | +| | II.1 The implementation of the system without the use of the client application ..... | 20 | +| | II.2 The implementation of the system with the use of the client application ..... | 20 | +| | Bibliography..... | 22 | + + + +## Recommendation ITU-T Y.2741 + +# Architecture of secure mobile financial transactions in next generation networks + +# 1 Scope + +This Recommendation defines the security architecture pertaining to remote mobile financial transactions for NGN. The scope excludes all other financial transactions, as well as transactions that use monetary or non-monetary tokens for transfer of value. + +By organizing a wide range of services with a flexible management and personalization functions, NGN can provide convenient access to mobile payment system (MPS) services. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[ITU-T Y.2740] Recommendation ITU-T Y.2740 (2011), *Security requirements for mobile remote financial transactions in next generation networks*. + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following term defined elsewhere: + +**3.1.1 next generation network (NGN)** [b-ITU-T Y.2001]: A packet-based network able to provide telecommunication services to users and able to make use of multiple broadband, QoS-enabled transport technologies and in which service-related functions are independent from underlying transport-related technologies. It enables unfettered access for users to networks and to competing service providers and/or services of their choice. It supports generalized mobility which will allow consistent and ubiquitous provision of services to users. + +## 3.2 Terms defined in this Recommendation + +This Recommendation defines the following terms: + +**3.2.1 application:** A special mobile banking or mobile commerce application uploaded to the client's (user's) mobile device. + +**3.2.2 bank account:** An electronic funds account held by a private individual or a corporate entity in a bank or other financial institution authorized by the country's national monetary authority (e.g., central bank) that can be used for payment for goods and services. + +**3.2.3 client:** A private individual or a corporate entity that has signed a contractual agreement on the use of telecommunication services and the system of mobile commerce. + +**3.2.4 financial transaction:** An event or a condition covered under the terms of the contract between a buyer and a seller to exchange an asset for payment. + +**3.2.5 intersystem environment:** A set of rules or a system that enables the establishment of the interaction of various mobile bank and mobile commerce systems. + +**3.2.6 mobile device:** An electronic device used for telecommunications over wireless NGN network. + +**3.2.7 mobile financial transaction:** A financial transaction initiated and/or authorized using a mobile device. + +**3.2.8 mobile payment system (MPS):** Mobile banking and/or mobile commerce systems. + +**3.2.9 monetary token:** Electronic or physical artifact used for payment that is represented and measured in the country's national currency units, that however is not stored in, or directly linked to a bank account. + +An example of an electronic monetary token is electronic cash stored in a stand-alone electronic wallet that is not mirrored by a bank account. Examples of physical monetary tokens include coins, banknotes, traveller's checks, etc. + +**3.2.10 non-monetary token:** Electronic or physical artifact used for payment but not represented in national currency units. Examples of electronic non-monetary tokens are unused 'minutes' or 'SMS messages' held in NGN subscriber accounts that the NGN operators allow to be transferred from one subscriber account to another. + +**3.2.11 payment ID:** A required request parameter that explicitly identifies the payment recipient. Merchant ID and mobile payment system (MPS) ID (a unique identifier of a mobile payment system) must be present in the implementation of the intersystem environment. + +# **4 Abbreviations and acronyms** + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|-----|-------------------------| +| DB | DataBase | +| ID | Identification | +| IS | Information System | +| MPS | Mobile Payment System | +| NGN | Next Generation Network | + +# **5 Conventions** + +None. + +# **6 Roles, risks, participants, and scenarios of mobile payments in NGN** + +## **6.1 Roles within the mobile commerce and mobile banking systems** + +The basic roles of the MPS participants and their responsibilities are: + +- The client is a mobile subscriber who possesses a payment instrument for the payment operations. +- The client application is the special software uploaded to the client's mobile device (phone, SIM card, communicator, etc.) and designed for conducting secure mobile payment operations. +- The payment instrument is a financial instrument used to perform payment for goods and services. + +- The NGN operator provides the mobile communication network for remote interaction of the client with the MPS, data routing and transfer. +- The client application distributor is a participant that makes applications available to the clients. +- The security provider is a participant that provides security of the data transfer over communications channels. +- The MPS operator (service provider, payment gateway) is a participant that ensures interaction within the MPS and provides payment services to the end user. +- The issuer is a financial institution that issues payment instruments. +- The client authentication provider validates the client operation. +- The acquirer is a financial institution that maintains merchant relationships and receives all financial transactions from the merchant. +- The payment system is an organization that ensures interbank payment transactions. + +## **6.2 Risks in the MPS and MPS security levels** + +This clause describes the basic information security risks that may arise when conducting (i.e., performing) remote mobile payments. These risks include, but are not limited to: + +- The risk of compromised confidentiality – unauthorized third party access to confidential information. +- The risk of compromised integrity – information distortion during the process of its transfer or processing. +- The risk of forging of electronic documents – a document is generated by an unauthorized party. +- The risk of repudiation – the denial of authorship of an electronic document. +- The risk of information destruction, either intentional or by negligence. +- Transactional risk – the failure to finish a transaction (e.g., due to unstable mobile communication). +- Depending on the implemented risk-based security mechanisms, there are systems with four security levels [ITU-T Y.2740]. + +## **6.3 Participants and the system architecture of mobile commerce and mobile banking** + +The MPS architecture should be compliant with the already existing system of interrelations between financial, legal and commercial organizations and enable system participants to make mobile payment transactions with the necessary degree of security based on the estimated risk level. The proposed architecture should support schemes and specifications already used by the system participants for performing payment transactions. + +![Figure 1: Participants and the system architecture of the mobile commerce and the mobile banking. The diagram shows a central 'MPS operator' box connected to 'Client', 'NGN operator', 'Merchant', 'Issuer', and 'Acquirer'. The 'MPS operator' box contains the text: '- Security provider;', '- Client authentication provider;', '- Service provider'.](a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg) + +``` + +graph TD + Client[Client] --- NGN[NGN operator] + Client --- Issuer[Issuer] + NGN --- MPS[MPS operator] + Merchant[Merchant] --- MPS + MPS --- Issuer + MPS --- Acquirer[Acquirer] + subgraph MPS_operator [MPS operator] + direction TB + S1["- Security provider;"] + S2["- Client authentication provider;"] + S3["- Service provider"] + end + +``` + +Figure 1: Participants and the system architecture of the mobile commerce and the mobile banking. The diagram shows a central 'MPS operator' box connected to 'Client', 'NGN operator', 'Merchant', 'Issuer', and 'Acquirer'. The 'MPS operator' box contains the text: '- Security provider;', '- Client authentication provider;', '- Service provider'. + +ITU-T Y.2741(11)\_F01 + +**Figure 1 – Participants and the system architecture of the mobile commerce and the mobile banking** + +**Table 1 – Mobile payments system participants** + +| Participant | Description, concern (goal, objective, interest) | Role | +|--------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------| +| Client | Private individual or corporate entity that has signed a contractual agreement on the use of telecommunication services and the system of mobile commerce.
Possesses a mobile device and a payment instrument.
Principal concern: increase the number of services, get the possibility to perform secure remote financial transactions, expand the scope of payment instruments. | Client | +| NGN operator | An institution that provides the client with digital communication services.
Principal concern: increase the number of clients, extend the range of the available services, increase traffic. | NGN operator | +| MPS operator | An institution that ensures secure remote interaction of the financial structures, the client and the NGN operator within the mobile payment system.
Principal concern: create an extensive network of mobile commerce, increase the number of participants as well as the number of remote transactions, ensure maximum operations security. | Security provider, service provider, client authentication provider | +| Issuer | Financial and legal institution that issues and services payment instruments.
Principal concern: increase the use of the issued payment instruments, increase the number of clients. | Issuer | +| Acquirer | Financial and legal institution that accepts payments for the products or services on behalf of a merchant.
Principal concern: increase the number of transactions of the merchants it services. | Acquirer | + +**Table 1 – Mobile payments system participants** + +| Participant | Description, concern (goal, objective, interest) | Role | +|--------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------| +| Merchant | Corporate entity that provides goods or services and receives payment from the client.
Principal concern: promote its goods and services, increase the number of clients, increase the possible ways of payment for the goods and services. | Merchant | + +The participants may combine the roles depending on the architecture implementation. + +Obtaining the required security level described in [ITU-T Y.2740] may require the introduction of the roles of a client application, a client applications distributor, or both. The former is uploaded to clients mobile devices; the latter can be performed by the NGN operator, the mobile payment operator, or by a third party. + +When cards of international payment systems are used as payment instruments, the role of the payment system is integral. + +## **6.4 The mobile payment system usage scenarios** + +### **6.4.1 Basic usage scenarios** + +#### **6.4.1.1 Enrol client in MPS** + +*Aim:* To subscribe the client to the service within the MPS. + +*The basic roles: their goals and objectives* + +Client: to get the opportunity to use the MPS services. + +MPS operator: to enrol a new client in the MPS. + +##### *Maximum guarantees* + +The client's consent to the terms and conditions of the MPS use is registered; + +The client is registered in the IS of the MPS operator; + +The client receives the activation code. + +##### *Minimum guarantees* + +Enrolment is denied to the client with the indication of the cause of denial; + +The MPS operator logs the client's cancellation of the enrolment. + +##### *Initial data of the scenario* + +There is no active client profile in the MPS: the client has not been enrolled in the MPS or his/her profile has been removed earlier. + +##### *Basic steps of the scenario* + +1. The client initiates the enrolment: + - a) at the office of the MPS operator; + - b) by means of the web-interface: the client is authorized at the MPS operator's website and the request for enrolment is sent. +2. The client is authenticated within the MPS. +3. The MPS operator IS creates client's data, profile in the DB. + +![Figure 2: Enrol client in MPS. Two sequence diagrams showing client enrollment. Diagram (a) shows a Client sending a message '1' to an MPS operator (Note), which then sends messages '2,3' to the Client. Diagram (b) shows a Client sending a message '1' to an NGN operator, which then sends a message '1' to an MPS operator (Note), which finally sends messages '2,3' to the Client.](d4af765160d04ecef538e5066006dc77_img.jpg) + +``` + +sequenceDiagram + participant Client + participant MPS_operator as MPS operator (Note) + Client->>MPS_operator: 1 + MPS_operator-->>Client: 2,3 + + participant Client + participant NGN_operator as NGN operator + participant MPS_operator as MPS operator (Note) + Client->>NGN_operator: 1 + NGN_operator->>MPS_operator: 1 + MPS_operator-->>Client: 2,3 + +``` + +a) at the MPS operator office + +b) by means of a web-interface + +Figure 2: Enrol client in MPS. Two sequence diagrams showing client enrollment. Diagram (a) shows a Client sending a message '1' to an MPS operator (Note), which then sends messages '2,3' to the Client. Diagram (b) shows a Client sending a message '1' to an NGN operator, which then sends a message '1' to an MPS operator (Note), which finally sends messages '2,3' to the Client. + +NOTE – Security provider, client authentication provider, service provider. + +ITU-T Y.2741(11)\_F02 + +**Figure 2 – Enrol client in MPS** + +##### ***Alternative steps of the scenario*** + +###### **3. a. The client has been enrolled in the MPS (has an active profile):** + +The MPS operator IS informs the client that the service has been enrolled before. + +###### **3. b. The client has an account within the MPS but it has been blocked:** + +The MPS operator IS activates the client's account. + +###### **3. c. The MPS operator IS denies registration:** + +- a) The MPS operator IS logs an attempt to connect the service to the client; +- b) The MPS operator IS informs the client on the denial to connect the service and specifies the reasons. + +#### **6.4.1.2 Enrol payment instrument to be used in the MPS** + +The client shall register his or her payment instrument. The following conditions shall be met in the process: + +- the client shall confirm the authority of using the payment instrument being registered; +- in the process of the registration of the payment instrument, a minimum necessary number of parameters for conducting a remote payment transaction by the client shall be stored into the MPS operator DB; +- the parameters of the payment instrument shall be securely stored on the MPS operator's side in a way that excludes unauthorized access and provides the impossibility of conducting the financial transactions that have not been authorized by the client. + +The means of connecting a payment instrument are described in Appendix I. + +#### **6.4.1.3 Perform financial operations by the client in home zone within its own payment system** + +***Aim:*** To provide the possibility to the client to use the financial services of the MPS. + +##### ***The basic roles: their goals and objectives*** + +Client: to use the services offered by the merchant remotely. + +Mobile operator: to transmit the message over communication channels. + +MPS operator: to enable the client to pay for the goods and services by means of the MPS. + +Merchant: to provide remote services to the client. + +Issuer: to provide authorization for and initiate settlement of the client's payment operation. + +Acquirer: to transfer authorization response for the operation of the merchant. + +##### ***The maximum guarantees*** + +The client pays for the service of the merchant. + +The merchant provides the service. + +##### ***The minimum guarantees*** + +The client is denied to pay for the goods and services of the MPS operator. + +##### ***Initial data of the scenario*** + +The client is registered in the MPS and has a payment instrument enrolled into the MPS. + +##### ***Basic steps of the scenario*** + +1. By means of his/her mobile device, the client generates a request that contains the parameters of the financial operation and payment instrument; +2. The request is transmitted via the NGN operator channels; +3. The MPS operator receives the request; +4. The client is authenticated; +5. The required financial operation (remittance/payment) is performed using the client's payment instrument details; +6. The operation result is sent to the client; +7. The response is transmitted via the NGN operator channels; +8. The client receives the result of the financial operation. + +![Sequence diagram showing the process of performing financial operations by the client. The diagram involves five participants: Client, NGN operator, MPS operator (Note), Acquirer, and Merchant. The sequence of messages is: 1. Client sends message 1 to NGN operator. 2. NGN operator sends message 2 to MPS operator. 3. MPS operator sends message 3 to Acquirer. 4. MPS operator sends message 4 to Merchant. 5. Acquirer sends message 5 to Merchant. 6. Merchant sends message 5 to Acquirer. 7. Acquirer sends message 5 to MPS operator. 8. MPS operator sends message 6 to Client. 9. MPS operator sends message 7 to NGN operator. 10. NGN operator sends message 7 to Client. 11. Client sends message 8 to NGN operator.](5a9282ac54ca7bc50f1d2ab6cfb376ba_img.jpg) + +``` +sequenceDiagram + participant Client + participant NGN_operator as NGN operator + participant MPS_operator as MPS operator (Note) + participant Acquirer + participant Merchant + + Client->>NGN_operator: 1 + NGN_operator->>MPS_operator: 2 + MPS_operator->>Acquirer: 3 + MPS_operator->>Merchant: 4 + Acquirer->>Merchant: 5 + Merchant->>Acquirer: 5 + Acquirer->>MPS_operator: 5 + MPS_operator->>Client: 6 + MPS_operator->>NGN_operator: 7 + NGN_operator->>Client: 7 + Client->>NGN_operator: 8 +``` + +Sequence diagram showing the process of performing financial operations by the client. The diagram involves five participants: Client, NGN operator, MPS operator (Note), Acquirer, and Merchant. The sequence of messages is: 1. Client sends message 1 to NGN operator. 2. NGN operator sends message 2 to MPS operator. 3. MPS operator sends message 3 to Acquirer. 4. MPS operator sends message 4 to Merchant. 5. Acquirer sends message 5 to Merchant. 6. Merchant sends message 5 to Acquirer. 7. Acquirer sends message 5 to MPS operator. 8. MPS operator sends message 6 to Client. 9. MPS operator sends message 7 to NGN operator. 10. NGN operator sends message 7 to Client. 11. Client sends message 8 to NGN operator. + +NOTE – Security provider, client authentication provider, service provider. + +ITU-T Y.2741(11)\_F03 + +**Figure 3 – Performing financial operations by the client** + +###### ***Alternative steps of the scenario*** + +**6.     *The client is not authenticated*** + +**7.     *The financial operation is not possible*** + +- a) Transaction rollback is executed; +- b) The operation processing result is returned to the client. + +###### ***Alternative scenario: the merchant initiates a payment*** + +##### ***The basic steps of the scenario are as follows*** + +- 1.     a) the merchant generates a payment offer and sends it to the MPS operator; +- b) the MPS operator determines the client and the way to deliver the payment offer to the client; +- c) the request is sent to the client over the NGN operator channels. +- 2.     The client receives the request through his/her mobile device and generates the response that contains the financial operation parameters as well as the parameters of the payment instrument; +- 3.     The request is transmitted via the NGN operator channels; +- 4.     The MPS operator receives the client's response; +- 5.     Authentication of the client; +- 6.     The required financial operation (remittance/payment) is performed using the client's payment instrument details; +- 7.     The operation result is sent to the client; +- 8.     The response is transmitted via the NGN operator channels; +- 9.     The client receives the result of the financial operation. + +![Sequence diagram showing the process of performing payments initiated by merchant. The diagram involves five participants: Client, NGN operator, MPS operator (Note), Acquirer, and Merchant. The sequence of messages is as follows: 1. Merchant sends '1 a' to NGN operator. 2. NGN operator sends '1 a' to MPS operator. 3. MPS operator sends '1 b' to NGN operator. 4. NGN operator sends '1 c' to Client. 5. Client sends '2' to NGN operator. 6. NGN operator sends '3' to MPS operator. 7. MPS operator sends '4, 5' to Acquirer. 8. Acquirer sends '6' to Merchant. 9. Merchant sends '6' to Acquirer. 10. Acquirer sends '6' to MPS operator. 11. MPS operator sends '7' to NGN operator. 12. NGN operator sends '8' to Client. 13. Client sends '9' to NGN operator.](33ed1f9b27c7c21c797aa928b0f06851_img.jpg) + +``` + +sequenceDiagram + participant Client + participant NGN_operator as NGN operator + participant MPS_operator as MPS operator (Note) + participant Acquirer + participant Merchant + + Merchant->>NGN_operator: 1 a + NGN_operator->>MPS_operator: 1 a + MPS_operator->>NGN_operator: 1 b + NGN_operator->>Client: 1 c + Client->>NGN_operator: 2 + NGN_operator->>MPS_operator: 3 + MPS_operator->>Acquirer: 4, 5 + Acquirer->>Merchant: 6 + Merchant->>Acquirer: 6 + Acquirer->>MPS_operator: 6 + MPS_operator->>NGN_operator: 7 + NGN_operator->>Client: 8 + Client->>NGN_operator: 9 + +``` + +Sequence diagram showing the process of performing payments initiated by merchant. The diagram involves five participants: Client, NGN operator, MPS operator (Note), Acquirer, and Merchant. The sequence of messages is as follows: 1. Merchant sends '1 a' to NGN operator. 2. NGN operator sends '1 a' to MPS operator. 3. MPS operator sends '1 b' to NGN operator. 4. NGN operator sends '1 c' to Client. 5. Client sends '2' to NGN operator. 6. NGN operator sends '3' to MPS operator. 7. MPS operator sends '4, 5' to Acquirer. 8. Acquirer sends '6' to Merchant. 9. Merchant sends '6' to Acquirer. 10. Acquirer sends '6' to MPS operator. 11. MPS operator sends '7' to NGN operator. 12. NGN operator sends '8' to Client. 13. Client sends '9' to NGN operator. + +NOTE – Security provider, client authentication provider, service provider. + +ITU-T Y.2741(11)\_F04 + +**Figure 4 – Performing payments initiated by merchant** + +#### 6.4.1.4 Disconnecting the payment instrument from the MPS + +**Aim:** To enable the client to remove the data about payment instrument from the MPS. + +##### *The basic roles: their goals and objectives* + +Client: to disconnect the payment instrument from the MPS. + +Mobile operator: to transmit the message via communications channels. + +MPS operator: to enable the client to disconnect the payment instrument. + +##### *The maximum guarantees* + +The client disconnects the payment instrument from the MPS. + +##### *The minimum guarantees* + +The client cannot disconnect the payment instrument. + +##### *Initial data of the scenario* + +The client is enrolled in the MPS and has the connected payment instrument. + +##### *Basic steps of the scenario* + +1. By means of his/her mobile device, the client generates the request to disconnect a certain payment instrument; +2. The request is transmitted via the NGN operator channels; +3. The MPS operator receives the request; + +4. The MPS authenticates the client; +5. The payment instrument is removed from the IS DB; +6. The result of the payment instrument disconnection is sent to the client; +7. The response is transmitted via the NGN operator channels; +8. The client receives the operation result. + +![Sequence diagram showing the process of disconnecting a payment instrument from the MPS. The diagram involves three lifelines: Client, NGN operator, and MPS operator (Note). Step 1: Client sends a message to NGN operator. Step 2: NGN operator sends a message to MPS operator. Step 3, 4, 5, 6: MPS operator performs internal actions. Step 7: MPS operator sends a message back to NGN operator. Step 8: NGN operator sends a message back to the Client.](5cab96b2d23174c25919840ecd50aa48_img.jpg) + +``` + +sequenceDiagram + participant Client + participant NGN_operator as NGN operator + participant MPS_operator as MPS operator (Note) + + Client->>NGN_operator: 1 + NGN_operator->>MPS_operator: 2 + Note over MPS_operator: 3, 4, 5, 6 + MPS_operator-->>NGN_operator: 7 + NGN_operator-->>Client: 8 + +``` + +NOTE – Security provider, client authentication provider, service provider. + +ITU-T Y.2741(11)\_F05 + +Sequence diagram showing the process of disconnecting a payment instrument from the MPS. The diagram involves three lifelines: Client, NGN operator, and MPS operator (Note). Step 1: Client sends a message to NGN operator. Step 2: NGN operator sends a message to MPS operator. Step 3, 4, 5, 6: MPS operator performs internal actions. Step 7: MPS operator sends a message back to NGN operator. Step 8: NGN operator sends a message back to the Client. + +**Figure 5 – Disconnecting the payment instrument from the MPS** + +##### ***Alternative steps of the scenario*** + +###### **7. *Disconnecting the payment instrument from the MPS is denied*** + +- a) The MPS operator IS informs the client of the impossibility to disconnect the payment instrument. + +#### **6.4.1.5 Disconnecting the client from the MPS** + +***Aim:*** To disconnect the client from MPS services. + +***The basic roles: their goals and objectives*** + +Client: to abandon the use of the MPS services. + +MPS operator: to make the services inaccessible to the client. + +***The maximum guarantees*** + +The client's cancellation of MPS services is registered. + +The MPS services become inaccessible to the client. + +***The minimum guarantees*** + +The disconnection from the services is denied to the client; the reason is specified. + +The client cancels the disconnection from the MPS services. + +***Initial data of the scenario*** + +The client is enrolled in the MPS. + +##### ***Basic steps of the scenario*** + +1. The client initiates the disconnection from the services: + - at the office of the MPS operator; + - through the web-interface: the client is authorized through the MPS operator's website and orders the disconnection from the service. +2. The client is authenticated in the MPS. +3. The MPS operator IS feeds the client status changes into the DB (the profile is blocked). +4. The client cannot use the MPS services without a re-enrolment. + +![Sequence diagrams showing disconnection scenarios: a) at the MPS operator office and b) by means of a web-interface.](2cde062fd82833415971a8bd1a2cafab_img.jpg) + +The diagram consists of two sequence diagrams, labeled 'a)' and 'b)', illustrating the process of disconnecting a client from MPS services. + +**Diagram a) at the MPS operator office:** This diagram shows two lifelines: 'Client' and 'MPS operator (Note)'. A message arrow labeled '1' points from the Client lifeline to the MPS operator lifeline. On the MPS operator lifeline, there are two additional message arrows, labeled '2' and '3', which are self-messages (indicated by arrows pointing to the same lifeline). + +**Diagram b) by means of a web-interface:** This diagram shows three lifelines: 'Client', 'NGN operator', and 'MPS operator (Note)'. A message arrow labeled '1' points from the Client lifeline to the NGN operator lifeline. Another message arrow labeled '1' points from the NGN operator lifeline to the MPS operator lifeline. On the MPS operator lifeline, there are two additional message arrows, labeled '2' and '3', which are self-messages. + +NOTE – Security provider, client authentication provider, service provider. + +Sequence diagrams showing disconnection scenarios: a) at the MPS operator office and b) by means of a web-interface. + +ITU-T Y.2741(11)\_F06 + +**Figure 6 – Disconnecting the client from the MPS** + +##### ***Alternative steps of the scenario*** + +###### ***1. A payment application is used in the MPS*** + +The client initiates the disconnection from the MPS in the application. + +###### ***3. The client cannot be disconnected from the MPS services*** + +The MPS operator IS informs the client that the service cannot be disconnected at the moment. + +### **6.4.2 Usage scenario with payment application** + +#### **6.4.2.1 Receiving the payment application** + +**Aim:** To provide the client with the possibility to use the application in the MPS. + +##### ***The basic roles: their goals and objectives*** + +Client: to receive the payment application to be used in the mobile device. + +Client applications distributor: to provide the client with the application. + +##### ***The maximum guarantees*** + +The client receives the application. + +##### ***The minimum guarantees*** + +The application is denied to the client. + +The client has no possibility to use the received application because of some technical characteristics of the mobile device. + +##### ***Initial data of the scenario*** + +The client is enrolled in the MPS and possesses a technical possibility to use the application. + +##### ***Basic steps of the scenario:*** + +1. The client receives the application from the client applications distributor: + - at the client applications distributor office; + - through the web-interface (at the client applications distributor website). +2. The client is enabled to use the application on the mobile device. + +![Sequence diagrams showing the process of receiving a payment application. Diagram (a) shows a Client and an MPS operator (Note). The Client sends a message (1) to the MPS operator, and the MPS operator returns a message (2) to the Client. Diagram (b) shows a Client, an NGN operator, and an MPS operator (Note). The Client sends a message (1) to the NGN operator, the NGN operator sends a message (1) to the MPS operator, the MPS operator returns a message (1) to the NGN operator, and the NGN operator returns a message (2) to the Client. Below the diagrams is the text 'NOTE – Client applications distributor.' and the reference 'ITU-T Y.2741(11)_F07'.](9b9d2abd741ed4bafe7f78f89961c663_img.jpg) + +a) at the MPS operator office + +b) by means of a web-interface + +NOTE – Client applications distributor. + +ITU-T Y.2741(11)\_F07 + +Sequence diagrams showing the process of receiving a payment application. Diagram (a) shows a Client and an MPS operator (Note). The Client sends a message (1) to the MPS operator, and the MPS operator returns a message (2) to the Client. Diagram (b) shows a Client, an NGN operator, and an MPS operator (Note). The Client sends a message (1) to the NGN operator, the NGN operator sends a message (1) to the MPS operator, the MPS operator returns a message (1) to the NGN operator, and the NGN operator returns a message (2) to the Client. Below the diagrams is the text 'NOTE – Client applications distributor.' and the reference 'ITU-T Y.2741(11)\_F07'. + +**Figure 7 – Receiving the payment application** + +##### ***Alternative steps of the scenario*** + +###### ***1. a. The client receives the updated version of the application*** + +The client has received the application before. + +###### ***1. b. The client does not receive the application*** + +The client requests help from the support service of the client applications distributor. + +#### **6.4.2.2 Activating the payment application** + +**Aim:** To activate the client's payment application. + +##### ***The basic role: their goals and objectives*** + +Client: to get the possibility to use the MPS services by means of the application. + +MPS operator: to validate the use of the given payment application in the MPS by the given client. + +Mobile operator: to transmit the message via communications channels. + +##### ***The maximum guarantees*** + +The client activates the application. + +The client keys are loaded into the application. + +The client keys are fed into the MPS operator IS DB. + +##### ***The minimum guarantees*** + +The activation of the application is denied to the client; the cause of denial is specified. + +##### ***Initial data of the scenario*** + +The client is enrolled in the MPS, has the activation code and the application in the mobile device. + +##### ***Basic steps of the scenario*** + +1. The client selects "activation" in the application menu; +2. The client presents the activation code received during the enrolment procedure, to the application; +3. The application generates and sends a request to the MPS; +4. The request is transmitted via the NGN operator channels; +5. The MPS operator receives the enquiry. The activation code is verified; +6. The client keys are generated and stored in the MPS provider IS DB; +7. The keys and the activation result are sent to the client; +8. The response is transmitted via the NGN operator channels; +9. The client application receives the message, stores the client keys, and the activation result is displayed to the client; +10. The client receives the access to the MPS services in the application. + +![Sequence diagram showing the activation process between Client (Note 1), NGN operator, and MPS operator (Note 2).](2b3a967f6ce4f23649be995a353e39f8_img.jpg) + +``` +sequenceDiagram + participant Client as Client (Note 1) + participant NGN as NGN operator + participant MPS as MPS operator (Note 2) + + Client->>NGN: 1, 2, 3 + NGN->>MPS: 4 + MPS->>NGN: 5, 6, 7 + NGN->>Client: 8 + Client->>Client: 9, 10 +``` + +NOTE 1 – Client, payment instrument, payment application. + +NOTE 2 – Security provider, client authentication provider, service provider. + +ITU-T Y.2741(11)\_F08 + +Sequence diagram showing the activation process between Client (Note 1), NGN operator, and MPS operator (Note 2). + +**Figure 8 – Activating the payment application** + +##### ***Alternative steps of the scenario*** + +###### **5. Error in the activation code validation:** + +- a) The MPS operator IS informs the client that the activation code is entered incorrectly; +- b) The client's account is blocked if the limit of attempts to enter the activation code is exceeded. + +### **6.4.3 Intersystem interaction usage scenarios** + +This Recommendation deals with general issues and offers basic scenarios of the interaction. + +#### **6.4.3.1 Performing financial transactions when the client is in the roaming** + +**Aim:** To make it possible for the client to use the enabled MPS service when outside the operator coverage area (home zone). + +##### ***The basic roles: their goals and objectives*** + +Client: to get the possibility to pay for the services using the MPS when abroad the home zone. + +Mobile operator: to transmit the message over communications channels. + +MPS operator: to enable the client to pay for the goods and services by means of the MPS. + +Merchant: to render remote services to the client. + +Issuer: to provide authorization for and initiate settlement of the client's payment operation. + +Acquirer: to transfer authorization response for the operation of the merchant. + +##### ***The maximum guarantees*** + +The client pays for the service of the merchant. + +The merchant renders the service. + +##### ***The minimum guarantees*** + +The client is denied to pay for the goods and services of the MPS operator. + +##### ***Initial data of the scenario*** + +The client is registered for MPS; the client is in the roaming area (outside the home zone) and has a connected payment instrument. + +##### ***Basic steps of the scenario*** + +The basic scenario steps are similar to the ones described in the scenario of the financial transaction within the home zone. The client request and the transaction result from the roaming zone and back to the home zone are performed under the roaming rules and are not covered in this Recommendation. + +#### **6.4.3.2 Performing financial operations by the client in another MPS** + +***Aim:*** To enable the client to use the services of a different MPS which the client is not enrolled to. + +##### ***The basic roles: their goals and objectives*** + +Client: to obtain the possibility to pay for the services provided by the merchant located in the coverage zone of a different MPS. + +Mobile operator: to transmit the message over communications channels. + +MPS operator: to enable the client to pay for the goods and services by means of another MPS. + +Merchant: to render remote services to the client. + +Issuer: to provide authorization for and initiate settlement of the client's payment operation. + +Acquirer: to transfer authorization response for the operation of the merchant. + +##### ***The maximum guarantees*** + +The client pays for the service of the merchant. + +The merchant renders the service. + +##### ***The minimum guarantees*** + +The client is denied to pay for the goods and services of the MPS operator. + +##### ***Initial data of the scenario*** + +The client is registered for MPS, has a connected payment instrument and is aware of the merchant details necessary for the payment transaction. + +##### ***Basic steps of the scenario*** + +1. The client generates a request by means of his/her mobile phone. The request contains the financial transaction parameters including payment ID and the parameters of the payment instrument; +2. The request is transmitted over the operator communications channels; +3. The MPS operator receives the request; +4. The client is authenticated; +5. The MPS operator is identified by payment ID; +6. The request is transmitted to the addressee (the operator of a different MPS) over the intersystem secure channels; +7. The required financial transaction using the client payment instrument details is performed; +8. The transaction result is sent to the client's home MPS; +9. MPS generated the response to the client; +10. The response is transmitted over the operator communications channels; +11. The client receives the transaction result. + +![Sequence diagram showing the flow of a financial transaction between a Client, NGN operator, MPS operator, Intersystem environment, Another MPS operator, Acquirer, and Merchant. Steps are numbered 1 through 11.](c5655e700cc3e9aac7e9f4f07f30264d_img.jpg) + +``` + +sequenceDiagram + participant Client + participant NGN as NGN operator + participant MPS as MPS operator (Note 1) + participant IE as Intersystem environment + participant AMPS as Another MPS operator (Note 2) + participant Acquirer + participant Merchant + + Client->>NGN: 1 + NGN->>Client: 2 + NGN->>MPS: 2 + Note over MPS: 3, 4, 5 + MPS->>IE: 6 + IE->>AMPS: 6 + AMPS->>Acquirer: 7 + Acquirer->>Merchant: 7 + Merchant-->>Acquirer: 7 + Acquirer-->>AMPS: 7 + AMPS-->>IE: 8 + IE-->>MPS: 8 + MPS-->>NGN: 9 + NGN-->>Client: 10 + Client-->>Client: 11 + +``` + +Sequence diagram showing the flow of a financial transaction between a Client, NGN operator, MPS operator, Intersystem environment, Another MPS operator, Acquirer, and Merchant. Steps are numbered 1 through 11. + +NOTE 1 – Security provider, client authentication provider, service provider. + +NOTE 2 – Security provider, service provider. + +ITU-T Y.2741(11)\_F09 + +**Figure 9 – Performing financial operations by the client in another MPS** + +##### ***Alternative steps of the scenario*** + +4. ***The client is not authenticated.*** +5. ***MPS cannot be identified.*** +7. ***The financial operation is not possible:*** + - a) Transaction rollback is executed; + - b) The operation performance result is returned to the client. + +# **7 Transition from the token payment systems** + +Some operators have introduced services that enable the transfer of monetary and non-monetary tokens as payment for goods and services, within (and sometimes between) the NGN operators' billing systems. + +Although these services are often represented as conducive for the development of immature economies with large proportions of non-banked population, in the long term these services can be disruptive to the fiscal and monetary systems of these economies. + +Developing countries face a wide range of issues associated with cash-related crime. Development of electronic banking systems in such countries reduces the amount of cash in circulation, and thus leads to the reduction of cash-related crime. + +The NGN operators offering token payment services should therefore develop roadmaps for the migration of these token payment systems to systems using financial transactions for the exchange of value. + +## Appendix I + +### Enrol a payment instrument in the system + +(This appendix does not form an integral part of this Recommendation.) + +**Aim:** To provide the client with the possibility to use his/her payment instrument in the MPS. + +#### ***The basic roles: their goals and objectives*** + +Client: to have an opportunity to take advantage of the MPS using a payment instrument. + +Mobile operator: to transmit the message via communications channels. + +MPS operator: to approve the use of the given payment application in the MPS by the given client. + +Client authentication provider: to authenticate the client and his/her payment instrument. + +#### ***The maximum guarantees*** + +The client receives an opportunity to take advantage of the MPS to use the payment instrument. + +#### ***The minimum guarantees*** + +The given payment instrument is denied to be used by the client. + +#### ***Initial data of the scenario*** + +The client is enrolled in the MPS and has a payment instrument. + +#### ***Basic steps of the scenario*** + +1. By means of his/her mobile device, the client transmits the payment instrument parameters to the MPS operator; +2. The request is transmitted via the NGN operator channels; +3. The MPS operator receives the request; +4. The MPS operator IS generates a random amount; +5. The MPS operator sends a request to reserve this amount at the given payment instrument to the acquirer system. Acquirer sends a request for authorization to the issuer of the payment instrument. The client shall contact the issuer and find out the amount to confirm that he/she is the legitimate owner of payment instrument; +6. The issuer of the payment instrument authenticates the client using its standard means of authentication; +7. After authentication, the issuer informs the client about the value of the reserved amount; +8. The client transmits the value to the MPS operator via the client application; +9. The request is transmitted via the NGN operator channels; +10. Upon receiving the value of the reserved amount from the client, the MPS operator compares it with the previously generated one; +11. Provided that both amounts coincide, the MPS operator stores the information on the payment instrument for further usage in the secure storage, and sends notification with the operation result to the client; +12. Simultaneously, the request is sent to the issuer (via the acquirer) to cancel the amount reservation at the payment instrument. + +![Sequence diagram for Enrol payment instrument in MPS showing interactions between Client, NGN operator, MPS operator (Note), Acquirer, and Issuer.](c5452f95f3b28f1bfe29e84fbc2e1267_img.jpg) + +``` + +sequenceDiagram + participant Client + participant NGN as NGN operator + participant MPS as MPS operator (Note) + participant Acquirer + participant Issuer + + activate Client + Client->>NGN: 1 + activate NGN + NGN->>Client: 2 + deactivate NGN + NGN->>MPS: 3 + activate MPS + MPS->>Acquirer: 4 + activate Acquirer + Acquirer->>Issuer: 5 + activate Issuer + Issuer->>Acquirer: 5 + deactivate Issuer + deactivate Acquirer + MPS->>Issuer: 6 + activate Issuer + deactivate MPS + Issuer->>Client: 7 + deactivate Issuer + Client->>NGN: 8 + activate NGN + NGN->>MPS: 9 + activate MPS + deactivate NGN + MPS->>Client: 10 + deactivate MPS + Client->>NGN: 11 + activate NGN + NGN->>Acquirer: 12 + activate Acquirer + deactivate NGN + Acquirer->>Issuer: 12 + activate Issuer + deactivate Acquirer + deactivate Issuer + deactivate Client + +``` + +NOTE – Security provider, client authentication provider, service provider. + +ITU-T Y.2741(11)\_FI.1 + +Sequence diagram for Enrol payment instrument in MPS showing interactions between Client, NGN operator, MPS operator (Note), Acquirer, and Issuer. + +**Figure I.1 – Enrol payment instrument in MPS** + +#### *Alternative steps of the scenario* + +- 10.** *The value of the previously reserved amount does not coincide with the one entered by the client* + +The client receives an error notification. When the number of failed attempts exceeds three, the mobile device client's profile is blocked in the MPS system. The reserved amount is cancelled. + +# Appendix II + +## Mobile banking and mobile commerce systems implementation models + +(This appendix does not form an integral part of this Recommendation.) + +This appendix describes the examples of basic mobile banking and mobile commerce systems implementation models subject to the implemented security level. + +The following terms are used in this appendix: + +**Message transmission channel:** A means of transferring a client's request to perform a financial operation (money transfer) which requires a remote access to payment instruments. Examples of message transmission channels include SMS messages, USSD requests, batch communication (GPRS, EDGE, 3G data, HSDPA, etc.). + +**Payment instrument:** A set of legal measures to perform a remittance, both cash and non-cash, for the purpose of making a payment. Examples of payment instruments include bank accounts, operator accounts and bank cards. + +**Available operations:** A list of operations available in the system of a certain security level. + +**Restrictions:** Limitations for using the system as provided by the accepted risk model that are legally stated or reserved in mutual contracts. + +**Predefined phone:** A phone number previously indicated by the client in a special form of the service provider. + +**Ad hoc phone:** A phone number indicated by the client directly when making a payment. + +**Predefined account:** An account number previously indicated by the client in a special form of the service provider. + +**Ad hoc account:** An account number indicated by the client directly when making a payment. + +**Predefined payment:** A payment made under previously provided parameters where a payment recipient can be selected from the list defined by the MPS service provider (e.g., payment made by an individual person to a corporate entity for the provided services). + +**Ad hoc payment:** A payment made by the client for the services that are not included in the list defined by the MPS service provider on condition that making such payment is technically realizable. Precondition: it is obligatory that either the service provider should have a channel to interoperate with the MPS provider or the service should be provided by another MPS provider and interoperation should be established between the two. + +**Automatic payment:** A regular and automatic payment initiated by the MPS service provider with the prior client's consent. + +**Automatic payment with confirmation:** A regular and automatic payment initiated by the MPS service provider with the client's consent. + +**Payment initiated by merchant:** A payment whose parameters are determined and entered by the merchant. The client can either confirm or reject processing the offered payment. + +**Information service:** A range of information services provided by the MPS system provider that are not associated with conducting financial operations (e.g., viewing a payment instrument balance, providing reference information). + +### **Mobile banking and mobile commerce systems implementation models** + +Possible models of the mobile banking and mobile commerce systems subject to the implementation of the security levels are covered below. Each implementation model imposes certain requirements on payment instrument, available operations, restrictions and application used in the system. + +### **II.1 The implementation of the system without the use of the client application** + +It corresponds to level 1 and level 2 of the system security (see [ITU-T Y.2740]). + +**Message transmission channel:** Plain text SMS messages, USSD requests, + +**Payment instrument:** Payments from bank accounts and operator accounts predefined in the service agreement. + +**Available operations:** Payments are made only to recipients previously defined in the contract. A list of possible operations should be specified when signing a contract: + +- Payment for a predefined phone; +- Payment into a predefined account; +- Making a predefined payment; +- Making automatic payments; +- Making automatic payments with confirmation; +- Information service. + +**Restrictions:** Maximum payment limits which may include transaction amount limits, intraday transaction limits; restriction on available financial transactions which implies payments only for previously agreed services. + +### **II.2 The implementation of the system with the use of the client application** + +It corresponds to level 3 and level 4 of the system security (see [ITU Y.2740]). + +**Message transmission channel:** SMS messages, batch communication (GPRS, EDGE, 3G data, HSDPA, etc.). The message transmission channel and the message being transmitted must be encrypted using strong cryptography. + +**Payment instrument:** Payments from bank and operator accounts predefined in the service agreement, payments using bank cards as well as the cards of international payment systems (payments include the transmission of critical data over the communications channels). + +**Available operations:** Remote connection to the system is possible; a wide range of payments for various services connected to the system; the possibility to considerably increase the number of operations implemented within the MPS (introducing new payments and services; connecting new merchants); the list of available payments can be flexibly defined by both the service provider and the client; different MPS can interoperate in providing services. The following operations are possible to be implemented: + +- Payment for a predefined phone; +- Payment into a predefined account; +- Making a predefined payment; +- Making automatic payments; +- Making automatic payments with confirmation; +- Information service; +- Payment for an ad hoc phone; + +- Payments into an ad hoc account; +- Ad hoc payments; +- Payments initiated by a merchant. + +**Restrictions:** Restrictions on payments are determined in the mutual contracts of the system participants. + +**Application:** Using the application is obligatory to provide security (encryption of messages) as well as convenient system usage. + +# **Bibliography** + +[b-ITU-T Y.2001] Recommendation ITU-T Y.2001 (2004), *General overview of NGN*. + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|--------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Terminals and subjective and objective assessment methods | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/Y/T-REC-Y.2775-201908-I_PDF-E/raw.md b/marked/Y/T-REC-Y.2775-201908-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..d891a75d6c9dbaf8956dc56b414244279e6a4d88 --- /dev/null +++ b/marked/Y/T-REC-Y.2775-201908-I_PDF-E/raw.md @@ -0,0 +1,956 @@ + + +I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +## Y.2775 + +(08/2019) + +SERIES Y: GLOBAL INFORMATION +INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS, +NEXT-GENERATION NETWORKS, INTERNET OF +THINGS AND SMART CITIES + +Next Generation Networks – Security + +# --- **Functional architecture of deep packet inspection for future networks** + +Recommendation ITU-T Y.2775 + +## ITU-T Y-SERIES RECOMMENDATIONS + +## GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS, NEXT-GENERATION NETWORKS, INTERNET OF THINGS AND SMART CITIES + +## GLOBAL INFORMATION INFRASTRUCTURE + +| | | +|-------------------------------------------|-------------| +| General | Y.100–Y.199 | +| Services, applications and middleware | Y.200–Y.299 | +| Network aspects | Y.300–Y.399 | +| Interfaces and protocols | Y.400–Y.499 | +| Numbering, addressing and naming | Y.500–Y.599 | +| Operation, administration and maintenance | Y.600–Y.699 | +| Security | Y.700–Y.799 | +| Performances | Y.800–Y.899 | + +## INTERNET PROTOCOL ASPECTS + +| | | +|--------------------------------------------------------------------|---------------| +| General | Y.1000–Y.1099 | +| Services and applications | Y.1100–Y.1199 | +| Architecture, access, network capabilities and resource management | Y.1200–Y.1299 | +| Transport | Y.1300–Y.1399 | +| Interworking | Y.1400–Y.1499 | +| Quality of service and network performance | Y.1500–Y.1599 | +| Signalling | Y.1600–Y.1699 | +| Operation, administration and maintenance | Y.1700–Y.1799 | +| Charging | Y.1800–Y.1899 | +| IPTV over NGN | Y.1900–Y.1999 | + +## NEXT GENERATION NETWORKS + +| | | +|-------------------------------------------------------------------|---------------| +| Frameworks and functional architecture models | Y.2000–Y.2099 | +| Quality of Service and performance | Y.2100–Y.2199 | +| Service aspects: Service capabilities and service architecture | Y.2200–Y.2249 | +| Service aspects: Interoperability of services and networks in NGN | Y.2250–Y.2299 | +| Enhancements to NGN | Y.2300–Y.2399 | +| Network management | Y.2400–Y.2499 | +| Network control architectures and protocols | Y.2500–Y.2599 | +| Packet-based Networks | Y.2600–Y.2699 | + +## **Security Y.2700–Y.2799** + +| | | +|--------------------------------|---------------| +| Generalized mobility | Y.2800–Y.2899 | +| Carrier grade open environment | Y.2900–Y.2999 | + +## FUTURE NETWORKS + +| | +|---------------| +| Y.3000–Y.3499 | +|---------------| + +## CLOUD COMPUTING + +| | +|---------------| +| Y.3500–Y.3999 | +|---------------| + +## INTERNET OF THINGS AND SMART CITIES AND COMMUNITIES + +| | | +|---------------------------------------------------------|---------------| +| General | Y.4000–Y.4049 | +| Definitions and terminologies | Y.4050–Y.4099 | +| Requirements and use cases | Y.4100–Y.4249 | +| Infrastructure, connectivity and networks | Y.4250–Y.4399 | +| Frameworks, architectures and protocols | Y.4400–Y.4549 | +| Services, applications, computation and data processing | Y.4550–Y.4699 | +| Management, control and performance | Y.4700–Y.4799 | +| Identification and security | Y.4800–Y.4899 | +| Evaluation and assessment | Y.4900–Y.4999 | + +For further details, please refer to the list of ITU-T Recommendations. + +# Recommendation ITU-T Y.2775 + +# Functional architecture of deep packet inspection for future networks + +## Summary + +Recommendation ITU-T Y.2775 specifies the functional architecture of deep packet inspection (DPI) for future networks (e.g., software-defined networking, network function virtualization). This Recommendation specifies general DPI functional architecture aspects related to future networks, DPI functional architecture for software-defined networking, DPI functional architecture for network function virtualization, DPI functional architecture for service function chaining and DPI as a service, DPI functional architecture for network virtualization and DPI functional architecture for evolving mobile network. + +## History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|----------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T Y.2775 | 2019-08-13 | 13 | 11.1002/1000/13983 | + +## Keywords + +Deep packet inspection, functional architecture, future networks. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. For example, . + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2019 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | | Page | +|----|-------------------------------------------------------------------------------------------------------|------| +| 1 | Scope..... | 1 | +| 2 | References..... | 1 | +| 3 | Definitions ..... | 1 | +| | 3.1 Terms defined elsewhere..... | 1 | +| | 3.2 Terms defined in this Recommendation..... | 2 | +| 4 | Abbreviations and acronyms ..... | 2 | +| 5 | Conventions ..... | 4 | +| 6 | General DPI functional architecture for future networks ..... | 4 | +| 7 | DPI functional architecture for SDN ..... | 5 | +| | 7.1 Overview of software-defined networking..... | 5 | +| | 7.2 General functional architecture of DPI for SDN ..... | 6 | +| | 7.3 Functional model for DPI-PEF and PFF within a physical entity in the
SDN context ..... | 8 | +| | 7.4 Functional model for DPI-PEF and PFF within different physical entity in
the SDN context ..... | 8 | +| | 7.5 Functional model for bidirectional DPI in the SDN context..... | 9 | +| 8 | DPI functional architecture for network function virtualization ..... | 11 | +| | 8.1 Overview of NFV ..... | 11 | +| | 8.2 General model of DPI for NFV ..... | 12 | +| | 8.3 Functional architecture for vDPI ..... | 13 | +| 9 | DPI functional architecture for service function chaining and DPI as a service ..... | 15 | +| | 9.1 Overview of service function chaining..... | 15 | +| | 9.2 Introduction of DPI as a service ..... | 16 | +| | 9.3 DPI functional architecture for DPIaaS in service function chaining ..... | 16 | +| | 9.4 DPI functional architecture for extended DPI as a service..... | 17 | +| 10 | DPI functional architecture in network virtualization environment ..... | 18 | +| | 10.1 Overview of network virtualization..... | 18 | +| | 10.2 DPI functional architecture for network virtualization ..... | 19 | +| 11 | DPI functional architecture for evolving mobile networks ..... | 22 | +| | 11.1 Introduction of evolving mobile networks ..... | 22 | +| | 11.2 General information for evolving mobile networks ..... | 22 | +| | 11.3 DPI applied in evolving mobile network..... | 23 | +| | 11.4 Specification of DPI functions in evolving mobile networks ..... | 24 | +| | 11.5 Example DPI functional architecture for IMT-2020 ..... | 25 | +| 12 | Security and other considerations ..... | 25 | +| | Bibliography..... | 26 | + + + +# Recommendation ITU-T Y.2775 + +# Functional architecture of deep packet inspection for future networks + +# 1 Scope + +This Recommendation specifies the functional architecture of deep packet inspection (DPI) for future networks (e.g., software-defined networking, network function virtualization). The scope of this Recommendation includes: + +- general DPI functional architecture aspects related to future networks; +- DPI functional architecture for software-defined networking; +- DPI functional architecture for network function virtualization; +- DPI functional architecture for service function chaining and DPI as a service; +- DPI functional architecture for network virtualization; +- DPI functional architecture for evolving mobile network. + +Implementers and users of these described techniques shall comply with all applicable national and regional laws, regulations and policies. The mechanisms described in this Recommendation may not be applicable to the international correspondence in order to ensure the secrecy and sovereign national legal requirements placed upon telecommunications, but they shall comply with the ITU Constitution and Convention. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- [ITU-T X.200] Recommendation ITU-T X.200 (1994) | ISO/IEC 7498-1 (1994), *Information technology – Open Systems Interconnection – Basic Reference Model: The basic model*. +- [ITU-T Y.2704] Recommendation ITU-T Y.2704 (2010), *Security mechanisms and procedures for NGN*. +- [ITU-T Y.2770] Recommendation ITU-T Y.2770 (2012), *Requirements of deep packet inspection in next generation networks*. +- [ITU-T Y.2771] Recommendation ITU-T Y.2771 (2014), *Framework for deep packet inspection*. +- [ITU-T Y.3011] Recommendation ITU-T Y.3011 (2012), *Framework of network virtualization for future networks*. +- [ITU-T Y.3300] Recommendation ITU-T Y.3300 (2015), *Framework of software-defined networking*. + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 deep packet inspection (DPI)** [ITU-T Y.2770]: Analysis, according to the layered protocol architecture OSI-BRM [ITU-T X.200], of + +- payload and/or packet properties (see list of potential properties in clause 3.2.11 of [ITU-T Y.2770]) deeper than protocol layer 2, 3 or 4 (L2/L3/L4) header information, and +- other packet properties + +in order to identify the application unambiguously. + +NOTE – The output of the DPI function, along with some extra information such as the flow information, is typically used in subsequent functions such as reporting or actions on the packet. + +**3.1.2 DPI analyser** [ITU-T Y.2771]: A subsequent entity in the DPI processing path (within a DPI policy enforcement function) with focus on comparison functions between the particular packet headers and payloads of preselected packet flows. The primary scope of the DPI **analyser** is related to the evaluation of DPI policy *conditions* against *preselected* incoming packets. + +NOTE – The DPI analyser may be located after a DPI scanner (see clause 3.2.5 of [ITU-T Y.2771]). The DPI analyser may provide the functionality of an intrusion detection system (IDS) analyser. + +**3.1.3 DPI engine** [ITU-T Y.2770]: A subcomponent and central part of the DPI functional entity which performs all packet path processing functions (e.g., packet identification and other packet processing functions in Figure 6-1 of [ITU-T Y.2770]). + +**3.1.4 DPI node** [ITU-T Y.2771]: A network element or device that realizes the DPI related functions. It is thus a generic term used to designate the realization of a DPI physical entity. + +NOTE – Functional perspective: the DPI node function (DPI-NF) comprises the DPI policy enforcement function (DPI-PEF) and the (optional) local policy decision function (L-PDF), hence, the DPI-NF is functionally equal to the DPI functional entity. + +**3.1.5 future network (FN)** [b-ITU-T Y.3001]: A network able to provide services, capabilities, and facilities difficult to provide using existing network technologies. A future network is either: + +- a) A new component network or an enhanced version of an existing one, or +- b) A heterogeneous collection of new component networks or of new and existing component networks that is operated as a single network. + +**3.1.6 metadata** [b-IETF RFC 7665]: Provides the ability to exchange context information between classifiers and SFs, and among SFs. + +**3.1.7 service function (SF)** [b-ITU-T Y Suppl. 41]: A function, specifically representing network service function, that is responsible for specific treatment of received packets other than the normal, standard functions of an IP router (e.g., IP forwarding and routing functions) on the network path between a source host and destination host. + +NOTE – The examples of service function are similar to, but not limited to that of a middlebox. + +**3.1.8 service function chain** [b-ITU-T Y Suppl. 41]: A chain that defines an ordered set of abstract service functions and ordering constraints that must be applied to packets and/or frames and/or flows selected as a result of classification and/or policy. + +**3.1.9 service function chaining** [b-ITU-T Y Suppl. 41]: A mechanism of building service function chains and forwarding packets/frames/flows through them. + +## **3.2 Terms defined in this Recommendation** + +None. + +# **4 Abbreviations and acronyms** + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|----------|--------------------------------------------------| +| 2G | Second Generation | +| 3G | Third Generation | +| 4G | Fourth Generation | +| 5G | Fifth Generation | +| API | Application Programming Interface | +| BSC | Base Station Controller | +| BTS | Base Transceiver Station | +| DNNF | Determining Next Node Function | +| DPI-AnF | Deep Packet Inspection Analyser Function | +| DPI-AcEF | Deep Packet Inspection Action Execution Function | +| DPI | Deep Packet Inspection | +| DPIaaS | DPI as a Service | +| DPI-NF | DPI Node Function | +| DPI-PEF | DPI Policy Enforcement Function | +| DPI-PDF | DPI Policy Decision Function | +| DPI-PIB | DPI Policy Information Base | +| DPI-ScF | Deep Packet Inspection Scan Function | +| FIB | Forwarding Information Base | +| GGSN | GPRS Support Node | +| GPRS | General Packet Radio Service | +| HSS | Home Subscriber Server | +| IETF | Internet Engineer Task Force | +| IMT | International Mobile Telecommunication | +| IP | Internet Protocol | +| L2 | Layer 2 | +| L3 | Layer 3 | +| L4 | Layer 4 | +| L7 | Layer 7 | +| L-PDF | Local Policy Decision Function | +| LTE | Long Term Evolution | +| MANO | Management and Orchestration | +| MME | Mobile Management Entity | +| NFV | Network Function Virtualization | +| NFVI | Network Function Virtualization Infrastructure | +| NMS | Network Management System | +| NSH | Network Service Header | +| PCRF | Policy and Charging Rules Function | + +| | | +|-------|-----------------------------------| +| PDF | Policy Decision Function | +| PFF | Packet Forwarding Function | +| P-GW | Packet data network Gateway | +| PIB | Policy Information Base | +| QoS | Quality of Service | +| R-PDF | Remote Policy Decision Function | +| RAN | Radio Access Network | +| RNC | Radio Network Controller | +| SaaS | Software as a Service | +| SBC | Session Border Controller | +| SDN | Software-Defined Networking | +| SFC | Service Function Chaining | +| SGSN | Serving GPRS Support Node | +| S-GW | Serving-Gateway | +| TCO | Total Cost of Ownership | +| TDF | Traffic Detection Function | +| VNF | Virtual Network Function | +| VGW | Virtual Gate Way | +| VMME | Virtual Machine Management Entity | +| vDPI | virtual Deep Packet Inspection | + +# 5 Conventions + +In the body of this Recommendation, the words shall and should may sometimes appear, in which case they are to be interpreted, respectively, as is required to and is recommended. + +# 6 General DPI functional architecture for future networks + +Figure 6-1 depicts a general DPI functional architecture for future networks, and this general DPI functional architecture is based on the general, high-level functional model defined in [ITU-T Y.2771] (see Figure 7-2 of [ITU-T Y.2771]). + +There are two parts in the packet node, the DPI node function (DPI-NF) and the packet forwarding function (PFF). The DPI-NF comprises the DPI policy enforcement function (DPI-PEF) and the local-policy decision function (L-PDF). Hence, the DPI-NF is functionally equal to the DPI functional entity; The PFF comprises the determining next node function (DNMF) and the forwarding information base (FIB). + +As shown in Figure 6-1, the packet flow passes through the DPI-PEF first and then enters the DNMF. In the DPI-PEF, the packet flow is processed by two stages. The first stage is the evaluation of policy conditions which is aimed for the packet flow identification. The second stage is the evaluation of policy actions, in which the packet flow is handled and transferred to the PFF. + +A DPI functional architecture should be designed coincidentally with other different types of network architectures. As a result, in the DPI-NF, there are some external interfaces to exchange information with other entities: DPI policy decision function entity [ITU-T Y.2770], or other policy decision + +function entities (e.g., network controller). The external interfaces are allowed to make appropriate changes depending on the specific requirements of future networks. + +The architecture described in Figure 6-1 is a basic DPI functional architecture for future networks and the architecture shall be modified if it is needed to match different types of network architecture. + +![Figure 6-1: General DPI functional architecture for future networks. The diagram shows a 'Packet node' containing a 'DPI node function (DPI-NF)' and a 'Packet forwarding function (PFF)'. The 'DPI node function' includes a 'DPI policy enforcement function (DPI-PEF)' which contains a 'DPI policy information base (DPI-PIB)'. The 'DPI-PIB' feeds into 'Stage 1: Evaluation of policy conditions' and 'Stage 2: Evaluation of policy actions'. The 'Packet forwarding function' includes a 'Forwarding information base (FIB)' and a 'Determining next node function (DNNF)'. External interfaces connect the 'DPI node function' to 'DPI policy decision function entity' and 'Other policy decision function entity (e.g., network controller)'. A 'Local policy decision function (L-PDF)' is also shown within the 'DPI node function'. A 'Packet flow' enters from the left, passing through the stages and then to the 'Determining next node function' before exiting to the right.](e9314c83043183351ed74908e9bf2f90_img.jpg) + +Y.2775(19)\_F6-1 + +Figure 6-1: General DPI functional architecture for future networks. The diagram shows a 'Packet node' containing a 'DPI node function (DPI-NF)' and a 'Packet forwarding function (PFF)'. The 'DPI node function' includes a 'DPI policy enforcement function (DPI-PEF)' which contains a 'DPI policy information base (DPI-PIB)'. The 'DPI-PIB' feeds into 'Stage 1: Evaluation of policy conditions' and 'Stage 2: Evaluation of policy actions'. The 'Packet forwarding function' includes a 'Forwarding information base (FIB)' and a 'Determining next node function (DNNF)'. External interfaces connect the 'DPI node function' to 'DPI policy decision function entity' and 'Other policy decision function entity (e.g., network controller)'. A 'Local policy decision function (L-PDF)' is also shown within the 'DPI node function'. A 'Packet flow' enters from the left, passing through the stages and then to the 'Determining next node function' before exiting to the right. + +**Figure 6-1 – General DPI functional architecture for future networks** + +# 7 DPI functional architecture for SDN + +## 7.1 Overview of software-defined networking + +As a typical future network technology or architecture, software-defined networking (SDN) has two basic principles: + +- to create a layered network architecture in which all control functions are separated from network forwarding functions; +- to make networking functions available as programmable resources, via a logically centralized "controller," connected via standardized interfaces (typically application programming interfaces (APIs)) to "applications". Centralization of the controller is a core principle, providing an end-to-end view of the network to users and applications. The above basic principles are described visually in Figure 7-1 (see also Figure 11-1 of [ITU-T Y.3300]). + +![Figure 7-1: High-level architecture of SDN architecture. The diagram shows a vertical stack of layers. On the left, a vertical blue bar is labeled 'Multi-layer management functions'. The main stack consists of three layers: 1. Application layer (top): Contains two green boxes labeled 'Application'. 2. SDN control layer (middle): Contains three green boxes labeled 'Application support', 'Orchestration', and 'Abstraction'. 3. Resource layer (bottom): Contains two green boxes labeled 'Control support' and 'Data transport and processing'. Red dashed lines separate the layers. To the right of the layers, labels indicate interfaces: 'Application-control interface' between the Application and SDN control layers, and 'Resource-control interface' between the SDN control and Resource layers. The label 'Y.2775(19)_F7-1' is at the bottom right.](d4af765160d04ecef538e5066006dc77_img.jpg) + +Figure 7-1: High-level architecture of SDN architecture. The diagram shows a vertical stack of layers. On the left, a vertical blue bar is labeled 'Multi-layer management functions'. The main stack consists of three layers: 1. Application layer (top): Contains two green boxes labeled 'Application'. 2. SDN control layer (middle): Contains three green boxes labeled 'Application support', 'Orchestration', and 'Abstraction'. 3. Resource layer (bottom): Contains two green boxes labeled 'Control support' and 'Data transport and processing'. Red dashed lines separate the layers. To the right of the layers, labels indicate interfaces: 'Application-control interface' between the Application and SDN control layers, and 'Resource-control interface' between the SDN control and Resource layers. The label 'Y.2775(19)\_F7-1' is at the bottom right. + +**Figure 7-1 – High-level architecture of SDN architecture** + +## 7.2 General functional architecture of DPI for SDN + +DPI functions deployed in SDN have different functional architecture from DPI functions deployed in the traditional network ecosystem. + +Application identification is critical for providing visibility, quality of service (QoS), billing, and security. Application-awareness is even more important within SDN. Current SDN APIs are capable of Layer 2/3/4-based policy enforcement but they currently lack higher layer application awareness. Figure 6-1 depicts the general high-level functional architecture of DPI. Figure 7-1 depicts the high-level architecture of SDN. However, this DPI model architecture cannot directly be used in SDN architecture without modifications. + +A DPI node is also a network entity, and it should be designed coincident with the above SDN architecture. + +In SDN context, DPI functions could be deployed in the resource layer, or they could be deployed in both the resource layer and the control layer. The general functional architecture of DPI for SDN is given as Figure 7-2. Figure 7-2 shows that basic DPI functions are implemented in the resource layer, while the DPI policy decision function (DPI-PDF) is implemented in the control layer. + +DPI resource layer implements the basic DPI functions as well as control support functions, and control support functions provide service for the control layer. + +DPI control layer can be divided into three functions: + +- 1) DPI application support function; +- 2) DPI-PDF; +- 3) DPI abstract function. + +DPI application support function is used to connect with the upper application layer, while DPI abstract function can connect the lower resource layer. It is obvious that DPI-PDF is used for policy or rule control. + +The DPI applications (network service, function or entity that is implemented based on DPI functions, e.g., firewalls) are mapped to the application layer of SDN. These DPI applications interact with the control layer via application-control interfaces, in order for the control layer to automatically customize the behaviour and properties of network resources. The programming of a DPI application makes use of the abstracted view of the network resources provided by the control layer via the application-control interface. In reality, the application-control interface is implemented through the DPI application support function. + +The DPI application-support function is the DPI extension of SDN application support which provides application-control interface for DPI applications to access network information and customize DPI-specific network behaviours. + +According to [ITU-T Y.2771], the DPI-PDF includes session dependent PDF ( $S_D$ -PDF) and session independent PDF ( $S_I$ -PDF) which are mapped to the SDN orchestration and multilayer management function, respectively. The DPI-PDF provides the automated control and management of DPI rules and coordination of requests from the DPI applications. DPI-PDF function is one of the core functions of orchestration sublayer of control layer. + +The DPI abstraction function interacts with network resources, and provides an abstraction of the physical and virtual DPI resources in the network, including network DPI capabilities and characteristics (e.g., network topology, DPI-PIB) to support DPI management and orchestration of physical and virtual network resources. + +The DPI L-PDF within the DPI resource layer is mapped to the SDN control support function. The L-PDF interacts with the DPI-PDF function through the DPI abstraction and supports programmability via resource-control interfaces. + +The DPI policy enforcement function (DPI-PEF) is mapped to the SDN data transport and processing function. The DPI-PEF is part of the SDN data-forwarding functionalities. In the DPI-PEF, the packet flow is processed by three serialized functions: + +- 1) DPI scan function (DPI-ScF); +- 2) DPI analyser function (DPI-AnF); and +- 3) DPI action execution function (DPI-AcEF). + +![Figure 7-2: General functional architecture of DPI for SDN. The diagram shows a multi-layer architecture. On the left, a vertical bar represents 'Multi-layer management functions' containing 'DPI S_I-PDF'. The main architecture is divided into three horizontal layers: 1. Application layer: Contains 'Application' and 'DPI application (e.g., firewall)'. 2. SDN control layer: Contains 'Application support' (with 'DPI application support'), 'Orchestration' (with 'DPI S_D-PDF and S_I-PDF'), and 'Abstraction' (with 'DPI abstraction'). 3. Resource layer: Contains 'Control support' (with 'DPI local policy decision function (L-PDF)') and 'Data transport and processing' (with 'DPI policy enforcement function' containing 'DPI PIB', 'DPI scan function (DPI-ScF)', 'DPI analyser function (DPI-AnF)', and 'DPI action execution function (DPI-AcEF)', and 'Packet forward function (PFF)'). Red dashed lines separate the layers, labeled 'Application-control interface' and 'Resource-control interface'. A reference 'Y.2775(19)_F7-2' is at the bottom right.](ddc7460821484f1ae2835c67955c554c_img.jpg) + +Figure 7-2: General functional architecture of DPI for SDN. The diagram shows a multi-layer architecture. On the left, a vertical bar represents 'Multi-layer management functions' containing 'DPI S\_I-PDF'. The main architecture is divided into three horizontal layers: 1. Application layer: Contains 'Application' and 'DPI application (e.g., firewall)'. 2. SDN control layer: Contains 'Application support' (with 'DPI application support'), 'Orchestration' (with 'DPI S\_D-PDF and S\_I-PDF'), and 'Abstraction' (with 'DPI abstraction'). 3. Resource layer: Contains 'Control support' (with 'DPI local policy decision function (L-PDF)') and 'Data transport and processing' (with 'DPI policy enforcement function' containing 'DPI PIB', 'DPI scan function (DPI-ScF)', 'DPI analyser function (DPI-AnF)', and 'DPI action execution function (DPI-AcEF)', and 'Packet forward function (PFF)'). Red dashed lines separate the layers, labeled 'Application-control interface' and 'Resource-control interface'. A reference 'Y.2775(19)\_F7-2' is at the bottom right. + +**Figure 7-2 – General functional architecture of DPI for SDN** + +## 7.3 Functional model for DPI-PEF and PFF within a physical entity in the SDN context + +![Figure 7-3: Model for a physical entity including both PEF and PFF. The diagram shows a Controller connected to a Packet node. The Packet node is divided into two main sections: DPI node function (DPI-NF) and Packet forwarding function (PFF). The DPI node function contains a Local policy decision function (L-PDF) and a DPI policy enforcement function (DPI-PEF). The DPI-PEF contains a DPI policy information base (DPI-PIB) and a sequence of functions: DPI scan function (DPI-ScF), DPI analyser function (DPI-AnF), and DPI action execution function (DPI-AcEF). The Packet forwarding function contains a Forwarding information base (FIB) and a Determining next node function (DNNF). A Packet flow enters the DPI-ScF, moves through the analyser and action execution functions, then to the DNNF, and finally exits the Packet node. The Controller is connected to the DPI-NF and PFF sections.](b9ecbc3baefab13719e000faa6e0c7eb_img.jpg) + +Figure 7-3 illustrates the functional model for a physical entity within an SDN context, integrating both DPI-PEF and PFF. The model is organized into a **Packet node**, which is managed by a **Controller**. + +The **Packet node** is divided into two primary functional areas: + +- DPI node function (DPI-NF)**: This section handles policy enforcement and includes: + - Local policy decision function (L-PDF)**: A dashed box representing local policy decisions. + - DPI policy enforcement function (DPI-PEF)**: A sub-function containing: + - DPI policy information base (DPI-PIB)**: A green box that provides policy data to the DPI scan and analyser functions. + - DPI scan function (DPI-ScF)**: The first step in processing the packet flow. + - DPI analyser function (DPI-AnF)**: The second step, analyzing the scanned packet. + - DPI action execution function (DPI-AcEF)**: The third step, executing actions based on the analysis. +- Packet forwarding function (PFF)**: This section handles packet forwarding and includes: + - Forwarding information base (FIB)**: A dashed box representing the database used for forwarding decisions. + - Determining next node function (DNNF)**: A dashed box that determines the next hop for the packet. + +The **Packet flow** enters the **DPI-ScF**, proceeds through the **DPI-AnF** and **DPI-AcEF**, then moves to the **DNNF** in the **PFF** section, and finally exits the **Packet node**. The **Controller** is connected to the **DPI-NF** and **PFF** sections, providing centralized control. + +Y.2775(19)\_F7-3 + +Figure 7-3: Model for a physical entity including both PEF and PFF. The diagram shows a Controller connected to a Packet node. The Packet node is divided into two main sections: DPI node function (DPI-NF) and Packet forwarding function (PFF). The DPI node function contains a Local policy decision function (L-PDF) and a DPI policy enforcement function (DPI-PEF). The DPI-PEF contains a DPI policy information base (DPI-PIB) and a sequence of functions: DPI scan function (DPI-ScF), DPI analyser function (DPI-AnF), and DPI action execution function (DPI-AcEF). The Packet forwarding function contains a Forwarding information base (FIB) and a Determining next node function (DNNF). A Packet flow enters the DPI-ScF, moves through the analyser and action execution functions, then to the DNNF, and finally exits the Packet node. The Controller is connected to the DPI-NF and PFF sections. + +**Figure 7-3 – Model for a physical entity including both PEF and PFF** + +If the DPI function is embedded in a physical network device, then the PEF and PFF are designed in a single physical network. Under such circumstance, a single controller is used to control both PEF and PFF, and Figure 7-3 depicts such a model. + +## 7.4 Functional model for DPI-PEF and PFF within different physical entity in the SDN context + +If the DPI function is deployed as an independent network device, the DPI entity is possible not to include a PFF, in other words, PEF and PFF belongs to different physical network devices. Because of separation of PEF and PFF, either a single controller or double controllers can be used to control the above network devices. + +### 7.4.1 Single-controller model + +Figure 7-4 describes the single-controller mode. Within the above controller, PEF-control function and PFF-control function can be design as independent and mutual-connected logical entities. + +![Figure 7-4: Functional model for PEF and PFF with a single controller. The diagram shows a 'Controller' box at the top containing a 'Coordination function' box, which is connected to two 'PEF-control function' and 'PFF-control function' boxes. Below the controller is the 'DPI policy enforcement function (DPI-PEF)' box, which contains a 'DPI policy information base (DPI-PIB)' box and a flow of three boxes: 'DPI scan function (DPI-ScF)' → 'DPI scan function (DPI-ScF)' → 'DPI action execution function (DPI-AcEF)'. To the right is the 'Packet forwarding function (PFF)' box, which contains a dashed 'Forwarding information base (FIB)' box and a dashed 'Determining next node function (DNMF)' box. Arrows show data flow from an input to the DPI-PEF, from DPI-PIB to the scan functions, from the scan functions to the action execution function, and from the action execution function to the PFF. The PFF then outputs. A label 'Y.2775(19)_F7-4' is at the bottom right.](33ed1f9b27c7c21c797aa928b0f06851_img.jpg) + +Figure 7-4: Functional model for PEF and PFF with a single controller. The diagram shows a 'Controller' box at the top containing a 'Coordination function' box, which is connected to two 'PEF-control function' and 'PFF-control function' boxes. Below the controller is the 'DPI policy enforcement function (DPI-PEF)' box, which contains a 'DPI policy information base (DPI-PIB)' box and a flow of three boxes: 'DPI scan function (DPI-ScF)' → 'DPI scan function (DPI-ScF)' → 'DPI action execution function (DPI-AcEF)'. To the right is the 'Packet forwarding function (PFF)' box, which contains a dashed 'Forwarding information base (FIB)' box and a dashed 'Determining next node function (DNMF)' box. Arrows show data flow from an input to the DPI-PEF, from DPI-PIB to the scan functions, from the scan functions to the action execution function, and from the action execution function to the PFF. The PFF then outputs. A label 'Y.2775(19)\_F7-4' is at the bottom right. + +**Figure 7-4 – PEF and PFF belong to different physical entities with single controller** + +### 7.4.2 Double-controller model + +Figure 7-5 describes the double-controller mode. Controller-PEF and Controller-PFF should cooperate to realize the control functions of the related physical devices. + +![Figure 7-5: Functional model for PEF and PFF with different controllers. The diagram shows two separate controller boxes at the top: 'Controller-PEF' and 'Controller-PFF'. 'Controller-PEF' is connected to the 'DPI policy enforcement function (DPI-PEF)' box, which contains a 'DPI policy information base (DPI-PIB)' box and a flow of three boxes: 'DPI scan function (DPI-ScF)' → 'DPI scan function (DPI-ScF)' → 'DPI action execution function (DPI-AcEF)'. 'Controller-PFF' is connected to the 'Packet forwarding function (PFF)' box, which contains a dashed 'Forwarding information base (FIB)' box and a dashed 'Determining next node function (DNMF)' box. Arrows show data flow from an input to the DPI-PEF, from DPI-PIB to the scan functions, from the scan functions to the action execution function, and from the action execution function to the PFF. The PFF then outputs. A label 'Y.2775(19)_F7-5' is at the bottom right.](75f0cb39f1cd165dfe4a6aa6c4d9388d_img.jpg) + +Figure 7-5: Functional model for PEF and PFF with different controllers. The diagram shows two separate controller boxes at the top: 'Controller-PEF' and 'Controller-PFF'. 'Controller-PEF' is connected to the 'DPI policy enforcement function (DPI-PEF)' box, which contains a 'DPI policy information base (DPI-PIB)' box and a flow of three boxes: 'DPI scan function (DPI-ScF)' → 'DPI scan function (DPI-ScF)' → 'DPI action execution function (DPI-AcEF)'. 'Controller-PFF' is connected to the 'Packet forwarding function (PFF)' box, which contains a dashed 'Forwarding information base (FIB)' box and a dashed 'Determining next node function (DNMF)' box. Arrows show data flow from an input to the DPI-PEF, from DPI-PIB to the scan functions, from the scan functions to the action execution function, and from the action execution function to the PFF. The PFF then outputs. A label 'Y.2775(19)\_F7-5' is at the bottom right. + +**Figure 7-5 – PEF and PFF belong to different physical entities with different controller** + +## 7.5 Functional model for bidirectional DPI in the SDN context + +### 7.5.1 General functional model for bidirectional DPI + +A general bidirectional DPI functional model is depicted in Figure 7-6. Without losing generalization, the two independent DPI nodes cooperate to handle the bidirectional traffic. One of them handles a direction of packet traffic, while the other controls another direction of packet traffic. Meanwhile a network management system (NMS) server can manage the above DPI nodes if there are logical links between the NMS server and the DPI nodes. + +![Figure 7-6: General DPI bidirectional DPI functional model. This diagram illustrates a network architecture where traffic flows from left to right through a central cloud. On the left, traffic enters from a group of computers, passes through a switch, and then through a DPI node. On the right, traffic exits from a group of computers, passes through a switch, and then through another DPI node. The two DPI nodes are connected to a central cloud. Above the cloud, a dashed purple diamond shape represents 'DPI functions'. Below the cloud, the label 'DPI node' is present. The entire diagram is labeled 'Traffic' at both the entry and exit points. The reference 'Y.2775(19)_F7-6' is located at the bottom right.](fa859e4e468bfb2710a94527f2c504af_img.jpg) + +Figure 7-6: General DPI bidirectional DPI functional model. This diagram illustrates a network architecture where traffic flows from left to right through a central cloud. On the left, traffic enters from a group of computers, passes through a switch, and then through a DPI node. On the right, traffic exits from a group of computers, passes through a switch, and then through another DPI node. The two DPI nodes are connected to a central cloud. Above the cloud, a dashed purple diamond shape represents 'DPI functions'. Below the cloud, the label 'DPI node' is present. The entire diagram is labeled 'Traffic' at both the entry and exit points. The reference 'Y.2775(19)\_F7-6' is located at the bottom right. + +**Figure 7-6 – General DPI bidirectional DPI functional model** + +### 7.5.2 Single-controller functional model for bidirectional DPI in SDN context + +In SDN context, the bidirectional DPI functional model is basically different. The single-controller functional model for bidirectional DPI in SDN context is introduced first, and Figure 7-7 describes the above single-controller functional model. + +If the two DPI nodes that cooperate to realization the bidirectional DPI functions can be controlled by an identical controller, then single-controller functional model can be used. + +In Figure 7-7, a single controller controls the two DPI nodes while NMS server manages the above DPI nodes through the above controller. + +![Figure 7-7: Single-controller bidirectional DPI functional model in SDN context. This diagram shows a network architecture similar to Figure 7-6, but with a single controller. The traffic flows from left to right through a central cloud. On the left, traffic enters from a group of computers, passes through a switch, and then through a DPI node. On the right, traffic exits from a group of computers, passes through a switch, and then through another DPI node. The two DPI nodes are connected to a central cloud. Above the cloud, a dashed purple diamond shape represents 'DPI functions'. Below the cloud, the label 'DPI node' is present. A single 'Controller' is shown at the top, connected to both DPI nodes. An 'NMS' server is also shown at the top, connected to the Controller. The entire diagram is labeled 'Traffic' at both the entry and exit points. The reference 'Y.2775(19)_F7-7' is located at the bottom right.](41a438d7e4adc17c3a4005e7c9500091_img.jpg) + +Figure 7-7: Single-controller bidirectional DPI functional model in SDN context. This diagram shows a network architecture similar to Figure 7-6, but with a single controller. The traffic flows from left to right through a central cloud. On the left, traffic enters from a group of computers, passes through a switch, and then through a DPI node. On the right, traffic exits from a group of computers, passes through a switch, and then through another DPI node. The two DPI nodes are connected to a central cloud. Above the cloud, a dashed purple diamond shape represents 'DPI functions'. Below the cloud, the label 'DPI node' is present. A single 'Controller' is shown at the top, connected to both DPI nodes. An 'NMS' server is also shown at the top, connected to the Controller. The entire diagram is labeled 'Traffic' at both the entry and exit points. The reference 'Y.2775(19)\_F7-7' is located at the bottom right. + +**Figure 7-7 – Single-controller bidirectional DPI functional model in SDN context** + +### 7.5.3 Multi-controller functional model for bidirectional DPI in SDN context + +The multi-controller functional model for bidirectional DPI in SDN context is theoretically different from the single-controller functional model that is described in clause 7.5.2, and Figure 7-8 describes the above multi-controller functional model. + +If the two DPI nodes that cooperate to realization the bidirectional DPI functions are controlled by different controllers, then multi-controller functional model can be used. + +In Figure 7-8, two controllers control the two DPI nodes respectively. Meanwhile, a NMS server manages the above DPI nodes through the above two controllers. In addition, the two controllers can exchange information (e.g., information about topology and information about policy rule) if needed. + +![Figure 7-8: Multi-controller bidirectional DPI functional model in SDN context. The diagram illustrates a network architecture where traffic flows from left to right. On the left, traffic enters through a switch and a router. It then passes through a 'DPI node' (represented by a cloud) and another router/switch before exiting on the right. Two 'Controller' units are connected to the routers and the central cloud. An 'NMS' (Network Management System) is connected to both controllers. Dashed arrows indicate bidirectional communication between the controllers and the DPI node. The label 'Y.2775(19)_F7-8' is located at the bottom right of the diagram.](8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg) + +Figure 7-8: Multi-controller bidirectional DPI functional model in SDN context. The diagram illustrates a network architecture where traffic flows from left to right. On the left, traffic enters through a switch and a router. It then passes through a 'DPI node' (represented by a cloud) and another router/switch before exiting on the right. Two 'Controller' units are connected to the routers and the central cloud. An 'NMS' (Network Management System) is connected to both controllers. Dashed arrows indicate bidirectional communication between the controllers and the DPI node. The label 'Y.2775(19)\_F7-8' is located at the bottom right of the diagram. + +**Figure 7-8 – Multi-controller bidirectional DPI functional model in SDN context** + +# **8 DPI functional architecture for network function virtualization** + +## **8.1 Overview of NFV** + +Network function virtualization (NFV) is network technology or architecture which is much different from the current network. + +NFV aims to decouple software from hardware and virtualizes network functions so they do not have to depend on special hardware, and new functions and services can be deployed through software installation and upgrades. NFV helps carriers increase network flexibility, realize highly efficient network construction and operation, expedite service provisioning, and reduce total cost of ownership (TCO). + +It is learned that NFV envisages the implementation of network functions (NFs) as software-only entities that run over the NFV infrastructure (NFVI) from [b-NFV-Framework]. Figure 8-1 (see also Figure 1 of [b-NFV-Framework]) illustrates the high-level NFV framework. As such, three main working domains are identified in NFV: + +- 1) virtualised network function, as the software implementation of a network function which is capable of running over the NFVI; +- 2) NFVI, including the diversity of physical resources and how these can be virtualised. NFVI gives support for implementation of various VNFs; +- 3) NFV management and orchestration (MANO), which covers the orchestration and lifecycle management of physical and/or software resources that support the infrastructure virtualisation, and the lifecycle management of VNFs. + +NFV MANO focuses on all virtualisation-specific management tasks necessary in the NFV framework. + +![Figure 8-1 – High-level NFV framework diagram. The diagram shows a layered architecture. At the top is a box labeled 'Virtualized network functions (VNFs)' containing five 'VNF' blocks. Below this is the 'NFV infrastructure (NFVI)' box, which contains a 'Virtualization layer' box. Inside the virtualization layer are three boxes: 'Virtual compute', 'Virtual storage', and 'Virtual network'. Below the virtualization layer are three boxes: 'Compute', 'Storage', and 'Network'. At the bottom is a box labeled 'Hardware resources'. To the right of the NFVI box is a large box labeled 'NFV management and orchestration'. The reference 'Y.2775(19)_F8-1' is at the bottom right.](76b0cd79baaedd942af4dc42f2e764b8_img.jpg) + +Figure 8-1 – High-level NFV framework diagram. The diagram shows a layered architecture. At the top is a box labeled 'Virtualized network functions (VNFs)' containing five 'VNF' blocks. Below this is the 'NFV infrastructure (NFVI)' box, which contains a 'Virtualization layer' box. Inside the virtualization layer are three boxes: 'Virtual compute', 'Virtual storage', and 'Virtual network'. Below the virtualization layer are three boxes: 'Compute', 'Storage', and 'Network'. At the bottom is a box labeled 'Hardware resources'. To the right of the NFVI box is a large box labeled 'NFV management and orchestration'. The reference 'Y.2775(19)\_F8-1' is at the bottom right. + +**Figure 8-1 – High-level NFV framework** + +## 8.2 General model of DPI for NFV + +### 8.2.1 Traditional DPI vs DPI in NFV context + +Traditionally, DPI functions can be deployed in the current network through several different ways. One of the typical DPI deployments for current network is embedding the DPI functions into various network devices such as session border controller (SBC), traffic detection function (TDF) and gateway general packet radio service (GPRS) support node (GGSN), etc. The main disadvantage of this deployment is that high costs will be incurred by implementing DPI functions on different hardware platforms and interworking between different applications is more difficult. The left half of Figure 8-2 describes the above deployment mode. Nevertheless, the aforementioned disadvantage should be paid attention to. + +It is much different for DPI functions to be deployed in an NFV-based network. In NFV context, DPI functions can be transited from various network devices into which the DPI functions are embedded to the standard server and become common-build function blocks which are executed in VMs. The right side of Figure 8-2 depicts this deployment mode. + +NOTE – Based on this deployment mode, cost and power consumption can be reduced and the interworking between different applications can be implemented more flexibly. + +![Figure 8-2 – Deployment mode for traditional DPI and DPI in NFV diagram. The left side shows three physical server racks labeled 'Session border controller (SBC)', 'Traffic detection function (TDF)', and 'Gateway GPRS support node (GGSN)'. Below them is a box labeled 'DPI-engine' with lines connecting to each of the three racks. A large green arrow points from this traditional setup to the right. The right side shows a virtualized setup. A large green box contains four columns labeled 'SBC', 'TDF', 'GGSN', and 'vDPI-engine'. Below this box are four dashed boxes labeled 'VM'. Below the VMs is a box labeled 'Server' with a person icon next to it. The reference 'Y.2775(19)_F8-2' is at the bottom right.](77464a47f104d0d647b2414591137b64_img.jpg) + +Figure 8-2 – Deployment mode for traditional DPI and DPI in NFV diagram. The left side shows three physical server racks labeled 'Session border controller (SBC)', 'Traffic detection function (TDF)', and 'Gateway GPRS support node (GGSN)'. Below them is a box labeled 'DPI-engine' with lines connecting to each of the three racks. A large green arrow points from this traditional setup to the right. The right side shows a virtualized setup. A large green box contains four columns labeled 'SBC', 'TDF', 'GGSN', and 'vDPI-engine'. Below this box are four dashed boxes labeled 'VM'. Below the VMs is a box labeled 'Server' with a person icon next to it. The reference 'Y.2775(19)\_F8-2' is at the bottom right. + +**Figure 8-2 – Deployment mode for traditional DPI and DPI in NFV** + +### 8.2.2 Functional model for DPI in NFV context + +Figure 8-3 describes a general functional model of DPI in NFV context. Within NFV context, a DPI node (DPI entity) can be seen as a virtual network entity named virtual DPI (vDPI) just like virtual gateway (VGW) or virtual machine management entity (VMME) in NFV. + +Similar to a physical network entity, a vDPI can receive and transmit data packets from other network entities or from the other network. After packets enter the vDPI, they will be processed by the core functional component, vDPI-engine. As shown in Figure 8-3, the vDPI-engine also has three subfunction components: DPI-ScF, DPI-AnF and DPI-AcEF. After being processed by the vDPI, packets will be transmitted to the PFF to be further processed. + +In the course of packet processing, a vDPI node can either apply a pre-defined policy directly or send this information to a network entity (e.g., an outside controller or a management entity) or a network application which can implement the remote policy decision functions, and then receive the policies or rules. In this way, the L-PDF should have the ability to exchange the information with NFV manager and NMS such as EMS. + +![Figure 8-3: Deployment mode for traditional DPI and DPI for NFV. The diagram illustrates the functional architecture of a vDPI within an NFV context. At the top, 'Network operation (OSS/BSS)' connects to 'EMS' (Element Management System). The 'vDPI' is shown as a 'Virtualized network function' containing an 'L-PDF' (Local Policy Decision Function) and an 'L-PEF' (Local Policy Enforcement Function). The 'L-PEF' contains a 'DPI-PIB' (DPI Policy Information Base) which feeds into a 'cDPI-engine' (core DPI engine). The 'cDPI-engine' consists of three sub-components: 'DPI-ScF' (DPI Service Chain Function), 'DPI-AnF' (DPI Analysis Function), and 'DPI-AcEF' (DPI Action Enforcement Function). The output of the 'cDPI-engine' goes to a 'Packet forwarding function (PFF)' which contains a 'FIB' (Forwarding Information Base) and a 'DNNF' (Distributed Network Network Function). The 'PFF' connects to the 'NFV infrastructure' at the bottom, which is composed of 'Virtual resources', 'Virtualization layer', and 'Hardware resources'. The 'NFV infrastructure' also connects to the 'NFV manager and orchestration' block on the right, which includes an 'Orchestrator', 'VNF manager(s)', and 'Virtualized infrastructure manager(s)'. Red arrows indicate 'Policy control' and 'Packet flows'.](10781f43062bf3e9601a1e086710556c_img.jpg) + +Y.2775(19)\_F8-3 + +Figure 8-3: Deployment mode for traditional DPI and DPI for NFV. The diagram illustrates the functional architecture of a vDPI within an NFV context. At the top, 'Network operation (OSS/BSS)' connects to 'EMS' (Element Management System). The 'vDPI' is shown as a 'Virtualized network function' containing an 'L-PDF' (Local Policy Decision Function) and an 'L-PEF' (Local Policy Enforcement Function). The 'L-PEF' contains a 'DPI-PIB' (DPI Policy Information Base) which feeds into a 'cDPI-engine' (core DPI engine). The 'cDPI-engine' consists of three sub-components: 'DPI-ScF' (DPI Service Chain Function), 'DPI-AnF' (DPI Analysis Function), and 'DPI-AcEF' (DPI Action Enforcement Function). The output of the 'cDPI-engine' goes to a 'Packet forwarding function (PFF)' which contains a 'FIB' (Forwarding Information Base) and a 'DNNF' (Distributed Network Network Function). The 'PFF' connects to the 'NFV infrastructure' at the bottom, which is composed of 'Virtual resources', 'Virtualization layer', and 'Hardware resources'. The 'NFV infrastructure' also connects to the 'NFV manager and orchestration' block on the right, which includes an 'Orchestrator', 'VNF manager(s)', and 'Virtualized infrastructure manager(s)'. Red arrows indicate 'Policy control' and 'Packet flows'. + +**Figure 8-3 – Deployment mode for traditional DPI and DPI for NFV** + +## 8.3 Functional architecture for vDPI + +Generally, in NFV context, a vDPI entity is carried out by one or more VM, in other words, vDPI functions are mapped into one or more VNFs. + +There are several typical functional architectures for mapping between vDPI entities and VMs, in other words, mapping between vDPI functions and VNFs. + +### 8.3.1 Single VMs implements a vDPI entity + +This is the simplest and general method to realize vDPI entities, the entire vDPI entity is implemented by a single VM. Figure 8-4 describes the method where a single VM implements a vDPI entity. + +![Figure 8-4: A single VM implements a vDPI entity. The diagram shows a hierarchical structure within a light blue box labeled 'vDPI (realized by single VM)'. At the top is an orange box 'L-PDF'. Below it is a green box 'L-PEF'. Inside 'L-PEF' is a white box 'DPI-PIB'. Below 'DPI-PIB' is a white box 'vDPI-engine'. Inside 'vDPI-engine' are three white boxes: 'DPI-ScF', 'DPI-AnF', and 'DPI-AcEF'. Arrows show a flow from 'DPI-PIB' to 'DPI-ScF', 'DPI-AnF', and 'DPI-AcEF'. There is also an arrow from 'DPI-ScF' to 'DPI-AnF', and from 'DPI-AnF' to 'DPI-AcEF'. The label 'Y.2775(19)_F8-4' is at the bottom right.](5445597cceefaca1ac89e710fe339325_img.jpg) + +Y.2775(19)\_F8-4 + +Figure 8-4: A single VM implements a vDPI entity. The diagram shows a hierarchical structure within a light blue box labeled 'vDPI (realized by single VM)'. At the top is an orange box 'L-PDF'. Below it is a green box 'L-PEF'. Inside 'L-PEF' is a white box 'DPI-PIB'. Below 'DPI-PIB' is a white box 'vDPI-engine'. Inside 'vDPI-engine' are three white boxes: 'DPI-ScF', 'DPI-AnF', and 'DPI-AcEF'. Arrows show a flow from 'DPI-PIB' to 'DPI-ScF', 'DPI-AnF', and 'DPI-AcEF'. There is also an arrow from 'DPI-ScF' to 'DPI-AnF', and from 'DPI-AnF' to 'DPI-AcEF'. The label 'Y.2775(19)\_F8-4' is at the bottom right. + +Figure 8-4 – A single VM implements a vDPI entity + +### 8.3.2 Multiple VMs implement a vDPI entity and a single VM implements a vDPI-engine + +This is the typical distributed method to realize the vDPI entities, the vDPI entity is realized by several VMs, while the vDPI-engine is carried out by a single VM. Figure 8-5 describes this method. In Figure 8-5, three VMs are used to realize a vDPI entity. VM1-VM3 can be designed in the identical physical machine or different physical machines. + +![Figure 8-5: Multiple VMs realize a vDPI entity while a single VM realizes a vDPI-engine. The diagram shows a hierarchical structure within a light blue box labeled 'vDPI (realized by single VM)'. At the top is an orange box 'L-PDF (VM1)'. Below it is a green box 'L-PEF'. Inside 'L-PEF' is a white box 'DPI-PIB (VM2)'. Below 'DPI-PIB (VM2)' is a white box 'vDPI-engine (VM3)'. Inside 'vDPI-engine (VM3)' are three white boxes: 'DPI- ScF', 'DPI-AnF', and 'DPI-AcEF'. Arrows show a flow from 'DPI-PIB (VM2)' to 'DPI- ScF', 'DPI-AnF', and 'DPI-AcEF'. There is also an arrow from 'DPI- ScF' to 'DPI-AnF', and from 'DPI-AnF' to 'DPI-AcEF'. The label 'Y.2775(19)_F8-5' is at the bottom right.](2eb23c2210154279f8013a1594fbcc5a_img.jpg) + +Y.2775(19)\_F8-5 + +Figure 8-5: Multiple VMs realize a vDPI entity while a single VM realizes a vDPI-engine. The diagram shows a hierarchical structure within a light blue box labeled 'vDPI (realized by single VM)'. At the top is an orange box 'L-PDF (VM1)'. Below it is a green box 'L-PEF'. Inside 'L-PEF' is a white box 'DPI-PIB (VM2)'. Below 'DPI-PIB (VM2)' is a white box 'vDPI-engine (VM3)'. Inside 'vDPI-engine (VM3)' are three white boxes: 'DPI- ScF', 'DPI-AnF', and 'DPI-AcEF'. Arrows show a flow from 'DPI-PIB (VM2)' to 'DPI- ScF', 'DPI-AnF', and 'DPI-AcEF'. There is also an arrow from 'DPI- ScF' to 'DPI-AnF', and from 'DPI-AnF' to 'DPI-AcEF'. The label 'Y.2775(19)\_F8-5' is at the bottom right. + +Figure 8-5 – Multiple VMs realize a vDPI entity while a single VM realizes a vDPI-engine + +### 8.3.3 Multiple VMs implement a vDPI entities and multiple VMs implement a vDPI-engine + +This is the appropriate method to realize the vDPI entities with the best extensibility and flexibility. When using this method, the vDPI entity is realized by several coordinated VMs, in addition, the vDPI-engine is also implemented by multiple coordinated VMs. Moreover, the DPI-ScF, DPI-AnF and DPI-AcEF are also carried out by multiple coordinated VMs. Figure 8-6 describes this method. In Figure 8-6, The DPI-ScF is realized by VM3-VMi, The DPI-AnF is realized by VMi-VMj, and the DPI-AcEF is realized by VMj-VMk. VM1-VMk can be designed in the identical physical machine or different physical machines. + +![Figure 8-6: Multiple VMs realize a vDPI entity. The diagram shows a hierarchical structure. At the top is a box labeled 'vDPI (realized by single VM)'. Inside this box is an orange box labeled 'L-PDF (VM1)'. Below 'L-PDF (VM1)' is a green box labeled 'L-PEF'. Inside 'L-PEF' is a white box labeled 'DPI-PIB (VM2)'. Below 'DPI-PIB (VM2)' is a white box labeled 'vDPI-engine'. Inside 'vDPI-engine' are three boxes: 'DPI- ScF (VM3-i)', 'DPI-AnF (VMi-j)', and 'DPI-AcEF (VMj-k)'. Arrows show a flow from 'DPI- ScF (VM3-i)' to 'DPI-AnF (VMi-j)' to 'DPI-AcEF (VMj-k)'. Additionally, an arrow points from 'DPI-PIB (VM2)' to 'DPI- ScF (VM3-i)'. The text 'Y.2775(19)_F8-6' is at the bottom right of the diagram.](5b8a756d9a71c35f17db8bcb90b438a3_img.jpg) + +Figure 8-6: Multiple VMs realize a vDPI entity. The diagram shows a hierarchical structure. At the top is a box labeled 'vDPI (realized by single VM)'. Inside this box is an orange box labeled 'L-PDF (VM1)'. Below 'L-PDF (VM1)' is a green box labeled 'L-PEF'. Inside 'L-PEF' is a white box labeled 'DPI-PIB (VM2)'. Below 'DPI-PIB (VM2)' is a white box labeled 'vDPI-engine'. Inside 'vDPI-engine' are three boxes: 'DPI- ScF (VM3-i)', 'DPI-AnF (VMi-j)', and 'DPI-AcEF (VMj-k)'. Arrows show a flow from 'DPI- ScF (VM3-i)' to 'DPI-AnF (VMi-j)' to 'DPI-AcEF (VMj-k)'. Additionally, an arrow points from 'DPI-PIB (VM2)' to 'DPI- ScF (VM3-i)'. The text 'Y.2775(19)\_F8-6' is at the bottom right of the diagram. + +**Figure 8-6 – Multiple VMs realize a vDPI entity meanwhile multiple VMs realize a vDPI-engine** + +# **9 DPI functional architecture for service function chaining and DPI as a service** + +## **9.1 Overview of service function chaining** + +Service function chaining (SFC) is a new network architecture under research in Internet Engineer Task Force (IETF) [b-IETF RFC 7665]. It is an emerging set of technologies and methods that enable operators to configure network services dynamically in software without having to make changes to the infrastructure of the network. Service function chaining is also called service chaining. + +A service function chain defines an ordered or partially ordered set of abstract service functions (SFs) and their ordering constraints that must be applied to packets, frames, and/or flows selected as a result of classification. Figure 9-1 depicts a basic functional architecture of service function chain. There are three important parts of the architecture: + +- 1) classifier: the ability to identify and then classify traffic in order to direct flows into a service function chain is critical. There are several ways to do this: + - simply directing any traffic to; + - from a particular destination to a particular service path; + - a more sophisticated policy-driven scheme. + +In the SFC architecture, there is specifically the packet header definitions: the network service header (NSH). The NSH can carry metadata for managing the chain. Control plane and NSH are basic and important components of SFC architecture; + +- 2) control plane: the SFC control plane includes a topology server and a policy decision point. The topology server talks to the ingress and egress nodes (the classifiers) and locates service function nodes in the network. The policy decision point communicates with the service functions and is a central control/management plane entity used to maintain SFC policy tables; +- 3) NSH: a service-level data plane encapsulation format (i.e., a new packet header) that specifies the sequence of service functions that make up a service chain. This header format can also be used to communicate context information between nodes that implement service functions. + +![Figure 9-1 – Service chaining architecture diagram. The diagram shows a Control plane at the top, connected to two Classifier blocks (left and right) and three Service function nodes (1, 2, and 3) in the middle. The Control plane has bidirectional arrows to each Classifier and each Service function node. The NSH (Network Service Header) block is positioned between Service function node 1 and Service function node 2, with arrows pointing to both. The Service function nodes are connected in a chain: Classifier (left) to Service function node 1, Service function node 1 to NSH, NSH to Service function node 2, Service function node 2 to Service function node 3, and Service function node 3 to Classifier (right).](e69b9188aa2c14ec6b21c83f711fef65_img.jpg) + +Y.2775(19)\_F9-1 + +Figure 9-1 – Service chaining architecture diagram. The diagram shows a Control plane at the top, connected to two Classifier blocks (left and right) and three Service function nodes (1, 2, and 3) in the middle. The Control plane has bidirectional arrows to each Classifier and each Service function node. The NSH (Network Service Header) block is positioned between Service function node 1 and Service function node 2, with arrows pointing to both. The Service function nodes are connected in a chain: Classifier (left) to Service function node 1, Service function node 1 to NSH, NSH to Service function node 2, Service function node 2 to Service function node 3, and Service function node 3 to Classifier (right). + +**Figure 9-1 – Service chaining architecture** + +At the ingress to the service function chain, a classifier identifies and classifies traffic before forwarding it into the processing path. The path itself is set up and managed by the control plane. + +Network service plays a major role in contemporary networks, as forwarding packets is often not enough to meet operator demands, and other functionalities (such as security, QoS/QoE provisioning, and load balancing) are required. Traffic is usually routed through a service chain, which either resides across the network or in a single, consolidated location. + +## 9.2 Introduction of DPI as a service + +Although a vast range of different capabilities can be provided based on service function chaining, there are some functions or functional entities that can be shared among service functions. + +DPI is a typical function common to almost all service functions included in a service function chain. DPI can deal with protocols from layer 2 (L2) to layer 7 (L7). Generally, network traffic needs to be scanned and analysed from beginning to end by all service functions of the service function chain. In other words, if there are two or more service functions in the service function chain, the network traffic is possibly scanned and analysed twice or more. However, the duplication of service functions scanning and analysing identical traffic twice or more can be avoided by deploying the DPI function in DPI as a service (DPIaaS) mode. + +DPIaaS can be thought of as implementing DPI functions in software as a service (SaaS) mode, similar to how other functions are implemented in an SaaS mode. DPIaaS implements DPI functions in the cloud and provides the aforementioned functions to clients that need those functions. In the service chain context, DPIaaS implies that traffic can be scanned and analysed only once and that the scanning and analysis results of DPIaaS can meet the requirements of all service functions in the service chain. The DPI service thus passes the scanning and analysis results to all appropriate service function instances. Deploying the DPI service in this way has significant advantages in performance, scalability and robustness, and is a catalyst for innovation in the service chaining domain. + +## 9.3 DPI functional architecture for DPIaaS in service function chaining + +Figure 9-2 describes a typical architecture of DPIaaS in a service chain. This architecture requires a DPI controller and one or more DPI service nodes providing the DPI service for the service node in service chaining. All service nodes can make direct use of the scanning and analysis results from the DPI service node without reiterating the DPI's function of scanning and analysing packets. + +In this manner, the network could avoid repeating DPI-related functions. It is thus possible to decrease network resource consumption as well as improve utilization of network devices and functions. + +The DPI controller is a logically centralized entity whose role is to control the DPI functions across the network and to communicate with the SDN controller to realize the appropriate data plane actions. Logically, the DPI controller can reside at the SDN application layer on top of the SDN controller (see Figure 9-2), or the DPI controller can also be a component of SDN controller (i.e., in + +Figure 9-2, the DPI controller can be merged with the SDN controller). Physically, the DPI controller and the SDN controller can optionally be designed within an identical physical device. + +![Figure 9-2: DPIaaS in service chaining. The diagram shows a hierarchical and sequential architecture. At the top, a 'DPI controller' box is connected to an 'SDN controller' box. Below them, a sequence of four boxes is shown: 'DPI service node', followed by three 'Service node' boxes. 'IP packets' enter from the left into the 'DPI service node'. Between the 'DPI service node' and the first 'Service node', and between each subsequent 'Service node', there is a thick black arrow labeled 'DPI scanned result'. Dashed lines connect the 'SDN controller' to each of the four boxes in the sequence. A label 'Y.2775(19)_F9-2' is located at the bottom right of the diagram.](365b54f616aff249b4e6c0edafdcb9b3_img.jpg) + +Figure 9-2: DPIaaS in service chaining. The diagram shows a hierarchical and sequential architecture. At the top, a 'DPI controller' box is connected to an 'SDN controller' box. Below them, a sequence of four boxes is shown: 'DPI service node', followed by three 'Service node' boxes. 'IP packets' enter from the left into the 'DPI service node'. Between the 'DPI service node' and the first 'Service node', and between each subsequent 'Service node', there is a thick black arrow labeled 'DPI scanned result'. Dashed lines connect the 'SDN controller' to each of the four boxes in the sequence. A label 'Y.2775(19)\_F9-2' is located at the bottom right of the diagram. + +**Figure 9-2 – DPIaaS in service chaining** + +Two kinds of procedures take place between the DPI controller and the service nodes, namely: registration and pattern (signature, condition) set management. The first task of the DPI controller is to register service nodes that use its service. Specifically, a service node registers itself to the DPI service using a registration message. The address (e.g., IP address) of the DPI controller and the service node's unique ID and name are preconfigured. + +Generally, the above service node operates by rules that contain actions and conditions that should be matched to activate the actions. The responsibility of the DPI service node is only to scan and analyse packets based upon patterns, while resolving the logic behind a condition and performing the action is the service node's responsibility. The DPI service node only carries out the DPI scanning and analysing function. Patterns are added to and removed from the DPI controller using dedicated messages from service nodes to the DPI controller. The DPI controller maintains a global pattern set with its own internal IDs. If two service nodes register the same pattern (since each has a rule that depends on this pattern), the DPI controller keeps track of each of the rule IDs reported by each service nodes and associates them with its internal ID. For that reason, when a pattern removal request is received, the DPI controller removes the service nodes reference to the corresponding pattern. Only when there are no other service node referrals to that pattern, is the pattern removed. + +Another necessary action is passing the pattern match results to the service nodes. A feasible method is adding match results information as an additional layer of information prior to the packet's payload. This allows maximal flexibility and the best performance. Publicly available frameworks such as NSH may be used to encapsulate match results data in an SDN setting. + +The downside of this approach is that service nodes that refer to the payload on the service chain should be aware of this additional layer of information. However, if all service nodes that use the DPI functions are grouped and placed immediately after the DPI service instance in the service chain, the last service node can simply remove this layer and forward the original packet. + +## 9.4 DPI functional architecture for extended DPI as a service + +DPIaaS can be extended from the service function chain to the general application scenario. Figure 9-3 illustrates an example functional model of extending DPIaaS; the above functional architecture is not limited in service chain domain. Layers are logically classified and all links or relationships between two entities are logical. The DPI part of the model is composed of a DPI + +node, a DPI controller and a DPI service instance. The DPI service instance is a logical abstraction of certain DPI functions, i.e., logical DPI function entities. In the model, the DPI controller abstracts the DPI process to other network elements and controls DPI service instances across the network. The DPI service provided by DPI nodes is responsible for scanning and analysing the packets. As a packet is forwarded, each DPI node on its route retrieves the DPI scanning and analysing results instead of performing the DPI task. Therefore, DPI service instances can be deployed all over the network and DPI service in the model is equivalent to that when DPI nodes are deployed locally to a client using DPI services. + +![Figure 9-3 – DPIaaS framework illustration. The diagram shows a four-layer architecture: Resource layer, Control layer, Access layer, and Client layer. The Resource layer contains a cloud with various network elements, including a 'DPI node' (indicated by a dashed line). The Control layer contains a 'DPI controller' and an 'Other controller'. The Access layer contains three switches. The Client layer contains 'Service node 1', 'Service node 2', an ellipsis, and 'Service node n'. Connections show the DPI controller and other controller managing the DPI node and switches, which in turn connect to the service nodes.](73b5cce955ba9415a98791db7b0080ad_img.jpg) + +Y.2775(19)\_F9-3 + +Figure 9-3 – DPIaaS framework illustration. The diagram shows a four-layer architecture: Resource layer, Control layer, Access layer, and Client layer. The Resource layer contains a cloud with various network elements, including a 'DPI node' (indicated by a dashed line). The Control layer contains a 'DPI controller' and an 'Other controller'. The Access layer contains three switches. The Client layer contains 'Service node 1', 'Service node 2', an ellipsis, and 'Service node n'. Connections show the DPI controller and other controller managing the DPI node and switches, which in turn connect to the service nodes. + +**Figure 9-3 – DPIaaS framework illustration** + +The DPI controller is a logically centralized entity whose role is to control the DPI function or functional entities across the network and to communicate with the other controller to realize the appropriate data plane actions. + +The DPI controller is responsible for registering DPI nodes. DPI nodes operate by rules that contain actions and conditions that should be satisfied to activate the actions. In addition, the DPI controller is also responsible for initializing DPI service instances, deployment of different DPI service instances across the network and for advanced features that require a network-wide view. + +# **10 DPI functional architecture in network virtualization environment** + +## **10.1 Overview of network virtualization** + +Network virtualization is a technology that enables the creation of logically isolated network partitions over shared physical networks such that a heterogeneous collection of multiple virtual networks can simultaneously coexist over shared networks. This includes the aggregation of multiple resources in a provider appearing as a single resource [ITU-T Y.3011]. + +A typical example of network virtualization can be seen in Figure 10-1. In Figure 10-1, a physical network is virtualized to several logical networks (virtual network). Although virtualized logical networks in Figure 10-1 are homogeneous, virtualized logical networks based on the identical physical network can be homogeneous or heterogeneous. + +The relationship between the physical network and the virtual network is not limited to 1:n, and several physical networks can also be virtualized to a virtual network. Mapping between physical networks and virtual networks lies in requirements and design. + +![Figure 10-1: An example of network virtualization. The diagram shows a single physical network at the bottom, which is virtualized into three identical virtual networks at the top. The physical network consists of two routers at the top, connected to two switches, which are then connected to four servers. The three virtual networks are identical copies of this structure, each with its own set of routers, switches, and servers. Dashed arrows indicate the mapping from the physical network to the virtual networks.](552265bdbcf6d43d341fd018a9076269_img.jpg) + +The diagram illustrates network virtualization. At the bottom, a 'Physical network' is shown with two 'ROUTER' nodes at the top, connected to two switch nodes, which are then connected to four server nodes. Above this, three identical 'Virtual network' boxes are shown, each containing a copy of the physical network structure. Dashed arrows point from the physical network to each of the three virtual networks, indicating that the physical network is being virtualized into these logical networks. + +Figure 10-1: An example of network virtualization. The diagram shows a single physical network at the bottom, which is virtualized into three identical virtual networks at the top. The physical network consists of two routers at the top, connected to two switches, which are then connected to four servers. The three virtual networks are identical copies of this structure, each with its own set of routers, switches, and servers. Dashed arrows indicate the mapping from the physical network to the virtual networks. + +**Figure 10-1 – An example of network virtualization** + +## 10.2 DPI functional architecture for network virtualization + +### 10.2.1 Overview of DPI functional architecture for network virtualization + +The general and core feature of a DPI functional architecture for network virtualization is virtualization from physical components to virtual components. If the physical components have been virtualized to the virtual components, logically and functionally, the virtual components are equivalent to the physical components. Thus, mapping physical components to virtual components is the core of DPI functional architecture for network virtualization. + +### 10.2.2 DPI physical components + +A list of DPI-related physical components is listed as follows: + +- DPI nodes; +- DPI engine; +- DPI policy information base (DPI-PIB); +- DPI-ScF; +- DPI-AcF; + +- DPI-AcEF. + +### 10.2.3 DPI virtual components + +Not all DPI physical components can be virtualized, because some of the physical components are not physically independent. + +However, the DPI node, DPI engine and DPI-PIB can be virtualized as a v-DPI node, v-DPI engine and v-DPI-PIB, respectively. + +### 10.2.4 Mapping physical components to virtual components + +There are several methods for mapping physical components to virtual components: 1:n, m:1 and m:n (where m and n are positive integers, and $m > 1$ and $n > 1$ ). + +Figure 10-2 describes the 1:n mode. + +![Figure 10-2: 1:n mapping between physical component and virtual components. The diagram illustrates three levels of virtualization: 1. PIB level: A single physical DPI PIB (represented by a stack of blue and orange disks) is mapped to four virtual v-DPI PIBs (represented by stacks of blue disks). 2. Engine level: A single physical DPI engine (represented by a green circuit board with a chip) is mapped to three virtual v-DPI engines (represented by black chips with yellow pins). 3. Node level: A single physical DPI node (represented by a large blue server rack) is mapped to three virtual v-DPI nodes (represented by smaller blue server racks). Dashed arrows indicate the mapping from one physical component to multiple virtual components.](20136850feb70fd71c7d41cdae203ebb_img.jpg) + +Y.2775(19)\_F10-2 + +Figure 10-2: 1:n mapping between physical component and virtual components. The diagram illustrates three levels of virtualization: 1. PIB level: A single physical DPI PIB (represented by a stack of blue and orange disks) is mapped to four virtual v-DPI PIBs (represented by stacks of blue disks). 2. Engine level: A single physical DPI engine (represented by a green circuit board with a chip) is mapped to three virtual v-DPI engines (represented by black chips with yellow pins). 3. Node level: A single physical DPI node (represented by a large blue server rack) is mapped to three virtual v-DPI nodes (represented by smaller blue server racks). Dashed arrows indicate the mapping from one physical component to multiple virtual components. + +**Figure 10-2 – 1:n mapping between physical component and virtual components** + +Figure 10-3 describes the m:1 mode. + +![Diagram illustrating m:1 mapping between physical components and virtual components. It shows three levels of abstraction: PIBs, engines, and nodes. At the top, four blue and orange cylinders representing 'DPI PIB' are mapped via dashed arrows to two dark blue cylinders representing 'v-DPI PIB'. In the middle, two green circuit boards representing 'DPI engine' are mapped via dashed arrows to one black chip representing 'v-DPI engine'. At the bottom, two large blue server racks representing 'DPI node' are mapped via dashed arrows to one smaller blue server rack representing 'v-DPI node'. The label 'Y.2775(19)_F10-3' is located below the v-DPI node label.](aaf3e6e44cdeabd6d1df869c5f392ea1_img.jpg) + +DPI PIB + +v-DPI PIB + +DPI engine + +v-DPI engine + +DPI node + +v-DPI node +Y.2775(19)\_F10-3 + +Diagram illustrating m:1 mapping between physical components and virtual components. It shows three levels of abstraction: PIBs, engines, and nodes. At the top, four blue and orange cylinders representing 'DPI PIB' are mapped via dashed arrows to two dark blue cylinders representing 'v-DPI PIB'. In the middle, two green circuit boards representing 'DPI engine' are mapped via dashed arrows to one black chip representing 'v-DPI engine'. At the bottom, two large blue server racks representing 'DPI node' are mapped via dashed arrows to one smaller blue server rack representing 'v-DPI node'. The label 'Y.2775(19)\_F10-3' is located below the v-DPI node label. + +**Figure 10-3 – m:1 mapping between physical components and virtual component** + +Figure 10-4 describes the m:n mode. + +![Figure 10-4: m:n mapping between physical components and virtual components. The diagram illustrates the mapping from physical components to virtual components in three layers: PIB, engine, and node. In the top layer, four physical DPI PIBs (two blue, two orange) map to four virtual v-DPI PIBs (all blue). In the middle layer, two physical DPI engines (green circuit boards) map to three virtual v-DPI engines (black chips). In the bottom layer, two physical DPI nodes (blue server racks) map to three virtual v-DPI nodes (blue server racks). Dashed arrows indicate the mapping relationships.](8c348bf9c2c81b018017ae1d19506a9a_img.jpg) + +Y.2775(19)\_F10-4 + +Figure 10-4: m:n mapping between physical components and virtual components. The diagram illustrates the mapping from physical components to virtual components in three layers: PIB, engine, and node. In the top layer, four physical DPI PIBs (two blue, two orange) map to four virtual v-DPI PIBs (all blue). In the middle layer, two physical DPI engines (green circuit boards) map to three virtual v-DPI engines (black chips). In the bottom layer, two physical DPI nodes (blue server racks) map to three virtual v-DPI nodes (blue server racks). Dashed arrows indicate the mapping relationships. + +**Figure 10-4 m:n mapping between physical components and virtual components** + +# **11 DPI functional architecture for evolving mobile networks** + +## **11.1 Introduction of evolving mobile networks** + +Evolution of mobile networks refers to the process where mobile networks are updated to a new generation. For example, when the second generation (2G) mobile network is updated to the third generation (3G) mobile network, that can be called a kind of evolution. + +Therefore, an evolving mobile network is one where the mobile network is developing to a new-generation mobile network with the development of related technologies. For example, the current mobile network has been evolving to a fourth generation (4G) mobile network and will evolve to a fifth generation (5G), and so on, in the future. + +## **11.2 General information for evolving mobile networks** + +The development of mobile networks is very rapid, and at present, mobile networks have evolved from 2G to 3G, and then from 3G to 4G and so on. To be certain, mobile networks will continually be evolving. Figure 11-1 depicts the evolving process and the main differences among mobile networks of 2G, 3G and long-term evolution (LTE). + +It is certain that huge changes related to mobile networks have taken place during this evolving process. Then related technologies applied in mobile networks should also change with the change of the network. + +![Figure 11-1: An example model of evolving mobile network. The diagram shows a vertical timeline on the left with labels 2G, 3G, and LTE, and an arrow pointing downwards. In the 2G section, a BTS (Base Transceiver Station) is connected to a BSC (Base Station Controller). In the 3G section, a Node B is connected to an RNC (Radio Network Controller). In the LTE section, an eNodeB is connected to an MME (Mobility Management Entity). The BSC is connected to the RNC, which is connected to the MME. The RNC is also connected to an SGSN (Serving GPRS Support Node). The SGSN is connected to the MME and the S-GW (Serving Gateway). The MME is connected to the S-GW. The S-GW is connected to the P-GW (PDN Gateway). The P-GW is connected to the HSS (Home Subscriber Server) and the PCRF (Policy and Charging Rules Function). The P-GW is also connected to the PSTN (Public Switched Telephone Network) and the Internet. The HSS and PCRF are connected to the P-GW. The PSTN and Internet are represented by cloud icons. The diagram is labeled Y.2775(19)_F11-1 at the bottom right.](69b7bd65e85cdef6fdd7fb0a8194257c_img.jpg) + +Figure 11-1: An example model of evolving mobile network. The diagram shows a vertical timeline on the left with labels 2G, 3G, and LTE, and an arrow pointing downwards. In the 2G section, a BTS (Base Transceiver Station) is connected to a BSC (Base Station Controller). In the 3G section, a Node B is connected to an RNC (Radio Network Controller). In the LTE section, an eNodeB is connected to an MME (Mobility Management Entity). The BSC is connected to the RNC, which is connected to the MME. The RNC is also connected to an SGSN (Serving GPRS Support Node). The SGSN is connected to the MME and the S-GW (Serving Gateway). The MME is connected to the S-GW. The S-GW is connected to the P-GW (PDN Gateway). The P-GW is connected to the HSS (Home Subscriber Server) and the PCRF (Policy and Charging Rules Function). The P-GW is also connected to the PSTN (Public Switched Telephone Network) and the Internet. The HSS and PCRF are connected to the P-GW. The PSTN and Internet are represented by cloud icons. The diagram is labeled Y.2775(19)\_F11-1 at the bottom right. + +BSC – base station controller + BTS – base transceiver station + HSS – home subscriber server + MME – mobility management entity + PCRF – policy and charging rules function + P-GW – packet data network gateway + PSTN – public switched telephone network + RNC – radio network controller + SGSN – serving GPRS support node + S-GW – serving gateway + +**Figure 11-1 – An example model of evolving mobile network** + +## 11.3 DPI applied in evolving mobile network + +Deep packet inspection technology is a widely used network technology, and it is also widely applied in mobile networks. Figure 11-2 represents a current mobile network deployed with DPI functions (it can be realized by a DPI component or by a single DPI node). + +It can be shown from Figure 11-2 that DPI functions can be deployed in four modes: + +- 1) within radio access network (RAN); +- 2) at the access edge of packet-based core network; +- 3) within packet-based core network; +- 4) at the uplink edge of packet-based core network. + +It should be noted that the above four deployment modes are not mutually exclusive. + +![Figure 11-2 – An example deployment of evolving mobile network supported DPI functions](a2dcc4a0703102026ec86e82caa4985e_img.jpg) + +``` + +graph TD + subgraph 2G + BTS2G[BTS] --> BSC + end + subgraph 3G + NodeB[Node B] --> RNC + end + subgraph LTE + eNodeB --> MME + eNodeB --> SGW[S-GW] + end + BSC --> SGSN + RNC --> SGSN + RNC --> SGW + MME --> SGW + SGSN --> SGW + SGW --> PGW[P-GW] + PGW --> PSTN + PGW --> Internet + + DPI((DPI)) -.-> SGW + DPI -.-> PGW + HSS --- SGW + PCRF --- PGW + +``` + +Detailed description: The diagram shows three generations of mobile access networks: 2G (BTS to BSC), 3G (Node B to RNC), and LTE (eNodeB to MME and S-GW). These connect into a core network consisting of SGSN, S-GW, and P-GW. DPI functions are shown as logical entities connected via dashed lines to the S-GW and P-GW. Small magnifying glass icons indicate potential DPI inspection points at various interfaces: between RNC/SGSN and S-GW, between MME and S-GW, and at the output of the P-GW towards PSTN and the Internet. + +Figure 11-2 – An example deployment of evolving mobile network supported DPI functions + + BSC – base station controller + BTS – base transceiver station + HSS – home subscriber server + MME – mobility management entity + PCRF – policy and charging rules function + P-GW – packet data network gateway + PSTN – public switched telephone network + RNC – radio network controller + SGSN – serving GPRS support node + S-GW – serving gateway + +**Figure 11-2 – An example deployment of evolving mobile network supported DPI functions** +**11.4 Specification of DPI functions in evolving mobile networks** +**11.4.1 Implementing the DPI functions in the single logical level** + +In Figure 11-2, the mobile network can be divided into four logical levels: RAN, access edge of packet-based core network, within packet-based core network and the uplink edge of packet-based core network. Implementing DPI functions in a single logical level means that DPI functions shall be carried out only in that one single logical level. Thus, DPI functions can be deployed according to to the following mode: + +- within the RAN; +- at the access edge of packet-based core network; +- within the packet-based core network; +- at the uplink edge of packet-based core network. + +**11.4.2 Implementing DPI functions in the hierarchical mode** + +Implementing DPI functions in a hierarchical mode means that DPI functions can be deployed in two or more logical levels but with collaboration between DPI functions deployed in the different logical levels. + +For example, if DPI function, R, is deployed in the logical level RAN and DPI function, S, is deployed in the logical level access edge of packet-based core network, then the results of DPI function R should be used by DPI function S. + +24 Rec. ITU-T Y.2775 (08/2019) + +### 11.4.3 Implementing DPI functions in the distribution mode + +Implementing DPI functions in a distributed mode means that it is possible that some DPI components are deployed in the logical level, A, while some other DPI components are deployed in the logical level, B. All of the DPI components distributed in different logical levels cooperate to realize the functions of a DPI node. + +For example, it is possible the DPI-Scf is deployed in the RAN, the DPI-Anf is deployed within the packet-based core network and the DPI-AceF is deployed at the uplink edge of packet-based core network. + +## 11.5 Example DPI functional architecture for IMT-2020 + +At present, the mobile network is evolving to International Mobile Telecommunication (IMT)-2020. Figure 11-3 is an example of the reference model in the G Forum 2016 5G white paper [b-5Gforum-WP]. It is intended to provide a common understanding on what a reference model looks like. + +Figure 11-3 also depicts an example DPI functional architecture for IMT-2020. As illustrated, the DPI in IMT-2020 is deployed in stand-alone and distributed models, the DPI-PDF is located in the core network, while the DPI PEF is located in the devices and access networks. + +![Figure 11-3: An example DPI functional architecture for IMT-2020. The diagram shows three main sections: Devices, Access network, and Core network. The Devices section includes a 'DPI PEF' box and a 'Device' box containing 'D-GW' and 'WSN/USN'. The Access network section includes a 'DPI PEF' box and a large box containing 'MCN (Stand-alone)', 'SCN (Stand-alone)', 'MCN (Radio unit)', 'SCN GW', and 'MCN (Digital unit)'. The Core network section includes a 'DPI PEF' box and a large box containing 'Provisioning', 'Policy', 'C-GW', and 'D-GW'. Connections are shown between these sections: 'Uux' (red dashed line) from Devices to Access network; 'Dux' (dashed line) from Device to Access network; 'X2x' (blue oval) between MCN and SCN in the Access network; 'S1x' (red oval) between SCN GW and Core network; and a connection from D-GW in the Core network to the Internet. A legend at the bottom defines the components: Device: 5G UE (human users), machine devices, moving network nodes (e.g., V2X), infra-less devices, etc.; MCN (macro cell node), SCN (small cell node: e.g., UDN, HotZone, HeNB, etc.); MCN – management communication network; SCN – signalling communication networks; USN – ubiquitous sensor network; WSN – wireless sensor network. The diagram is labeled Y.2775(19)_F11-3.](98e54d5540b2efe3e24af3cf936bc4ea_img.jpg) + +Device: 5G UE (human users), machine devices, moving network nodes (e.g., V2X), infra-less devices, etc. + +MCN (macro cell node), SCN (small cell node: e.g., UDN, HotZone, HeNB, etc.) + +MCN – management communication network +SCN – signalling communication networks +USN – ubiquitous sensor network +WSN – wireless sensor network + +Y.2775(19)\_F11-3 + +Figure 11-3: An example DPI functional architecture for IMT-2020. The diagram shows three main sections: Devices, Access network, and Core network. The Devices section includes a 'DPI PEF' box and a 'Device' box containing 'D-GW' and 'WSN/USN'. The Access network section includes a 'DPI PEF' box and a large box containing 'MCN (Stand-alone)', 'SCN (Stand-alone)', 'MCN (Radio unit)', 'SCN GW', and 'MCN (Digital unit)'. The Core network section includes a 'DPI PEF' box and a large box containing 'Provisioning', 'Policy', 'C-GW', and 'D-GW'. Connections are shown between these sections: 'Uux' (red dashed line) from Devices to Access network; 'Dux' (dashed line) from Device to Access network; 'X2x' (blue oval) between MCN and SCN in the Access network; 'S1x' (red oval) between SCN GW and Core network; and a connection from D-GW in the Core network to the Internet. A legend at the bottom defines the components: Device: 5G UE (human users), machine devices, moving network nodes (e.g., V2X), infra-less devices, etc.; MCN (macro cell node), SCN (small cell node: e.g., UDN, HotZone, HeNB, etc.); MCN – management communication network; SCN – signalling communication networks; USN – ubiquitous sensor network; WSN – wireless sensor network. The diagram is labeled Y.2775(19)\_F11-3. + +**Figure 11-3 – An example DPI functional architecture for IMT-2020** + +# 12 Security and other considerations + +According to [ITU-T Y.2770], the DPI-FE and the information pertaining to DPI operations should be under protection against threats. It shall be guaranteed that information exchanged between remote policy decision function (R-PDF) and L-PDF is accomplished safely. + +The mechanisms specified in [ITU-T Y.2704] address security requirements of this Recommendation. + +Regulations, privacy and security application aspects of DPI are outside the scope of this Recommendation. Vendors, operators and service providers are required to take into account national regulatory and policy requirements when implementing this Recommendation. + +# Bibliography + +- [b-ITU-T Y.3001] Recommendation ITU-T Y.3001 (2011), *Future networks: Objectives and design goals*. +- [b-ITU-T Y Suppl. 41] Recommendation ITU-T Y Suppl. 41 (2016), *ITU-T Y.2200-series - Deployment models of service function chaining*. +- [b-IETF RFC 7665] IETF RFC 7665 (2015), *Service Function Chaining (SFC) Architecture*. +- [b-5Gforum-WP] 5G Technical Study – 2015~2016 5G Technical White paper. +<> +- [b-NFV-Framework] ETSI GS NFV 002 V1.2.1 (2014), *Network function virtualization (NFV) architectural framework*. + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/Y/T-REC-Y.2776-202407-I_PDF-E/raw.md b/marked/Y/T-REC-Y.2776-202407-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..7964d6b4dcf88d89cf0f8dda1ae6873941d26bd4 --- /dev/null +++ b/marked/Y/T-REC-Y.2776-202407-I_PDF-E/raw.md @@ -0,0 +1,918 @@ + + +# Recommendation + +## **ITU-T Y.2776 (07/2024)** + +SERIES Y: Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities + +Next Generation Networks – Security + +--- + +**Deep packet inspection – intelligent management and maintenance of policy information base** + +## ITU-T Y-SERIES RECOMMENDATIONS + +## Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities + +| | | +|-------------------------------------------------------------------|----------------------| +| GLOBAL INFORMATION INFRASTRUCTURE | Y.100-Y.999 | +| INTERNET PROTOCOL ASPECTS | Y.1000-Y.1999 | +| NEXT GENERATION NETWORKS | Y.2000-Y.2999 | +| Frameworks and functional architecture models | Y.2000-Y.2099 | +| Quality of Service and performance | Y.2100-Y.2199 | +| Service aspects: Service capabilities and service architecture | Y.2200-Y.2249 | +| Service aspects: Interoperability of services and networks in NGN | Y.2250-Y.2299 | +| Enhancements to NGN | Y.2300-Y.2399 | +| Network management | Y.2400-Y.2499 | +| Computing power networks | Y.2500-Y.2599 | +| Packet-based Networks | Y.2600-Y.2699 | +| Security | Y.2700-Y.2799 | +| Generalized mobility | Y.2800-Y.2899 | +| Carrier grade open environment | Y.2900-Y.2999 | +| FUTURE NETWORKS | Y.3000-Y.3499 | +| CLOUD COMPUTING | Y.3500-Y.3599 | +| BIG DATA | Y.3600-Y.3799 | +| QUANTUM KEY DISTRIBUTION NETWORKS | Y.3800-Y.3999 | +| INTERNET OF THINGS AND SMART CITIES AND COMMUNITIES | Y.4000-Y.4999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T Y.2776 + +# Deep packet inspection – intelligent management and maintenance of policy information base + +## Summary + +Recommendation ITU-T Y.2776 specifies intelligent management and maintenance aspects for policy information base (PIB) of deep packet inspection (DPI). The scope of this Recommendation includes the following aspects: problem analysis for PIB of DPI; the functional architecture of intelligent management and maintenance of PIB (PIB-IMM); implementation methods for PIB-IMM; functional requirements for PIB-IMM; performance aspects for PIB-IMM; considerations for the control plane of PIB-IMM; consideration for management and application of PIB-IMM; and security considerations. + +## History\* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T Y.2776 | 2024-07-22 | 13 | 11.1002/1000/15894 | + +## Keywords + +Deep packet inspection, intelligent management, policy information base. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed intellectual property right. ITU takes no position concerning the evidence, validity or applicability of claimed intellectual property rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2024 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | | Page | +|----|---------------------------------------------------------------------------------------|------| +| 1 | Scope ..... | 1 | +| 2 | References..... | 1 | +| 3 | Definitions ..... | 2 | +| | 3.1 Terms defined elsewhere..... | 2 | +| | 3.2 Terms defined in this Recommendation..... | 3 | +| 4 | Abbreviations and acronyms ..... | 3 | +| 5 | Conventions ..... | 4 | +| 6 | Problem analysis for policy information base of DPI ..... | 4 | +| 7 | Functional architecture of intelligent management and maintenance of PIB..... | 6 | +| | 7.1 Overview of intelligent management and maintenance of PIB..... | 6 | +| | 7.2 General functional model for intelligent management and maintenance of PIB..... | 6 | +| | 7.3 Basic components necessary for intelligent management and maintenance of PIB..... | 7 | +| | 7.4 Internal interfaces for intelligent management and maintenance of PIB ..... | 8 | +| | 7.5 External interfaces for intelligent management and maintenance of PIB ..... | 8 | +| 8 | Implementation methods for intelligent management and maintenance of PIB..... | 8 | +| | 8.1 Overview of feasible implementation methods..... | 8 | +| | 8.2 Implementation method based on generative adversarial network ..... | 9 | +| | 8.3 Implementation method based on evolving algorithm ..... | 11 | +| | 8.4 Implementation method based on cluster algorithm ..... | 12 | +| | 8.5 Implementation method based on other methods..... | 13 | +| 9 | Functional requirements for intelligent management and maintenance of PIB ..... | 14 | +| | 9.1 Functional requirements for DPI entity ..... | 14 | +| | 9.2 Functional requirements for R-PDF+ ..... | 15 | +| | 9.3 Functional requirements for L-PDF+ ..... | 16 | +| | 9.4 Functional requirements for the DPI-Scf component..... | 16 | +| | 9.5 Functional requirements for the DPI-Anf component..... | 16 | +| | 9.6 Functional requirements for internal interfaces..... | 17 | +| | 9.7 Functional requirements for external interfaces ..... | 17 | +| 10 | Performance aspects for intelligent management and maintenance of PIB ..... | 17 | +| | 10.1 Process time for intelligent management and maintenance of PIB..... | 17 | +| | 10.2 Storage usage for intelligent management and maintenance of PIB..... | 18 | +| | 10.3 Process correct rate for intelligent management and maintenance of PIB ..... | 18 | +| | 10.4 Network traffic awareness correct rate..... | 19 | +| | 10.5 Network traffic awareness volume ..... | 19 | + +| | Page | +|---------------------------------------------------------|-------------| +| 11 Control plane considerations ..... | 19 | +| 11.1 DPI-PIB control plane requirements ..... | 19 | +| 11.2 DPI-PIB control plane considerations ..... | 20 | +| 12 Management and application considerations ..... | 21 | +| 12.1 Overview requirements of management aspect ..... | 21 | +| 12.2 Requirements of management and configuration ..... | 21 | +| 12.3 Requirements of log management ..... | 21 | +| 12.4 Requirements of application ..... | 22 | +| 13 Security considerations ..... | 22 | +| Bibliography ..... | 23 | + +# Recommendation ITU-T Y.2776 + +# Deep packet inspection – intelligent management and maintenance of policy information base + +# 1 Scope + +This Recommendation specifies intelligent management and maintenance aspects for policy information base (PIB) of deep packet inspection (DPI). The scope of this Recommendation includes: + +- a) Problem analysis for PIB of DPI; +- b) Functional architecture of intelligent management and maintenance of PIB; +- c) Implementation methods for intelligent management and maintenance of PIB; +- d) Functional requirements for intelligent management and maintenance of PIB; +- e) Performance aspects for intelligent management and maintenance of PIB; +- f) Consideration for control plane; +- g) Consideration for management and application; +- h) Security consideration. + +Implementers and users of the described techniques shall comply with all applicable national and regional laws, regulations, and policies. The mechanisms described in this Recommendation may not be applicable to international correspondence, in order to ensure the secrecy and sovereign national legal requirements placed upon telecommunication networks, but implementers and users of the mechanisms shall comply with the Constitution and Convention of ITU, such as CS ARTICLE 33. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- [ITU-T X.200] Recommendation ITU-T X.200 (1994) | ISO/IEC 7498-1:1994, *Information technology. Open Systems Interconnection. Basic reference model: The basic model.* +- [ITU-T Y.2704] Recommendation ITU-T Y.2704 (2007), *Security mechanisms and procedures for NGN.* +- [ITU-T Y.2770] Recommendation ITU-T Y.2770 (2012), *Requirements for deep packet inspection in next generation networks.* +- [ITU-T Y.2771] Recommendation ITU-T Y.2771 (2014), *Framework for deep packet inspection.* +- [ITU-T Y.2772] Recommendation ITU-T Y.2772 (2016), *Mechanisms for the network elements with support of deep packet inspection.* +- [ITU-T Y.2773] Recommendation ITU-T Y.2773 (2017), *Performance models and metrics for deep packet inspection.* + +- [ITU-T Y.2774] Recommendation ITU-T Y.2774 (2019), *Functional requirements of deep packet inspection for future networks*. +- [ITU-T Y.2775] Recommendation ITU-T Y.2775 (2019), *Functional architecture of deep packet inspection for future networks*. + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 deep packet inspection (DPI)** [ITU-T Y.2770]: Analysis, according to the layered protocol architecture OSI-BRM [ITU-T X.200], of: + +- payload and/or packet properties (see list of potential properties in clause 3.2.11 of [ITU-T Y.2770]) deeper than protocol layer 2, 3 or 4 (L2/L3/L4) header information, and +- other packet properties; + +in order to identify the application unambiguously. + +NOTE – The output of the DPI function, along with some extra information such as the flow information is typically used in subsequent functions such as reporting or actions on the packet. + +**3.1.2 DPI engine** [ITU-T Y.2770]: A subcomponent and central part of the DPI functional entity which performs all packet path processing functions (e.g., packet identification and other packet processing functions in Figure 6-1 of [ITU-T Y.2770]). + +**3.1.3 DPI policy** [ITU-T Y.2770]: A policy as defined, for example in [b-IETF RFC 3198] (see clause 3.1.4), enforced in a DPI entity. + +**3.1.4 DPI policy condition (also known as DPI signature)** [ITU-T Y.2770]: A representation of the necessary state and/or prerequisites that identify an application and define whether a policy rule's actions should be performed. The set of DPI policy conditions associated with a policy rule specifies when the policy rule is applicable (see also [b-IETF RFC 3198]). + +A DPI policy condition must contain application level conditions and may contain other options such as state conditions and/or flow level conditions: + +- 1) State condition (optional): + - a) network grade of service conditions (e.g., experienced congestion in packet paths); or + - b) network element status (e.g., local overload condition of the DPI-FE). +- 2) Flow descriptor/Flow level conditions (optional): + - a) packet content (header fields); + - b) characteristics of a packet (e.g., number# of MPLS labels); + - c) packet treatment (e.g., output interface of the DPI-FE). +- 3) Application descriptor/application level conditions: + - a) Packet content (application header fields and application payload). + +NOTE – The condition relates to the "simple condition" in the formal descriptions of flow level conditions and application level conditions. + +**3.1.5 DPI policy decision functional entity (DPI-PDFE)** [ITU-T Y.2770]: The function remote to the DPI-FE that decides the signature-based rules to be enforced in the DPI-FE. Some control and/or management functions may not necessarily be remote from the DPI-FE. + +**3.1.6 flow descriptor (also known as flow level conditions)** [ITU-T Y.2770]: A set of rule conditions that is used to identify a specific type of flow (according to clause 3.1.3 of [ITU-T Y.2770]) from inspected traffic. + +NOTE 1 – This definition of flow descriptor extends the definition in [b-ITU-T Y.2121] with additional elements, as described in clause 3 of [ITU-T Y.2770]. + +NOTE 2 – For further normative discussion of the flow descriptor as used in [ITU-T Y.2770], see Annex A of [ITU-T Y.2770]. + +**3.1.7 DPI analyser** [ITU-T Y.2771]: A subsequent entity in the DPI processing path (within a DPI policy enforcement function) with focus on comparison functions between the particular packet headers and payloads of preselected packet flows. The primary scope of the DPI analyser is related to the evaluation of DPI policy conditions against preselected incoming packets. + +NOTE – The DPI analyser may be located after a DPI scanner (see clause 3.2.6). The DPI analyser may provide the functionality of an intrusion detection system (IDS) analyser. + +**3.1.8 DPI node** [ITU-T Y.2771]: A network element or device that realizes the DPI related functions. It is thus a generic term used to designate the realization of a DPI physical entity. + +NOTE – Functional perspective: the DPI node function (DPI-NF) comprises the DPI policy enforcement function (DPI-PEF) and the (optional) local policy decision function (L-PDF); hence, the DPI-NF is functionally equal to the DPI functional entity. + +## 3.2 Terms defined in this Recommendation + +None. + +# 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|----------|--------------------------------------------------| +| AI | Artificial Intelligence | +| CA | Cluster Algorithm | +| CLI | Command Line Interface | +| DL | Deep Learning | +| DPI | Deep Packet Inspection | +| DPI-AcEF | Deep Packet Inspection Action Execution Function | +| DPI-AnF | Deep Packet Inspection Analyser Function | +| DPI-FE | DPI Functional Entity | +| DPI-FMF | DPI Feature Mining Function | +| DPI-PDFE | DPI Policy Decision Functional Entity | +| DPI-PE | DPI Physical Entity | +| DPI-PEF | Policy Enforcement Function | +| DPI-PIB | DPI Policy Information Base | +| DPI-SCF | Deep Packet Inspection Scan Function | +| EA | Evolving Algorithm | +| GAN | Generative Adversarial Network | +| L-IPRG | Local Intelligent Policy Rule Generator | +| L-PDF | Local PDF | + +| | | +|---------|-------------------------------------------------------------------| +| L-PDF+ | L-PDF updated for PIB-IMM | +| MIB | Management Information Base | +| ML | Machine Learning | +| NA | Network Awareness | +| Netconf | Network Configuration | +| NMS | Network Management System | +| NSA | Network Status Awareness | +| NTS | Network Traffic Simulator | +| PDF | Policy Decision Function | +| PIB | Policy Information Base | +| PIB-IMM | Intelligent Management and Maintenance of Policy Information Base | +| QoS | Quality of Service | +| R-IPRG | Remote Intelligent Policy Rule Generator | +| R-PDF | Remote PDF (i.e., PDF remotely located from DPI node perspective) | +| R-PDF+ | R-PDF updated for PIB-IMM | +| SNMP | Simple Network Management Protocol | +| SSH | Secure Shell | +| YANG | Yet Another Next Generation | + +# 5 Conventions + +In this Recommendation: + +The keywords "is required to" indicate a requirement which must be strictly followed and from which no deviation is permitted, if conformance to this Recommendation is to be claimed. + +The keywords "is recommended" indicate a requirement which is recommended but which is not absolutely required. Thus, this requirement need not be present to claim conformance. + +# 6 Problem analysis for policy information base of DPI + +DPI is one of the basic technologies for implementing functions such as application and service awareness. DPI-related technologies and methods are beneficial to network management and control, quality of service (QoS) assurance, network security enhancement, value-added services, and so on. + +At present, DPI-related technologies have been widely applied and played important roles in the network. Improvement and enhancement for DPI-related technologies are necessary anyway. + +[ITU-T Y.2771] has depicted a generic model for the DPI entity, as shown in Figure 6-1. + +![Figure 6-1 – DPI models. This diagram illustrates the architecture of Deep Packet Inspection (DPI) models, divided into Control and Management planes. The Management plane includes General policy management, (DPI) policy management, and a (Session-independent) policy decision function (Si-PDF). The Control plane includes a (Session-dependent) policy decision function (Sd-PDF). The User plane contains the DPI node function, which includes a Local policy decision function (L-PDF) and the DPI policy enforcement function (DPI-PEF). The DPI-PEF contains a DPI policy information base (DPI-PIB) and three sequential functions: DPI scan function (DPI-ScF), DPI analyser function (DPI-AnF), and DPI action execution function (DPI-AcEF). Ingress packet flows enter the DPI-ScF, which sends control information to the DPI-AnF, which in turn sends control information to the DPI-AcEF. The DPI-AcEF sends a Result to the DPI-PIB, which sends Conditions and actions back to the DPI-AnF. The DPI-AnF also sends Conditions and actions to the DPI-ScF. The DPI-AcEF sends data to the Packet forwarding function (PFF), which includes a Forwarding information base (FIB) and a Determining next node function (DNMF). The PFF sends Egress packet flows. Configuration (of DPI policy rules) and Alerts are sent from the Management plane to the L-PDF. A dashed arrow indicates control information flow from the Sd-PDF to the L-PDF via a Policy control interface. A legend shows a dashed arrow with a square head for Control information. A note states: 'NOTE – The PFF is out of the scope of this Recommendation.' Reference: Y.2776(24).](cfef993dcc8fb513de79eb1f93cf26ae_img.jpg) + +Control plane      Management plane + +General policy management +(DPI) policy management +(Session-independent) policy decision function (Si-PDF) + +(Session-dependent) policy decision function (Sd-PDF) + +Policy control interface + +Configuration (of DPI policy rules) + +Alerts + +User plane + +DPI node function + +Local policy decision function (L-PDF) + +Update + +DPI policy enforcement function (DPI-PEF) + +DPI policy information base (DPI-PIB) + +Condition(s) + +Conditions and actions + +Result + +Ingress packet flows + +DPI scan function (DPI-ScF) + +DPI analyser function (DPI-AnF) + +DPI action execution function (DPI-AcEF) + +Packet forwarding function (PFF) + +Forwarding information base (FIB) + +Determining next node function (DNMF) + +Egress packet flows + +■--> Control information + +NOTE – The PFF is out of the scope of this Recommendation. + +Y.2776(24) + +Figure 6-1 – DPI models. This diagram illustrates the architecture of Deep Packet Inspection (DPI) models, divided into Control and Management planes. The Management plane includes General policy management, (DPI) policy management, and a (Session-independent) policy decision function (Si-PDF). The Control plane includes a (Session-dependent) policy decision function (Sd-PDF). The User plane contains the DPI node function, which includes a Local policy decision function (L-PDF) and the DPI policy enforcement function (DPI-PEF). The DPI-PEF contains a DPI policy information base (DPI-PIB) and three sequential functions: DPI scan function (DPI-ScF), DPI analyser function (DPI-AnF), and DPI action execution function (DPI-AcEF). Ingress packet flows enter the DPI-ScF, which sends control information to the DPI-AnF, which in turn sends control information to the DPI-AcEF. The DPI-AcEF sends a Result to the DPI-PIB, which sends Conditions and actions back to the DPI-AnF. The DPI-AnF also sends Conditions and actions to the DPI-ScF. The DPI-AcEF sends data to the Packet forwarding function (PFF), which includes a Forwarding information base (FIB) and a Determining next node function (DNMF). The PFF sends Egress packet flows. Configuration (of DPI policy rules) and Alerts are sent from the Management plane to the L-PDF. A dashed arrow indicates control information flow from the Sd-PDF to the L-PDF via a Policy control interface. A legend shows a dashed arrow with a square head for Control information. A note states: 'NOTE – The PFF is out of the scope of this Recommendation.' Reference: Y.2776(24). + +**Figure 6-1 – DPI models** + +It can be learned from the above figure that policy information base (PIB) is one of the necessary components for the DPI entity and it can be controlled by local policy decision function (L-PDF) or remote policy decision function (R-PDF). Either L-PDF or R-PDF maintains PIB by manual configuration. + +Then, PIB is controlled by L-PDF or R-PDF manually and independent of real-time network traffic. Thus, PIB is static and unchanged within a certain period. However, network traffic is continually changing, especially some harmful network traffic that has the capability to change itself actively in order to escape being checked by DPI-related technologies. Then, DPI based on static PIB is not capable of processing the continually changing network traffic accurately. + +So far, there are several published Recommendations related to DPI. [ITU-T Y.2770] specifies requirements of DPI in next generation network (NGN); [ITU-T Y.2771] specifies the framework of DPI; [ITU-T Y.2772] specifies the mechanism for DPI to be deployed in a network element; + +[ITU-T Y.2773] specifies the performance aspect of DPI; [ITU-T Y.2774] specifies functional requirements of DPI in future networks; and [ITU-T Y.2775] specifies functional architecture of DPI in future networks. + +However, there are not any standards that can clearly describe application features from layer 4 to layer 7. In addition, application features can be changed without any limit. So it is much more difficult for DPI-related technologies to process changing application features. Then, it is helpful to use some technologies that can enhance DPI-related technologies to allow DPI to handle changing application features. + +Currently, artificial intelligence (AI) and machine learning (ML) technologies are rapidly developing and have been applied in various areas. This means that some chances to enhance DPI-related technologies are coming. With the help of ML technologies, PIB can change with the network traffic automatically and real-time PIB can match the real-time network traffic accurately. Thus, however, the network traffic, including active harmful traffic, changes itself, and DPI-related technologies can process such network traffic accurately with the help of the perfectly matched PIB. Then, the capability and performance of DPI can be obviously improved. + +So it is valuable to illustrate how to manage and maintain DPI-PIB intelligently in order to make the real-time PIB match the real-time network traffic accurately. + +# **7 Functional architecture of intelligent management and maintenance of PIB** + +## **7.1 Overview of intelligent management and maintenance of PIB** + +It can be known from clause 6 that PIB of a DPI entity is controlled by L-PDF or R-PDF manually. PIB can be changed only when the control or management entity, for example, the controller or the network management system (NMS), has the capabilities to make L-PDF or R-PDF take such actions. Thus, the modification action of PIB is usually initiated from a control entity (e.g., network controller) or a management entity (e.g., NMS), and the operator of the network entity or the management entity is the real initiator of the modification action. Generally, PIB is static and unchanged within a certain period. + +Different from the aforementioned operation mode of PIB, the initiator of intelligent management and maintenance of PIB is not the network operator but the DPI entity or the DPI control entity itself. Through information collected from the network, the DPI entity or the DPI control entity can operate PIB automatically and intelligently. Then PIB can match the network traffic in a timely way. + +## **7.2 General functional model for intelligent management and maintenance of PIB** + +The general model for intelligent management and maintenance of PIB can be seen in Figure 7-1. This figure is based on the architecture model of traditional DPI described in [ITU-T Y.2771]. In the figure, new functional components are represented by the blue rectangle. In the meantime, L-PDF and R-PDF (see [ITU-T Y.2770] and [ITU-T Y.2771]) are also updated to L-PDF+ and R-PDF+. + +![Figure 7-1: General functional model for intelligent management and maintenance of PIB. The diagram is divided into three planes: Control plane, Management plane, and Data plane. In the Control plane, a Network traffic simulator (NTS) and a Remote intelligent policy rule generator (R-IPRG) are connected by a Policy rule exchange interface. The R-IPRG is connected to an R-PDF+ block. In the Management plane, there is a hierarchy of boxes: General policy management, DPI policy management, and DPI session management. A Policy management interface connects R-PDF+ to DPI policy management. DPI policy management sends DPI policy rules to L-PDF+ in the Data plane. DPI session management sends Report information to DPI policy management. In the Data plane, the DPI entity contains a Local intelligent policy rule generator (L-IPRG) and L-PDF+. They are connected by Rule operation arrows. L-PDF+ sends Rule operation signals to DPI-PIB. DPI-PIB sends Rule and action signals to DPI-FMF. DPI-FMF sends Flow information to L-IPRG. The DPI entity also contains DPI-SCF, DPI-AnF, and DPI-AcEF. DPI-SCF sends data to DPI-AnF, which sends data to DPI-FMF, which then sends data to DPI-AcEF. DPI-PIB also sends data to DPI-SCF. DPI-SCF, DPI-AnF, and DPI-FMF are connected by dashed arrows. DPI-AcEF sends data to the Packet forwarding function (FIB) in the Routing and forwarding block. The Routing and forwarding block sends Traffic egress. A legend indicates that dashed arrows represent Control information.](af7916c89a458fdab6c3f443217388ae_img.jpg) + +■ ---> Control information + +Y.2776(24) + +Figure 7-1: General functional model for intelligent management and maintenance of PIB. The diagram is divided into three planes: Control plane, Management plane, and Data plane. In the Control plane, a Network traffic simulator (NTS) and a Remote intelligent policy rule generator (R-IPRG) are connected by a Policy rule exchange interface. The R-IPRG is connected to an R-PDF+ block. In the Management plane, there is a hierarchy of boxes: General policy management, DPI policy management, and DPI session management. A Policy management interface connects R-PDF+ to DPI policy management. DPI policy management sends DPI policy rules to L-PDF+ in the Data plane. DPI session management sends Report information to DPI policy management. In the Data plane, the DPI entity contains a Local intelligent policy rule generator (L-IPRG) and L-PDF+. They are connected by Rule operation arrows. L-PDF+ sends Rule operation signals to DPI-PIB. DPI-PIB sends Rule and action signals to DPI-FMF. DPI-FMF sends Flow information to L-IPRG. The DPI entity also contains DPI-SCF, DPI-AnF, and DPI-AcEF. DPI-SCF sends data to DPI-AnF, which sends data to DPI-FMF, which then sends data to DPI-AcEF. DPI-PIB also sends data to DPI-SCF. DPI-SCF, DPI-AnF, and DPI-FMF are connected by dashed arrows. DPI-AcEF sends data to the Packet forwarding function (FIB) in the Routing and forwarding block. The Routing and forwarding block sends Traffic egress. A legend indicates that dashed arrows represent Control information. + +**Figure 7-1 – General functional model for intelligent management and maintenance of PIB** + +In Figure 7-1, the blue arrows are also newly added to represent action between two functional components. The solid-line arrows represent necessary actions and the dashed-line arrows represent optional actions. + +It is emphasized that functions for intelligent management and maintenance of PIB can be disabled and enabled by network operators through configuration information. + +## 7.3 Basic components necessary for intelligent management and maintenance of PIB + +There are four new basic functional components that are necessary for implementing the intelligent management and maintenance of PIB, as follows: + +- **DPI feature mining function (DPI-FMF)**: It is a new component of the DPI engine, and it is responsible for collecting network traffic features from the network and submitting those + +features to the other functional components. It can be bypassed if DPI-FMF is not used in some application scenarios. + +- Local intelligent policy rule generator (L-IPRG): It is a functional component within the DPI entity. Its function is to generate useful policy rules based on the network features collected from the other functional components. It can manage and maintain PIB through L-PDF+ (this mode is recommended) or manage and maintain PIB directly (this mode is optional). +- Remote intelligent policy rule generator (R-IPRG): It is a functional component outside of the DPI entity. Its function is the same as the local intelligent policy generators. +- Network traffic simulator (NTS): It is also a functional component outside of the DPI entity. Its function is to generate virtual network traffic in order to facilitate the remote intelligent policy generator. + +## **7.4 Internal interfaces for intelligent management and maintenance of PIB** + +There are six new internal interfaces to be used for intelligent management and maintenance of PIB, as follows: + +- Isr: An interface between the NTS and R-IPRG. This interface is used to input the virtual network traffic or virtual network traffic features (when the network traffic simulator can also support extracting the traffic feature) from the NTS to the R-IPRG. +- Irl: An interface between the R-IPRG and L-IPRG. This interface is used to input policy rules from the R-IPRG to the L-IPRG. +- Irr: An interface between the R-IPRG and R-PDF+. This interface is used to report policy rules, together with the other information from the R-IPRG to R-PDF+. +- Ill: An interface between the L-IPRG and L-PDF+. This interface is used to report policy rules together with the other information from the L-IPRG to L-PDF+. +- Ilp: An interface between the L-IPRG and PIB. This interface is used to configure policy rules from the L-IPRG to PIB. +- Ilf: An interface between the L-IPRG and DPI-FMF. This interface is used to collect network traffic features from DPI-FMF to the L-IPRG. + +## **7.5 External interfaces for intelligent management and maintenance of PIB** + +There is one new external interface needed, as follows: + +- Inn: An interface between the R-IPRG in this network domain and the R-IPRG of other network domains. This interface is used to share useful policy rules among different network domains. + +# **8 Implementation methods for intelligent management and maintenance of PIB** + +## **8.1 Overview of feasible implementation methods** + +As described in Figure 7-1, L-IPRG and R-IPRG can manage and maintain DPI-PIB by using intelligent algorithms. + +The steps of the feasible implementation methods are as follows: + +- (1) When a packet passes through the device, the DPI feature mining function (DPI-FMF) senses the traffic feature and feeds back to the L-IPRG. +- (2) The L-IPRG sends this mining traffic feature information to the R-IPRG and saves it to the local database if required. + +- (3) The L-IPRG generates new policy items based on some AI algorithms and according to this mining traffic feature information, current PIB, policy management configuration, etc. Then the L-IPRG feeds these policies back to L-PDF+. +- (4) L-PDF+ compares these received policy items with the existing PIB and, if there are not similar policy items in PIB, L-PDF+ updates PIB by adding these new policy items. +- (5) The DPI-PIB saves the policy items and notifies the L-IPRG, the DPI SCF and the DPI Anf. +- (6) R-IPRG receives the mining traffic information in step (2) and the external traffic information, generates new policy items based on some AI algorithms, and sends these policy items to L-IPRG and R-PDF+. Then R-PDF+ sends them L-PDF+, and these generated policy items are updated the same as steps (4) and (5). +- (7) The R-IPRG sends this mining traffic information and PIB to the NTS, and the NTS generates the virtual traffic information and evaluates the policy information. + +In the whole process, the L-IPRG generates policies mainly based on local device mining traffic and PIB, but the R-IPRG generates policies based on all traffic information in the network. L-IPRG and R-IPRG predict the future traffic requirements based on the dynamic traffic and network information, and output PIB. There are many methods for the dynamic PIB algorithms based on traffic perception, for example, generating adversarial network algorithms, evolutionary algorithms and clustering algorithms. + +## 8.2 Implementation method based on generative adversarial network + +Generative adversarial network (GAN) is a class of ML model. It establishes a generating network and a discriminating network with the idea of game. Through the adversarial training of the generating network and the discriminating network, GAN can generate applicable policy rules for PIB. + +So the PIB generation model can be constructed based on GANs. When the DPI system realizes automatic and intelligent management and maintenance of PIB based on GAN, a DPI entity based on GAN (it is also based on functional architecture described in clause 7) is different from the traditional DPI entity and has the following feature: a functional component local DPI GAN (in other words, GAN-based L-IPRG, represented by DPI-L-GAN) is deployed in the DPI entity. Another functional component DPI feature mining function (DPI-FMF) is deployed in the DPI engine, and DPI-FMF follows DPI-Anf. In addition, two functional components, remote DPI GAN (in other words GAN-based R-IPRG, represented by DPI-R-GAN), and NTS, are deployed in DPI control plane. Figure 8-1 describes the new functional components deployed in the DPI system. + +DPI-L-GAN, DPI-R-GAN and NTS coordinate to realize the automatic management and maintenance of PIB, as follows: + +First, the rules in the current PIB are divided into two sets – A and B. + +Secondly, generative network Gl of DPI-L-GAN accepts A and features F (learned from DPI-FMF) as input, while generative network Ge of DPI-R-GAN accepts A, features F and simulated traffic S (generated by NTS) as input. + +Thirdly, Gl of DPI-L-GAN and Ge of DPI-R-GAN generate new policy rules Rn, based on input. + +Fourthly, Rn and rule set B are inputted into discriminative network Dl of DPI-L-GAN and discriminative network De of DPI-R-GAN, in order to confirm whether Rn is logically effective. + +Fifthly, based on NTS, Rn is evaluated and tested in order to confirm whether Rn is functionally effective. + +Finally, Rn that is logically and functionally effective is added to PIB while PIB is checked and updated. + +![Figure 8-1: DPI system architecture diagram showing Control plane, Management plane, and Data plane components.](fa859e4e468bfb2710a94527f2c504af_img.jpg) + +The diagram illustrates the architecture of a DPI system deployed with GAN and NTS, organized into three main planes: Control plane, Management plane, and Data plane. + +- Control plane:** Contains the **Network traffic simulator (NTS)** and the **Remote GAN (GAN based R-IPRG)**. The NTS sends traffic to the Remote GAN, which then forwards it to the DPI entity. +- Management plane:** Contains the **R-PDF+** and the **General policy management** block. The R-PDF+ interacts with the DPI entity via a **Policy management interface**. The General policy management block includes **DPI policy management** and **DPI session management**. It receives **DPI policy rules** from the DPI entity and sends **Report information** back. +- Data plane:** Contains the **DPI entity**, which is further divided into: + - DPI PEF:** Includes the **Local GAN (GAN based L-IPRG) or agent for remote GAN** and the **DPI-PIB**. The Local GAN receives traffic from the Remote GAN and interacts with the DPI-PIB via **Rule operation** and **Rule** exchanges. The DPI-PIB sends **Rule and action** information to the DPI-FMF. + - DPI-FMF:** Receives **Flow information** from the DPI-PIB and sends it to the DPI-AcEF. + - DPI-AcEF:** Receives flow information from the DPI-FMF and sends it to the **Routing and forwarding** block. + - Packet forwarding:** Includes the **FIB** and the **Routing and forwarding** block. The Routing and forwarding block receives traffic from the DPI-AcEF and sends it to the **Traffic egress**. + +Legend: **Control information** is indicated by a dashed line with a square head. + +Y.2776(24) + +Figure 8-1: DPI system architecture diagram showing Control plane, Management plane, and Data plane components. + +**Figure 8-1 – DPI system deployed with GAN and NTS** + +The workflow of DPI-L-GAN and DPI-R-GAN is illustrated in Figure 8-2. It is noted that DPI-L-GAN and DPI-R-GAN have a similar workflow and their output is different. + +![Figure 8-2: Workflow of DPI-L-GAN and DPI-R-GAN. The diagram illustrates a Generative Adversarial Network (GAN) architecture for policy rule generation. It starts with 'Network traffic feature' (represented by triangles) and 'Part A of the current PIB' (represented by circles) as inputs to the 'Generative network G'. 'Generative network G' produces a 'Generated policy rule' (represented by rectangles). This rule is then fed into the 'Discriminative network D' along with 'Part B of the current PIB' (represented by circles). 'Discriminative network D' outputs a 'Discriminative result (Probability of the rule set up manually)'. A reference 'Y.2776(24)' is noted at the bottom right.](8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg) + +Figure 8-2: Workflow of DPI-L-GAN and DPI-R-GAN. The diagram illustrates a Generative Adversarial Network (GAN) architecture for policy rule generation. It starts with 'Network traffic feature' (represented by triangles) and 'Part A of the current PIB' (represented by circles) as inputs to the 'Generative network G'. 'Generative network G' produces a 'Generated policy rule' (represented by rectangles). This rule is then fed into the 'Discriminative network D' along with 'Part B of the current PIB' (represented by circles). 'Discriminative network D' outputs a 'Discriminative result (Probability of the rule set up manually)'. A reference 'Y.2776(24)' is noted at the bottom right. + +**Figure 8-2 – Workflow of DPI-L-GAN and DPI-R-GAN** + +When the DPI system has deployed the aforementioned functional components related to GAN, the realized DPI method is also different from the traditional DPI method and it has the following attributions or steps: + +When network traffic enters the DPI node, the traffic is scanned and analysed based on the present policy rule base. If there is a certain rule to match the traffic, actions in the rule are executed. If there is not any matched rule, the feature mining action is executed and the mining result is sent to DPI-L-GAN and the enhanced DPI-R-GAN so that the two GANs generate new rules $R_n$ . When the new rule $R_n$ is generated and confirmed, it is analysed and optimized with the rules in PIB, and the network traffic is sent back to the scanning stage. + +It is necessary that new rule $R_n$ is analysed and optimized with the rules in PIB, in case that $R_n$ is contradicted or partly duplicated with the existing rules. + +## 8.3 Implementation method based on evolving algorithm + +Evolving algorithm (EA) is a powerful tool for solving complex optimization problems. EA employs iterative search to find the optimal solution. The population (solutions) is first randomly initialized, and the individuals in the population are updated with some rules to achieve population evolution. The individuals in the population gradually reach the optimal solution in an iterative process. + +EA entity can be deployed in either L-IPRG or R-IPRG. The DPI-FMF monitors the network traffic and sends it to the L-IPRG and the R-IPRG, as the EA entity input. a Then the EA generates a PIB that meets all the requirements of that traffic. + +The PIB generation method based on EA is shown in Figure 8-3. The population is randomly initialized in the feasible PIB, and a random entry is selected as the initial PIB item individual. Calculate the population that meets the forwarding rules of all streams. The number of PIB item individuals in this population should be greater than a minimum. Then, some PIB item individuals that are selected from the current population are crossed and varied to obtain new individuals. The new PIB item individuals in this population are then evaluated as before until the current PIB item individual meets the requirements or the termination conditions are met. Finally, the minimum number of PIB items are output as the optimal PIB. + +![Flowchart of the PIB generation method based on EA. The process starts with 'Begin', followed by 'The population is randomly initialized in the feasible PIB and a random entry is selected as the initial PIB item individual'. Then, 'Calculate population to meet the forwarding rules of all streams, and the number of PIB item individuals is minimum'. A decision diamond asks 'Whether to meet the requirements'. If 'Yes', it goes to 'Output results' and then 'End'. If 'No', it goes to 'Some PIB item individuals are selected from the current population', then 'Cross and vary the selected PIB items to obtain new individuals', and loops back to the calculation step.](76b0cd79baaedd942af4dc42f2e764b8_img.jpg) + +``` + +graph TD + Begin([Begin]) --> Init[The population is randomly initialized in the feasible PIB and a random entry is selected as the initial PIB item individual] + Init --> Calc[Calculate population to meet the forwarding rules of all streams, and the number of PIB item individuals is minimum] + Calc --> Dec{Whether to meet the requirements} + Dec -- Yes --> Output[Output results] + Output --> End([End]) + Dec -- No --> Sel[Some PIB item individuals are selected from the current population] + Sel --> Cross[Cross and vary the selected PIB items to obtain new individuals] + Cross --> Calc + +``` + +Y.2776(24) + +Flowchart of the PIB generation method based on EA. The process starts with 'Begin', followed by 'The population is randomly initialized in the feasible PIB and a random entry is selected as the initial PIB item individual'. Then, 'Calculate population to meet the forwarding rules of all streams, and the number of PIB item individuals is minimum'. A decision diamond asks 'Whether to meet the requirements'. If 'Yes', it goes to 'Output results' and then 'End'. If 'No', it goes to 'Some PIB item individuals are selected from the current population', then 'Cross and vary the selected PIB items to obtain new individuals', and loops back to the calculation step. + +**Figure 8-3 – PIB generation method based on EA** + +Evolving algorithms include a variety of improved algorithms, such as evolutionary programming, evolutionary strategies, genetic algorithms, differential evolution, particle swarm optimization, artificial bee colony, ant colony algorithm and whale algorithm. + +## 8.4 Implementation method based on cluster algorithm + +Cluster algorithm (CA) is an unsupervised ML. The data is divided into several clusters by dynamically measuring the similarity between the data instances. This makes the similarity between the data instances within the same cluster as high as possible, and the similarity between the data instances belonging to the different clusters as low as possible. + +CA entity can be deployed in either L-IPRG or R-IPRG. The DPI-FMF monitors the network traffic and sends it to the L-IPRG and the R-IPRG, as the CA entity input. The CA divides the data into appropriate clustering and generates PIB based on the clustering features. The steps of the PIB generation method based on CA are as follows: + +- 1) Determine the number of target clusters $K$ , the scale, and the number of iterations limited. +- 2) $K$ flows are randomly selected in the flow set as the initial centre point. +- 3) Calculate the distance from each flow to all central points in the flow set. Each flow is divided into the closest cluster. Then form the cluster allocation matrix. +- 4) Calculate the mean distance from each point to the centre point in the cluster and set the mean distance point as the new centre. + +- 5) Repeat the steps (3) and (4) until the centre no longer moves or the repeating number reaches the number of iterations limited. +- 6) Output $K$ centres and $K$ clusters, and generate dynamic PIB by them. + +The PIB generation method based on CA is shown in Figure 8-4. + +![Flowchart of the PIB generating method based on CA. The process starts with 'Begin', followed by 'Determine the number of target clusters K, the scale N, and the number of iterations limited.' Then, 'K flows are randomly selected as the initial centre point.' This is followed by a loop: 'Each flow is divided into the closest cluster. And then form the cluster allocation matrix.' -> 'Set the mean distance point as the new centre.' -> Decision: 'Whether the centre no change or reaches the number of iterations limited?'. If 'No', it loops back to the clustering step. If 'Yes', it proceeds to 'Output results' and then 'End'.](2b3a967f6ce4f23649be995a353e39f8_img.jpg) + +``` + +graph TD + Begin([Begin]) --> Determine[Determine the number of target clusters K, the scale N, and the number of iterations limited.] + Determine --> Select[K flows are randomly selected as the initial centre point.] + Select --> Cluster[Each flow is divided into the closest cluster. And then form the cluster allocation matrix.] + Cluster --> SetCentre[Set the mean distance point as the new centre.] + SetCentre --> Decision{Whether the centre no change or reaches the number of iterations limited?} + Decision -- No --> Cluster + Decision -- Yes --> Output[Output results] + Output --> End([End]) + +``` + +Y.2776(24) + +Flowchart of the PIB generating method based on CA. The process starts with 'Begin', followed by 'Determine the number of target clusters K, the scale N, and the number of iterations limited.' Then, 'K flows are randomly selected as the initial centre point.' This is followed by a loop: 'Each flow is divided into the closest cluster. And then form the cluster allocation matrix.' -> 'Set the mean distance point as the new centre.' -> Decision: 'Whether the centre no change or reaches the number of iterations limited?'. If 'No', it loops back to the clustering step. If 'Yes', it proceeds to 'Output results' and then 'End'. + +**Figure 8-4 – PIB generating method based on CA** + +The clustering algorithm is simple. Different cluster algorithms can be selected according to the application, the type of transmission, and the different purposes. These cluster algorithms include partition methods, hierarchical methods, density-based methods, grid-based methods and model-based methods. + +## 8.5 Implementation method based on other methods + +PIB generation is to identify the forwarding policy based on the traffic. Many other algorithms based on ML can calculate PIB. As shown in Figure 8-5, there are some AI methods that can calculate PIB too, and these AI method entities are deployed in either L-IPRG or R-IPRG. + +![Figure 8-5: A hierarchical diagram showing the relationship between Artificial Intelligence, Machine Learning, and various AI/ML algorithms. Artificial intelligence is the outermost oval, containing Knowledge reasoning and Machine learning. Machine learning is an inner oval containing Supervised learning, Unsupervised learning, Deep learning, and Reinforcement learning. Below these are 15 vertical rectangles representing specific algorithms: K-neighbour, Bayes classifier, Vector machine, Decision tree, Multi-layer perceptron, Boltzmann machine, Autoencoder, Convolutional neural network, Recurrent neural network, Generative adversarial network, Q-learning, Fuzzy Q-learning, K-mean cluster, Game theory, Self-organization network, and Anomaly detection. Dashed lines connect the top-level categories to the specific algorithms.](b6671cfafda3820aafe9a24fa7a4d8c7_img.jpg) + +Y.2776(24) + +Figure 8-5: A hierarchical diagram showing the relationship between Artificial Intelligence, Machine Learning, and various AI/ML algorithms. Artificial intelligence is the outermost oval, containing Knowledge reasoning and Machine learning. Machine learning is an inner oval containing Supervised learning, Unsupervised learning, Deep learning, and Reinforcement learning. Below these are 15 vertical rectangles representing specific algorithms: K-neighbour, Bayes classifier, Vector machine, Decision tree, Multi-layer perceptron, Boltzmann machine, Autoencoder, Convolutional neural network, Recurrent neural network, Generative adversarial network, Q-learning, Fuzzy Q-learning, K-mean cluster, Game theory, Self-organization network, and Anomaly detection. Dashed lines connect the top-level categories to the specific algorithms. + +**Figure 8-5 – The dynamic PIB generation method based on other AI/machine learning algorithms** + +The principle of calculating the PIB methods by AI algorithms is a feedback closed-loop system based on big data analysis for PIB applications, as shown in Figure 8-6. (1) Data collection and processing. The DPI-FMF monitors the network traffic and sends it to the L-IPRG and the R-IPRG, as the algorithm input. (2) Big data analysis includes cluster, cause analysis, and other algorithms. (3) The solution can be a scenario PIB generation method based on an optimization AI algorithm. + +![Figure 8-6: A flowchart of a feedback closed-loop system. It consists of three main boxes: 'Data collection and processing', 'Big data analysis', and 'Dynamic PIB methods'. Arrows show a linear flow from left to right: Data collection and processing to Big data analysis, and Big data analysis to Dynamic PIB methods. A feedback arrow points from the bottom of the 'Dynamic PIB methods' box back to the bottom of the 'Data collection and processing' box.](81a4cbf0b3c4cbc065efdf8f800dadde_img.jpg) + +Y.2776(24) + +Figure 8-6: A flowchart of a feedback closed-loop system. It consists of three main boxes: 'Data collection and processing', 'Big data analysis', and 'Dynamic PIB methods'. Arrows show a linear flow from left to right: Data collection and processing to Big data analysis, and Big data analysis to Dynamic PIB methods. A feedback arrow points from the bottom of the 'Dynamic PIB methods' box back to the bottom of the 'Data collection and processing' box. + +**Figure 8-6 – Feedback closed-loop system based on big data analysis** + +AI method implements PIB through the above closed-loop system. There are many ML algorithms for big data analysis, such as transfer learning, incremental learning, federated learning, or shared learning. + +# 9 Functional requirements for intelligent management and maintenance of PIB + +## 9.1 Functional requirements for DPI entity + +As the basic component to realize the DPI functions, a DPI entity is critical to intelligent management and maintenance of PIB. In addition, a DPI entity comprises the following three independent but correlated parts: + +- DPI engine (including DPI-SCF, DPI-AnF, DPI FMF and DPI-AcEF). + +- DPI-PIB. +- L-PDF+. + +The functional requirements for the DPI engine and L-PDF+ will be described in the following sections. Then, this section focuses on functional requirements related to the DPI entity itself and PIB. + +The following functional requirements should be realized by a DPI entity: + +- The DPI entity is required to support the capability to send and receive information from the external management or control entities. +- The DPI entity is required to support negotiation data structure for information exchanged between the DPI entity and external management or control entities. +- The DPI entity is recommended to support a data encryption mechanism for information exchanged between the DPI entity and external management or control entities. +- The DPI entity is recommended to support protocol negotiation for information exchanged between the DPI entity and external management or control entities. +- The DPI entity is recommended to support policy rule evaluation when there are some contradictions among policy rules from different management or control entities. +- The DPI-PIB is recommended to set up a field that is used to describe the priority of the policy rule. + +NOTE – When there are some contradictions among policy rules from different management or control entities, the priority field is used to discriminate between them. + +- The DPI-PIB is recommended to merge correlated policy rules if the new policy rule can cover the policy rules that have been merged. +- The DPI-PIB is recommended to set up a check field in order that the illegal modification of the DPI-PIB can be found and avoided. + +## 9.2 Functional requirements for R-PDF+ + +It can be learned from Figure 7-1 that R-PDF+ is outside of the DPI entity and there are possibly one or more R-PDF+ co-existing in the DPI realization. In addition, an R-PDF+ has a connection with the R-IPRG and L-PDF+. + +The design for R-PDF+ should meet the following functional requirements: + +- The R-PDF+ is required to support the capability to send and receive information from the functional component R-IPRG. +- The R-PDF+ is required to support the capability to send and receive information from the functional component L-PDF+. +- The R-PDF+ is recommended to support the capability to negotiate data structure for information exchanged between R-PDF+ and the functional component R-IPRG. +- The R-PDF+ is recommended to support the capability to negotiate protocol for information exchanged between R-PDF+ and the functional component R-IPRG. +- The R-PDF+ is recommended to support the capability to negotiate data structure for information exchanged between R-PDF+ and the functional component L-PDF+. +- The R-PDF+ is recommended to support the capability to negotiate protocol for information exchanged between R-PDF+ and the functional component L-PDF+. +- The R-PDF+ is recommended to support the capability to encrypt information exchanged between R-PDF+ and the functional component R-IPRG. +- The R-PDF+ is recommended to support the capability to exchange keys between R-PDF+ and the functional component R-IPRG. + +- The R-PDF+ is recommended to support the capability to encrypt information exchanged between R-PDF+ and the functional component L-PDF+. +- The R-PDF+ is recommended to support the capability to exchange keys between R-PDF+ and the functional component L-PDF+. + +## 9.3 Functional requirements for L-PDF+ + +Figure 7-1 illustrates that L-PDF+ is in the DPI entity and an L-PDF+ has a connection with the L-IPRG and R-PDF+. + +The design for L-PDF+ should meet the following functional requirements: + +- The L-PDF+ is required to support the capability to send and receive information from the functional component L-IPRG. +- The L-PDF+ is required to support the capability to send and receive information from the functional component R-PDF+. +- The L-PDF+ is recommended to support the capability to negotiate data structure for information exchanged between L-PDF+ and the functional component L-IPRG. +- The L-PDF+ is recommended to support the capability to negotiate data structure for information exchanged between L-PDF+ and the functional component R-PDF+. +- The L-PDF+ is recommended to support the capability to negotiate protocol for information exchanged between L-PDF+ and the functional component R-PDF+. +- The L-PDF+ is recommended to support the capability to encrypt information exchanged between L-PDF+ and the functional component R-PDF+. +- The L-PDF+ is recommended to support the capability to exchange keys between L-PDF+ and the functional component R-PDF+. + +## 9.4 Functional requirements for the DPI-Scf component + +DPI-Scf is a sub-component of the DPI-engine. The following requirements should be supported by DPI-Scf: + +- The DPI-Scf is required to support the capability to scan the traffic according to policy rules. +- The DPI-Scf is recommended to support the capability to scan the traffic according to feature sets generated by the functional component DPI-FMF. +- The DPI-Scf is recommended to support the capability to scan the traffic based on the priorities of the policy rules or mined features. + +## 9.5 Functional requirements for the DPI-Anf component + +DPI-Anf is also a sub-component of the DPI-engine. The following requirements should be supported by DPI-Anf: + +- The DPI-Anf is required to support the capability to analyse the traffic according to policy rules. +- The DPI-Anf is recommended to support the capability to analyse the traffic according to feature sets generated by the functional component DPI-FMF. +- The DPI-Anf is recommended to support the capability to analyse the traffic based on the priorities of the policy rules or mined features. + +## 9.6 Functional requirements for internal interfaces + +There are following two internal interfaces that are necessary to implement intelligent management and maintenance of PIB: + +- iLL: the interface between functional component L-IPRG and L-PDF+. +- iLF: the interface between functional component L-IPRG and sub-engine DPI-FMF. + +The following requirements should be supported by the aforementioned interfaces: + +- The interface iLL is required to support information exchange between L-IPRG and L-PDF+. +- The interface iLL is recommended to support multiple transport protocols such as TCP and UDP. +- The interface iLL is recommended to support negotiating transport protocols dynamically. +- The interface iLF is required to support receiving data from sub-engine DPI-FMF. +- The interface iLF is recommended to support flow control functions while receiving data. + +## 9.7 Functional requirements for external interfaces + +There are following four external interfaces that are necessary to implement intelligent management and maintenance of PIB: + +- iRE: the interface between functional component R-IPRG and NTS. +- iRO: the interface between functional component R-IPRG and outside of the network. +- iRR: the interface between functional component R-IPRG and R-PDF+. +- iRL: the interface between functional component R-IPRG and L-IPRG. + +The following requirements should be supported by the aforementioned interfaces: + +- The interface iRE is required to support information exchange between R-IPRG and NTS. +- The interface iRO is required to support information exchange between R-IPRG and the other networks or systems. +- The interface iRO is recommended to support secure transport protocols such as TLS and QUIC. +- The interface iRO is recommended to support negotiating transport protocol dynamically. +- The interface iRR is required to support information exchange between R-IPRG and R-PDF+. +- The interface iRL is required to support information exchange between R-IPRG and L-IPRG. +- The interface iRL is recommended to support secure transport protocols such as TLS and QUIC. +- The interface iRL is recommended to support negotiating transport protocol dynamically. + +# 10 Performance aspects for intelligent management and maintenance of PIB + +## 10.1 Process time for intelligent management and maintenance of PIB + +It is very important for PIB to be updated as soon as possible. For example (see Figure 10-1), if it takes too much time to write policy rule A into PIB, policy rule A cannot take effect until it can be read from PIB. Within the writing time of policy rule A, a lot of network traffic would escape the analysis based on the policy rule. + +A similar circumstance is that policy rule A is removed from PIB. When the time to remove policy rule A is too long, policy rule A will take effect and have an influence on the network traffic within the time. + +![Figure 10-1: Influence for a policy rule to be written or removed from PIB. The diagram shows a flow of network traffic through three DPI stages: DPI-SCF, DPI-Anf, and DPI-AcEF. Above these stages is a box containing a list of policy rules: Policy rule 1, Policy rule 2, ..., Policy rule n. Dashed arrows point from each of these three DPI stages to the 'Policy rule n' box. A dashed arrow also points from the 'Policy rule n' box to 'Policy rule A' outside the main box. Network traffic enters from the left and exits to the right.](c5452f95f3b28f1bfe29e84fbc2e1267_img.jpg) + +Figure 10-1: Influence for a policy rule to be written or removed from PIB. The diagram shows a flow of network traffic through three DPI stages: DPI-SCF, DPI-Anf, and DPI-AcEF. Above these stages is a box containing a list of policy rules: Policy rule 1, Policy rule 2, ..., Policy rule n. Dashed arrows point from each of these three DPI stages to the 'Policy rule n' box. A dashed arrow also points from the 'Policy rule n' box to 'Policy rule A' outside the main box. Network traffic enters from the left and exits to the right. + +**Figure 10-1 – Influence for a policy rule to be written or removed from PIB** + +Therefore, the process time for the intelligent management and maintenance of PIB should have a threshold. The process time should meet the following performance requirement: + +- It is recommended that the process time for each policy rule is less than 50 ms. + +## 10.2 Storage usage for intelligent management and maintenance of PIB + +Storage usage is also an important factor of PIB. On the one hand, storage usage cannot be too high. Under such circumstances, upcoming valued policy rules are possibly not able to be written into PIB. On the other hand, it is also not a good situation that the storage usage is too low, because it means the waste of precious storage resources under such a circumstance. + +A good design for intelligent management and maintenance of PIB is to keep the storage usage at an appropriate level. In other words, storage usage should have a bottom threshold and a top threshold. + +The storage usage should meet the following performance requirements: + +- It is recommended to use average storage usage and the average storage usage should be greater than 70%. +- It is recommended to use peak storage usage and the peak storage usage should be less than 95%. + +## 10.3 Process correct rate for intelligent management and maintenance of PIB + +Process correct rate is the correction rate that policy rules are written into or removed from PIB. When a certain rule is written into PIB, if the rule takes effect, the writing operation is correct; however, if the rule does not take effect, the writing operation is incorrect. When a certain rule is removed from PIB, if the rule can still take effect, the removing operation is incorrect; however, if the rule is really useless, the removing operation is correct. + +Process correct rate can be represented by the following formula: + +$$Pc = (Wc + Rc) / (W + R)$$ + +Pc represents the process's correct rate. W and R represent the total times of writing operation and removing operation, respectively. Wc and Rc represent the total times of correct writing operation and correct removing operation. + +The process time Pc should meet the following performance requirement: + +- It is recommended that Pc is greater than 99%. + +## 10.4 Network traffic awareness correct rate + +The network traffic awareness correct rate is the correction rate that the DPI entity identifies the traffic based on the policy rules of PIB. [ITU-T Y.2771] and [ITU-T Y.2773] have specified three performance indexes to describe the network traffic awareness correct rate. + +$\varepsilon\text{f-p}$ : False-positive error rate + +$\varepsilon\text{f-n}$ : False-negative error rate + +$\varepsilon\text{DPI}$ : Total error rate + +When managing PIB by using intelligent methods, it is possible that the values of $\varepsilon\text{f-p}$ , $\varepsilon\text{f-n}$ and $\varepsilon\text{DPI}$ ascend. However, the three error rates should not exceed a certain threshold too. + +The network traffic awareness rate should meet the following performance requirement: + +It is recommended that the following inequality be obeyed by intelligent management and maintenance of PIB: + +$$\varepsilon\text{f-p(I)} \leq 110\% \times \varepsilon\text{f-p}$$ + +$$\varepsilon\text{f-n(I)} \leq 110\% \times \varepsilon\text{f-n}$$ + +$$\varepsilon\text{DPI(I)} \leq 110\% \times \varepsilon\text{DPI}$$ + +$\varepsilon\text{f-p(I)}$ , $\varepsilon\text{f-n(I)}$ and $\varepsilon\text{DPI(I)}$ represent the value of $\varepsilon\text{f-p}$ , $\varepsilon\text{f-n}$ and $\varepsilon\text{DPI}$ , respectively, while intelligent management of PIB is used. + +## 10.5 Network traffic awareness volume + +Network traffic awareness volume is measured by "Packet processing rate" (see [ITU-T Y.2771]). "Packet processing rate" is represented by $\phi\text{P,In}$ . + +If PIB is managed and maintained by using the intelligent method, it is possible that the value of $\phi\text{P,In}$ descends. However, the processing rate should not be lower than a certain threshold too. + +About network traffic awareness volume, the performance requirement is as follows: + +It is recommended that the following inequality be obeyed by intelligent management and maintenance of PIB: + +$$\phi\text{P,In (I)} \geq 95\% \times \phi\text{P,In}$$ + +$\phi\text{P,In (I)}$ represents the value of $\phi\text{P,In}$ while intelligent management of PIB is used. + +# 11 Control plane considerations + +## 11.1 DPI-PIB control plane requirements + +DPI-PIB can realize the collaboration of multiple DPI-PIB supporting nodes in the network to complete the further function of deep packet detection together. The general requirements of the PIB control plane (such as R-PDF+) are being described as follows: + +- PIB control plane is required to support the capability to notify static and dynamic PIB information. +- PIB control plane is required to support the capability to notify PIB processing capabilities of DPI node. +- PIB control plane is recommended to support the capability of multiple DPI rules aggregation. + +NOTE 1 – DPI rules aggregation means two or more correlated DPI policy rules collaborate to take effect. + +- PIB control plane is recommended to support the capability to handle the expected number of PIB rules. + +NOTE 2 – The expected number of PIB rules depends on application scenarios. + +- PIB control plane is recommended to support the capability to provide DPI policy information of all DPI nodes. + +These requirements can be satisfied by using distributed control mechanisms, centralized network management configuration mechanisms, or a hybrid combination of both. + +## **11.2 DPI-PIB control plane considerations** + +### **11.2.1 PIB rule generation** + +The process of distributed PIB rule generation includes four functions that are described as follows: + +- DPI-PIB resource collection: Available DPI-PIB resources are tracked through the control plane and distributed to other nodes. +- DPI services path determination: When providing or requesting a DPI service that requires multiple DPI nodes to work together, one or more paths that the requirements need are selected, and the DPI-PIB resources are validated and documented. +- DPI-PIB resource allocation and data plane coordination: DPI-PIB resources are allocated along the path, depending on the DPI method used by each node. +- Allocated DPI-PIB resource records and updates: Depending on the adopted DPI method, the allocated DPI-PIB resources are updated and distributed to the DPI entities. + +NOTE – DPI-PIB resource allocation mainly refers to PIB policy items for DPI node. + +### **11.2.2 PIB synchronize mechanism** + +The DPI-PIB in the control plane is required to be synchronized with DPI-PIB of the other DPI nodes. The synchronization process can be initiated by the control plane or the DPI node. The main process of the control plane is as follows: + +- DPI node sends PIB information message to all other DPI nodes when its PIB rules are changed. Normally, the control plane should receive messages of policy rules from other DPI nodes and take the received DPI-PIB information as the input for intelligent computing. +- To avoid too many messages, a primary DPI node can be elected to periodically report the PIB information. If the control plane detects that the PIB information reported is inconsistent with its own PIB information, the control plane updates these different policy rules. + +### **11.2.3 PIB control information summary** + +The following summarizes the set of information that is needed to identify DPI-PIB. + +The specific information needed to process each DPI service depends on the type of network and the functionality provided by the DPI node. + +This information required on the DPI nodes is described as follows: + +- DPI rules information: DPI rules information can be represented by the data and mask length in the data and mask representation method, or by hierarchical regular expressions in the regular expression representation method, etc. It is not required by the relay node. +- DPI policy corresponding action information: Processing actions for matching data flows, such as forwarding after copying, counting, dropping after counting, and adding or removing tag information. +- Policy rules generation algorithm: Contain information about the policy rule generation algorithm, and the parameters required for the algorithm, such as the number of iterations and threshold values. + +- DPI features mining: Configure common parameters such as the DPI feature mining mechanism. +- Local rule generation and remote rule generation: Includes local generation of policy rules; remote generation of policy rules; and generation of policy rules through collaboration of local and remote. + +# **12 Management and application considerations** + +## **12.1 Overview requirements of management aspect** + +- Intelligent management for PIB of DPI is recommended to support commonly used management protocols such as SNMP and NETCONF/SSH/TELNET. +- Intelligent management for PIB of DPI is recommended to support the YANG model. +- Intelligent management for PIB of DPI is recommended to support other management models such as the management information base (MIB) model. + +## **12.2 Requirements of management and configuration** + +- Intelligent management for PIB of DPI is required to support storing and importing configuration information. +- Intelligent management for PIB of DPI is recommended to support management interfaces such as NETCONF and CLI. +- Intelligent management for PIB of DPI is recommended to support the priority threshold configuration for writing log information. + +NOTE – Only the log information that has a higher priority than the priority threshold can be written into the log file. + +- Intelligent management for PIB of DPI is recommended to support online upgrading of software and firmware. +- Intelligent management for PIB of DPI is required to support the capabilities to restore the default configuration +- Intelligent management for PIB of DPI is required to support the capabilities to scan and review the PIB information. +- Intelligent management for PIB of DPI is recommended to support the capabilities to predict the trouble of the system. +- Intelligent management for PIB of DPI is recommended to support the capabilities of self-recovering. + +## **12.3 Requirements of log management** + +- Intelligent management for PIB of DPI is recommended to support the capabilities to open and close the log management function. +- Intelligent management for PIB of DPI is recommended to support the capabilities to manage the log of configuration and operation. +- Intelligent management for PIB of DPI is recommended to support the capabilities to store log information of a certain priority. +- Intelligent management for PIB of DPI is required to support the capabilities to look up the log information based on time, type and priority. +- Intelligent management for PIB of DPI is required to support the capabilities to report log information to the controller. + +- Intelligent management for PIB of DPI is required to support the capabilities to report alarm log information to the network management system. + +## **12.4 Requirements of application** + +- Intelligent management for PIB of DPI is recommended to support the capabilities to deploy the functions based on cloud computing. +- Intelligent management for PIB of DPI is recommended to support the capabilities to deploy the functions based on distribution mode. +- Intelligent management for PIB of DPI is recommended to support the capabilities to update the DPI system smoothly. +- Intelligent management for PIB of DPI is recommended to support the capabilities to deploy the functions based on load balance. +- Intelligent management for PIB of DPI is required to support the capabilities to visualize the deployment information. + +# **13 Security considerations** + +Regulation, privacy and security application aspects of DPI are outside the scope of this Recommendation. Vendors, operators, and service providers are required to take into account national regulatory and policy requirements when implementing this Recommendation. + +According to [ITU-Y.2770], the DPI-FE and the information pertaining to DPI operations should be under protection against threats. The mechanisms specified in [ITU-T Y.2704] address the security requirements of [ITU-T Y.2770]. + +# Bibliography + +- [b-ITU-T Y.2121] Recommendation ITU-T Y.2121 (2008), *Requirements for the support of flow-state-aware transport technology in NGN*. +- [b-IETF RFC 3198] IETF RFC 3198 (2001), *Terminology for Policy-Based Management*. + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/Y/T-REC-Y.2812-201207-I_PDF-E/11edb7fcedf09ac6a817f8d7b8c61eec_img.jpg b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/11edb7fcedf09ac6a817f8d7b8c61eec_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..6473e20cee62ddc206b4ef1ad7be4c10a13385f4 --- /dev/null +++ b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/11edb7fcedf09ac6a817f8d7b8c61eec_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:8f72a873282aca4373f91b0df95ced50acf04e7496134f7d6a6dfa17a5798ac2 +size 135901 diff --git a/marked/Y/T-REC-Y.2812-201207-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..26fc27df271c204031f316f3fc7f2fbaf6bae950 --- /dev/null +++ b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/33ed1f9b27c7c21c797aa928b0f06851_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:15ba3fe47726b45620c43d005efa91da55609fa70211b85c779d0ead29e3ff93 +size 45075 diff --git a/marked/Y/T-REC-Y.2812-201207-I_PDF-E/365b54f616aff249b4e6c0edafdcb9b3_img.jpg b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/365b54f616aff249b4e6c0edafdcb9b3_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..c1efa41053e3dec73c9fcb9967a79047947e3795 --- /dev/null +++ b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/365b54f616aff249b4e6c0edafdcb9b3_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:ab7663ccf96e5bbf384f072be23b6cb21ea4d04b56aefbed24960fb6b1c8c4c6 +size 123998 diff --git a/marked/Y/T-REC-Y.2812-201207-I_PDF-E/3cc095fb84e92690c9d49d3e17c0f1dc_img.jpg b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/3cc095fb84e92690c9d49d3e17c0f1dc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..5f385e75650cf029d4d7beda66e458789a263a46 --- /dev/null +++ b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/3cc095fb84e92690c9d49d3e17c0f1dc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:b3e08036168b17e571b99b911ab90296dc2e243533ba07cdbc6d27e94edddcc8 +size 30689 diff --git a/marked/Y/T-REC-Y.2812-201207-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..45af3fc26ce5594a89b2d4278735d959f3fe415d --- /dev/null +++ b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:acae709346f1be3b8ea84bc390d8d32e035a5905e8242091696802cfc4d4361a +size 46884 diff --git a/marked/Y/T-REC-Y.2812-201207-I_PDF-E/48a4d999034fb203698ddc187c259679_img.jpg b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/48a4d999034fb203698ddc187c259679_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..cdc04727bc33a7239d422dd0c59fb54af4132417 --- /dev/null +++ b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/48a4d999034fb203698ddc187c259679_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:a6dff308b6b934357f38199a65cd48eb302f027ff4aa8054662e3217baadb31c +size 80136 diff --git a/marked/Y/T-REC-Y.2812-201207-I_PDF-E/5445597cceefaca1ac89e710fe339325_img.jpg b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/5445597cceefaca1ac89e710fe339325_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..c5c748dc0e6514fd42c6e13c629db9b38e9d58e6 --- /dev/null +++ b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/5445597cceefaca1ac89e710fe339325_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:7878876074bd8d5db2b046078831fc1cecbbbf46186247f228b957087e1b9098 +size 126798 diff --git a/marked/Y/T-REC-Y.2812-201207-I_PDF-E/692541e65db4dc852988ce77ebb60ce5_img.jpg b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/692541e65db4dc852988ce77ebb60ce5_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..fb5b8617658287337c86d408b4eb7969f1b07c4b --- /dev/null +++ b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/692541e65db4dc852988ce77ebb60ce5_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:1e19ed88a54bd6900050dc9204b8326c6315287902162ecc6629a2791716f144 +size 101414 diff --git a/marked/Y/T-REC-Y.2812-201207-I_PDF-E/69b7bd65e85cdef6fdd7fb0a8194257c_img.jpg b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/69b7bd65e85cdef6fdd7fb0a8194257c_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..e126778374d74c32c34976156100211bc5d81c7d --- /dev/null +++ b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/69b7bd65e85cdef6fdd7fb0a8194257c_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:21f2dc5f97069b98f6658728b320bb1a1e9b8a3120c2fbd58fe13dc93df0ac1b +size 104429 diff --git a/marked/Y/T-REC-Y.2812-201207-I_PDF-E/79e1709a7317ead45379cbb8ff3ba802_img.jpg b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/79e1709a7317ead45379cbb8ff3ba802_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..80f4cd29304d12dba6d40643b8ca097813dfdad0 --- /dev/null +++ b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/79e1709a7317ead45379cbb8ff3ba802_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:5e78b897682e9fba7d7dc239795721d3ad385c93a49df38c51ae84da272954ba +size 127055 diff --git a/marked/Y/T-REC-Y.2812-201207-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..764a82687969ec15e48db91910bde9b62ee68cca --- /dev/null +++ b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:d2a1a0ee67a1cae8c705d7d87ae4ca44bf72d7e565432ceb25ccb352a8d78dc5 +size 6613 diff --git a/marked/Y/T-REC-Y.2812-201207-I_PDF-E/8c348bf9c2c81b018017ae1d19506a9a_img.jpg b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/8c348bf9c2c81b018017ae1d19506a9a_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..1868a87b4fd2e85dfb866f0b71738e70ceb9fe62 --- /dev/null +++ b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/8c348bf9c2c81b018017ae1d19506a9a_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:aeaa939c4cd73e99198a71ba14d434568d4bbc5f247bf5bd32e53062df172982 +size 146347 diff --git a/marked/Y/T-REC-Y.2812-201207-I_PDF-E/a149b400127a3e3e50b3c98d27c5935c_img.jpg b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/a149b400127a3e3e50b3c98d27c5935c_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..2f5fe184bdedd7dcdd5f856d58d3682f17da1445 --- /dev/null +++ b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/a149b400127a3e3e50b3c98d27c5935c_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:f73922ab37fd8f10b1b1bb49408211e978e76bc2cd2a356aa653946b82f46a50 +size 84061 diff --git a/marked/Y/T-REC-Y.2812-201207-I_PDF-E/a74294f34a0c736b7ee0f5f0cdca7e28_img.jpg b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/a74294f34a0c736b7ee0f5f0cdca7e28_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..3174f3581bc5cb2b084a4d90f32d7a8de96472c3 --- /dev/null +++ b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/a74294f34a0c736b7ee0f5f0cdca7e28_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:537980e17f10dce533326b042b54df8bc3616ab169aa6bc13afaf1416105e9ec +size 125949 diff --git a/marked/Y/T-REC-Y.2812-201207-I_PDF-E/c85ded401105f62f2d6ff26b3b5eb4af_img.jpg b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/c85ded401105f62f2d6ff26b3b5eb4af_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..557aa321386abf933808e5d2c078a7ba1785a27e --- /dev/null +++ b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/c85ded401105f62f2d6ff26b3b5eb4af_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:4d35c2541997bdb42da58d8859f9c8ffa6640467611831aed5b4f9408bdd1acf +size 110111 diff --git a/marked/Y/T-REC-Y.2812-201207-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..af02427d82a2c112443375d3700db638e43760c2 --- /dev/null +++ b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:f685b803612bd8357792d53661e03fd59115aacf6dabd2de68544e37d964034f +size 86583 diff --git a/marked/Y/T-REC-Y.2812-201207-I_PDF-E/ff7ce44f3fdd51bae7b231f34df07c6a_img.jpg b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/ff7ce44f3fdd51bae7b231f34df07c6a_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..89960ba9c6e3a5354d3a933f1927e1b160edf630 --- /dev/null +++ b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/ff7ce44f3fdd51bae7b231f34df07c6a_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:f2fe384def3beca3ccb874dbdd6b7c461dc2f237e395bdbe2c85cff4eeca0d2b +size 105930 diff --git a/marked/Y/T-REC-Y.2812-201207-I_PDF-E/raw.md b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..2ecb44d3add146718ffa4a53dc699c310a9aa29a --- /dev/null +++ b/marked/Y/T-REC-Y.2812-201207-I_PDF-E/raw.md @@ -0,0 +1,1079 @@ + + +I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +## Y.2812 + +(07/2012) + +SERIES Y: GLOBAL INFORMATION +INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS +AND NEXT-GENERATION NETWORKS + +Next Generation Networks – Generalized mobility + +# --- **Mobility management for interworking between WiMAX and UMTS** + +Recommendation ITU-T Y.2812 + +![ITU logo: A blue globe with red lightning bolts and the text 'ITU International Telecommunication Union'.](84a1d09fb489061482111515543b60dc_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with two red lightning bolts striking it. To the right of the globe, the text 'ITU' is written in a large, bold, blue font, and below it, the words 'International Telecommunication Union' are written in a smaller, blue font. + +ITU logo: A blue globe with red lightning bolts and the text 'ITU International Telecommunication Union'. + +# ITU-T Y-SERIES RECOMMENDATIONS **GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT- GENERATION NETWORKS** + +| | | +|--------------------------------------------------------------------|----------------------| +| GLOBAL INFORMATION INFRASTRUCTURE | | +| General | Y.100–Y.199 | +| Services, applications and middleware | Y.200–Y.299 | +| Network aspects | Y.300–Y.399 | +| Interfaces and protocols | Y.400–Y.499 | +| Numbering, addressing and naming | Y.500–Y.599 | +| Operation, administration and maintenance | Y.600–Y.699 | +| Security | Y.700–Y.799 | +| Performances | Y.800–Y.899 | +| INTERNET PROTOCOL ASPECTS | | +| General | Y.1000–Y.1099 | +| Services and applications | Y.1100–Y.1199 | +| Architecture, access, network capabilities and resource management | Y.1200–Y.1299 | +| Transport | Y.1300–Y.1399 | +| Interworking | Y.1400–Y.1499 | +| Quality of service and network performance | Y.1500–Y.1599 | +| Signalling | Y.1600–Y.1699 | +| Operation, administration and maintenance | Y.1700–Y.1799 | +| Charging | Y.1800–Y.1899 | +| IPTV over NGN | Y.1900–Y.1999 | +| NEXT GENERATION NETWORKS | | +| Frameworks and functional architecture models | Y.2000–Y.2099 | +| Quality of Service and performance | Y.2100–Y.2199 | +| Service aspects: Service capabilities and service architecture | Y.2200–Y.2249 | +| Service aspects: Interoperability of services and networks in NGN | Y.2250–Y.2299 | +| Numbering, naming and addressing | Y.2300–Y.2399 | +| Network management | Y.2400–Y.2499 | +| Network control architectures and protocols | Y.2500–Y.2599 | +| Packet-based Networks | Y.2600–Y.2699 | +| Security | Y.2700–Y.2799 | +| Generalized mobility | Y.2800–Y.2899 | +| Carrier grade open environment | Y.2900–Y.2999 | +| FUTURE NETWORKS | Y.3000–Y.3499 | +| CLOUD COMPUTING | Y.3500–Y.3999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# **Recommendation ITU-T Y.2812** + +# **Mobility management for interworking between WiMAX and UMTS** + +## **Summary** + +Recommendation ITU-T Y.2812 describes the mobility management framework for interworking between WiMAX and UMTS networks. The mobility management framework in this Recommendation focuses on vertical handover control in the transport stratum of next generation networks (NGNs) when a user equipment with multiple interfaces moves across those two different wireless access networks. The requirements, functional architecture and procedural information flows are given to specify the vertical handover control functionality. + +## **History** + +| Edition | Recommendation | Approval | Study Group | +|---------|----------------|------------|-------------| +| 1.0 | ITU-T Y.2812 | 2012-07-29 | 13 | + +## **Keywords** + +Mobility management, NGN, UMTS, vertical handover, WiMAX. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2013 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | | Page | +|---|---------------------------------------------------------------------------------|------| +| 1 | Scope ..... | 1 | +| 2 | References..... | 1 | +| 3 | Definitions ..... | 2 | +| | 3.1 Terms defined elsewhere..... | 2 | +| | 3.2 Terms defined in this Recommendation..... | 2 | +| 4 | Abbreviations and acronyms ..... | 2 | +| 5 | Conventions ..... | 4 | +| 6 | Requirements for WiMAX and UMTS interworking..... | 4 | +| | 6.1 Harmonization with IP-based core networks ..... | 4 | +| | 6.2 Service continuity ..... | 4 | +| | 6.3 QoS support ..... | 4 | +| | 6.4 Service compatibility..... | 5 | +| | 6.5 Service context transfer ..... | 5 | +| | 6.6 Interworking with the established AAA and security schemes..... | 5 | +| | 6.7 Policy-based and dynamic network selection..... | 5 | +| 7 | Functional architecture for interworking between WiMAX and UMTS..... | 5 | +| | 7.1 Access transport function ..... | 6 | +| | 7.2 Core transport function..... | 6 | +| | 7.3 Interworking for handover support..... | 7 | +| | 7.4 Seamless handover support ..... | 7 | +| 8 | Signal flow for interworking between WiMAX and UMTS ..... | 9 | +| | 8.1 Access network detection and selection ..... | 9 | +| | 8.2 Connection establishment..... | 10 | +| | 8.3 Vertical handover ..... | 13 | +| 9 | Security considerations ..... | 19 | +| | Appendix I – Use cases of hybrid MIP-based MM between WiMAX and UMTS ..... | 20 | +| | I.1 Introduction to hybrid mobile IP ..... | 20 | +| | I.2 Initial connection establishment procedure in the UMTS network..... | 21 | +| | I.3 Handover procedure from UMTS to WiMAX (make-before-break
scenario) ..... | 21 | +| | I.4 Initial connection establishment procedure in the WiMAX network..... | 22 | +| | I.5 Handover procedure from WiMAX to UMTS ..... | 23 | +| | Appendix II – Use cases of PMIPv6 with bicasting for vertical handovers ..... | 25 | +| | Bibliography..... | 27 | + +# **Introduction** + +This Recommendation describes the mobility management (MM) architecture between WiMAX and UMTS technologies in next generation networks (NGNs). This work has been motivated from the observation that NGN continues to evolve toward the accommodation of various wireless access technologies. Accordingly, it is required to specify the detailed architecture and procedures to practically apply the NGN MM framework to the environment accommodating those various access technologies. + +The MM architecture in this Recommendation is designed on the basis of the MM framework for NGN, which is described in the following Recommendations: + +- ITU-T Q.1707/Y.2804: Generic framework of mobility management for next generation networks [ITU-T Q.1707]; +- ITU-T Q.1708/Y.2805: Framework of location management for NGN [ITU-T Q.1708]; +- ITU-T Q.1709/Y.2806: Framework of handover control for NGN [ITU-T Q.1709]; +- ITU-T Y.2018: Mobility management and control framework and architecture within the NGN transport stratum [ITU-T Y.2018]. + +# Recommendation ITU-T Y.2812 + +# Mobility management for interworking between WiMAX and UMTS + +## 1 Scope + +This Recommendation describes the mobility management (MM) framework for interworking between WiMAX and UMTS networks where each access network would be operated by different service providers or different network management systems. In this Recommendation, the functional architecture focuses on IP mobility support for user equipment (UE) moving between those two different access networks. The functional architecture described in this Recommendation may be referred as a building block to be used to extend toward the other wireless access networks in next generation networks (NGNs). + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- | | | +|----------------|------------------------------------------------------------------------------------------------------------------------------------------| +| [ITU-T G.1000] | Recommendation ITU-T G.1000 (2001), Communications quality of service: A framework and definitions . | +| [ITU-T Q.1706] | Recommendation ITU-T Q.1706/Y.2801 (2006), Mobility management requirements for NGN . | +| [ITU-T Q.1707] | Recommendation ITU-T Q.1707/Y.2804 (2008), Generic framework of mobility management for next generation networks . | +| [ITU-T Q.1708] | Recommendation ITU-T Q.1708/Y.2805 (2008), Framework of location management for NGN . | +| [ITU-T Q.1709] | Recommendation ITU-T Q.1709/Y.2806 (2008), Framework of handover control for NGN . | +| [ITU-T Y.2001] | Recommendation ITU-T Y.2001 (2004), General overview of NGN . | +| [ITU-T Y.2011] | Recommendation ITU-T Y.2011 (2004), General principles and general reference model for Next Generation Networks . | +| [ITU-T Y.2012] | Recommendation ITU-T Y.2012 (2010), Functional requirements and architecture of next generation networks . | +| [ITU-T Y.2018] | Recommendation ITU-T Y.2018 (2009), Mobility management and control framework and architecture within the NGN transport stratum . | +| [ITU-T Y.2701] | Recommendation ITU-T Y.2701 (2007), Security requirements for NGN release 1 . | + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 functional architecture** [ITU-T Y.2012]: A set of functional entities and the reference points between them used to describe the structure of an NGN. These functional entities are separated by reference points, and thus, they define the distribution of functions. + +NOTE – The functional entities can be used to describe a set of reference configurations. These reference configurations identify which reference points are visible at the boundaries of equipment implementations and between administrative domains. + +**3.1.2 functional entity** [ITU-T Y.2012]: An entity that comprises an indivisible set of specific functions. Functional entities are logical concepts, while groupings of functional entities are used to describe practical, physical implementations. + +**3.1.3 host-based mobility management** [ITU-T Q.1707]: A mobility management scheme in which the MM signalling is performed based on (or controlled by) the user equipment (UE). + +**3.1.4 network-based mobility management** [ITU-T Q.1707]: A mobility management scheme in which the MM signalling is performed (or controlled) by the network entities, on behalf of the UE. + +**3.1.5 next generation network** [ITU-T Y.2001]: A packet-based network able to provide telecommunication services and able to make use of multiple broadband, QoS-enabled transport technologies and in which service-related functions are independent from underlying transport-related technologies. It enables unfettered access for users to networks and to competing service providers and/or services of their choice. It supports generalized mobility which will allow consistent and ubiquitous provision of services to users. + +**3.1.6 mobility** [ITU-T Q.1706]: The ability for the user or other mobile entities to communicate and access services irrespective of changes of the location or technical environment. + +**3.1.7 mobility management** [ITU-T Q.1706]: The set of functions used to provide mobility. These functions include authentication, authorization, location updating, paging, download of user information and more. + +**3.1.8 quality of service** [ITU-T G.1000]: The collective effect of service performances, which determine the degree of satisfaction of a user of the service. + +**3.1.9 transport stratum** [ITU-T Y.2011]: That part of the NGN which provides the user functions that transfer data and the functions that control and manage transport resources to carry such data between terminating entities (see also clause 7.1 of [ITU-T Y.2011]). + +## 3.2 Terms defined in this Recommendation + +None. + +# 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|--------|----------------------------------------------| +| AAA | Authentication, Authorization and Accounting | +| ABG-FE | Access Border Gateway Functional Entity | +| AN | Access Network | +| AN-FE | Access Node Functional Entity | +| AP | Access Point | + +| | | +|---------|----------------------------------------------------| +| AR-FE | Access Relay Functional Entity | +| ASN | Access Service Network | +| BBM | Break-Before-Make | +| BCE | Binding Cache Entry | +| BS | Base Station | +| CCoA | Co-located CoA | +| CMIP | Client Mobile IP | +| CN | Correspondent Node | +| CoA | Care-of-Address | +| DHCP | Dynamic Host Configuration Protocol | +| GGSN | Gateway GPRS Supporting Node | +| GPRS | General Packet Radio Service | +| HA | Home Agent | +| HDC-FE | Handover Decision and Control Functional Entity | +| HoA | Home Address | +| IBG-FE | Interconnection Border Gateway Functional Entity | +| IMSI | International Mobile Subscriber Identity | +| IP | Internet Protocol | +| L2HE-FE | Layer 2 Handover Execution Functional Entity | +| L3HEF | Layer 3 Handover Execution Function | +| LMA | Local Mobility Anchor | +| MAG | Mobile Access Gateway | +| MBB | Make-Before-Break | +| MIH | Media Independent Handover | +| MIIS | MIH Information Server | +| MIP | Mobile IP | +| MLM-FE | Mobility Location Management Functional Entity | +| MM | Mobility Management | +| MMCF | Mobility Management and Control Function | +| MUE | Mobile UE | +| NACF | Network Attachment Control Function | +| NAC-FE | Network Access Configuration Functional Entity | +| NGN | Next Generation Network | +| NID-FE | Network Information Distribution Functional Entity | +| PDN | Packet Data Network | +| PDP | Packet Data Protocol | +| PMA | Proxy Mobile Agent | + +| | | +|--------|-------------------------------------------------| +| PMIP | Proxy MIP | +| PRRP | Proxy RRP | +| PRRQ | Proxy RRQ | +| QoS | Quality of Service | +| RNC | Radio Network Controller | +| RRP | Registration Reply | +| RRQ | Registration Request | +| SAE | System Architecture Evolution | +| SGSN | Serving GPRS Supporting Node | +| TUP-FE | Transport User Profile Functional Entity | +| UE | User Equipment | +| UMTS | Universal Mobile Telecommunications System | +| WiMAX | Worldwide Interoperability for Microwave Access | + +# **5 Conventions** + +None. + +# **6 Requirements for WiMAX and UMTS interworking** + +### **6.1 Harmonization with IP-based core networks** + +The NGN is envisaged to be IP-based. Accordingly, the mobility management (MM) protocols for NGN should be IP-based or, at least, well-harmonized with IP technology for its efficient and integrated operation in such future networks [ITU-T Q.1706]. + +In the NGN environment, various access networks could be interconnected to each other through the IP-based core network. Therefore, the MM architecture between WiMAX and UMTS networks also should be designed to be easily applied to IP-based networks and services. + +### **6.2 Service continuity** + +The MM architecture for WiMAX-UMTS interworking should support seamless handover control functions to maintain session continuity of a user equipment (UE) moving between different access networks (ANs). Furthermore, those handover control mechanisms should provide fast handovers to support non-real time and real time service continuity (e.g., file downloading, VoIP and video streaming). + +To support service continuity during a handover, a UE's attachment change between different ANs should be hidden to the service/application layer by IP-based MM mechanisms. It is also required to reduce the communication service disruption due to a handover into the range that does not terminate ongoing services. + +### **6.3 QoS support** + +The MM mechanisms for WiMAX-UMTS interworking could support QoS-guaranteed handovers to provide seamless real time multimedia services such as VoIP and IPTV, as well as conventional best-effort services. However, the required level of QoS could be different according to the types of ANs, service characteristics, user requirements and handover policy of operators. + +Occasionally, after detecting the presence of both WiMAX and UMTS networks, it should be possible for a user to choose to connect to one of the networks based on the QoS policies driven by service characteristics and user requirements. That is, a UE should be able to dynamically change its connection from one attachable AN to another according to the QoS level needed for a particular service (e.g., bandwidth availability, time delay, packet loss ratio, etc.). + +### **6.4 Service compatibility** + +To support a UE's mobility within a single AN, the operators are likely to use their own MM mechanisms designed for a specific access technology. Thus the MM mechanism for NGN must be able to effectively harmonize with those existing MM protocols for various ANs. Especially, the MM mechanism for WiMAX-UMTS interworking should be well harmonized with the existing intra-AN MM architectures for WiMAX and UMTS networks which were developed by other SDOs (e.g., 3GPP/3GPP2, WiMAX Forum, etc.). + +### **6.5 Service context transfer** + +When a UE moves across different ANs, the context information of ongoing sessions, including QoS level, security method, AAA mechanism and data compression type in use, might be helpful in performing a vertical handover. The information can be used to minimize the latency involved in handing the session over to new serving entities. The proper use of context transfer mechanism could substantially reduce the amount of overhead in the servers required to support QoS, security, AAA, and so on. + +### **6.6 Interworking with the established AAA and security schemes** + +The MM protocols for NGN must specify how a user (or UE) is authenticated, authorized, accounted and secured for services using the standard authentication, authorization and accounting (AAA) and security mechanisms. [ITU-T Q.1706]. + +Because the operators generally have their own AAA and security schemes for their access networks, the MM architecture for interworking between different access technologies in NGN should carefully consider the compatibility with those existing AAA and security schemes. + +### **6.7 Policy-based and dynamic network selection** + +The NGN could support a user to choose to connect to one of the attachable ANs based on QoS level, cost, security level, etc. When a UE moves between WiMAX and UMTS networks, the MM architecture for interworking between those networks should allow the UE to choose a target AN for handover according to the pre-defined user/operator policy or by the dynamic selection procedure. + +# **7 Functional architecture for interworking between WiMAX and UMTS** + +This clause describes the functional architecture for interworking between WiMAX and UMTS networks, which is harmonized with the NGN architecture. Figure 7-1 shows the high-level functional architecture to accommodate WiMAX and UMTS network components into the NGN MM architecture. The general NGN architecture shown has been simplified in order to better focus on the objectives of this Recommendation. + +![Figure 7-1: Functional architecture for interworking between WiMAX and UMTS. The diagram shows the NGN Control Plane at the top, containing Network Attachment Control Functions and Mobility Management Control Functions. Below this is the Access Transport Functions block, which includes the UE (with WiMAX I/F and UMTS I/F), AN-FE/AR-FE (with WiMAX BS and UMTS NodeB/RNC), and L2HE-FE. The Core Transport Functions block includes the EN-FE (with L3HEF, ASN G/W, and GGSN/SGSN), ABG-FE (with L3HEF), Core Packet Transport Functions, and IBG-FE (with L3HEF). Control connections (thin lines) link the control functions to the transport functions. Data connections (thick lines) show the flow from the UE through the access and core transport functions.](d4af765160d04ecef538e5066006dc77_img.jpg) + +Figure 7-1: Functional architecture for interworking between WiMAX and UMTS. The diagram shows the NGN Control Plane at the top, containing Network Attachment Control Functions and Mobility Management Control Functions. Below this is the Access Transport Functions block, which includes the UE (with WiMAX I/F and UMTS I/F), AN-FE/AR-FE (with WiMAX BS and UMTS NodeB/RNC), and L2HE-FE. The Core Transport Functions block includes the EN-FE (with L3HEF, ASN G/W, and GGSN/SGSN), ABG-FE (with L3HEF), Core Packet Transport Functions, and IBG-FE (with L3HEF). Control connections (thin lines) link the control functions to the transport functions. Data connections (thick lines) show the flow from the UE through the access and core transport functions. + +**Figure 7-1 – Functional architecture for interworking between WiMAX and UMTS** + +### 7.1 Access transport function + +The access transport functions manage a UE's attachment to each access network as well as collect and aggregate traffic from various access networks, and then merge them into the core transport network. These functions typically interact with the network attachment control functions (NACFs) and the mobility management and control function (MMCF) to support IP mobility in the transport stratum in NGN. + +#### 7.1.1 Access node functional entity (AN-FE) + +The access node functional entity (AN-FE) in the access network directly connects to UEs and terminates the first/last hop wireless link signals at the network side. Generally, it is located at layer 2 devices such as WiMAX base station (BS) or UMTS Node B/RNC. + +#### 7.1.2 Layer 2 handover execution functional entity (L2HE-FE) + +The layer 2 handover execution functional entity (L2HE-FE) takes access technology specific actions as required in order to preserve flow continuity during handover. The L2HE-FE completes handover execution in the direction toward a UE when it has determined that the UE has executed a handover. The L2HE-FE resides in the access transport functional block as specified in [ITU-T Y.2018]. + +#### 7.1.3 Edge node functional entity (EN-FE) + +The edge node functional entity (EN-FE) in the access transport functional block connects to core packet transport functions and terminates the layer 2 access sessions with the end-user functions. To connect the layer 2 sessions to IP-based core transport functions, it shall be a layer 3 device with IP forwarding capabilities such as the ASN gateway in WiMAX network or GGSN/SGSN in UMTS network. The EN-FE can optionally support media independent handover (MIH) functions to increase the efficiency of handover control. + +### 7.2 Core transport function + +The core transport functions are responsible for ensuring data transport throughout the core network. They can provide a means to differentiate the quality of data transport in the core network. These functions can also provide QoS support mechanisms dealing directly with user traffic, including buffer management, queuing and scheduling, packet filtering, traffic classification, marking, policing, shaping, gate control and firewall capability. + +#### **7.2.1 Interconnection border gateway functional entity (IBG-FE)** + +The interconnection border gateway functional entity (IBG-FE) is a packet gateway used to interconnect an operator's core transport network with another operator's core transport network that supports the packet-based services. There may be one or multiple IBG-FEs in a single core transport network according to its interconnection topology. + +#### **7.2.2 Access border gateway functional entity (ABG-FE)** + +The access border gateway functional entity (ABG-FE) is a packet gateway between an access network and a core transport network. It is used to mask a service provider's network from access networks through which end-user functions are accessing packet-based services. For example, the PDN gateway in 3GPP SAE architecture can be located at the ABG-FE's position in NGN. + +### **7.3 Interworking for handover support** + +For MM in NGN, the layer 3 handover execution function (L3HEF) resides in the access transport and core transport functional blocks. It performs the commands from the MMCF to: + +- execute tunnel set up, modification and takedown during handover; +- buffer user packets as required to preserve flow continuity during handover; +- following handover, encapsulate user packets received from the UE (at the tunnel lower end in the case of network-based mobility) or from correspondent nodes (at the tunnel upper end) and forward them through the tunnel; similarly, decapsulate packets received from the tunnel and forward them to the UE (at the tunnel lower end in the case of network-based mobility) or to the correspondent node (at the tunnel upper end) [ITU-T Y.2018]. + +### **7.4 Seamless handover support** + +The handover control scenarios can be classified into two methods according to the order of a release of the existing connection to the old network and an establishment of a new connection to the target network. The 'break-before-make (BBM)' scenario represents a handover procedure that a UE first releases its current connection and then makes a new connection with the target network of a handover. On the other hand, the 'make-before-break (MBB)' scenario establishes a new connection first before releasing the current one. The MBB scenario is typically used to achieve relatively faster and seamless handovers which may not suffer from service disruption. + +For seamless handover support in the BBM handover scenario, the packet buffering and forwarding scheme can be applied between two L3HEFs residing in the old and target networks. By forwarding packets from the old L3HEF to the target L3HEF, the UE may not experience packet loss after a handover. How to implement the packet buffering and forwarding scheme is not covered in this Recommendation. + +![Figure 7-2: Host-based seamless handover control architecture. The diagram shows a User Equipment (UE) at the top. Below it are two dashed boxes representing the 'Old Network' and the 'Target Network'. The 'Old Network' contains an 'EN-FE' and an 'MLM-FE(P)'. The 'Target Network' contains an 'MLM-FE(P)' and an 'EN-FE'. At the bottom is a box for 'MMCF'. The process steps are: 1. Handover Decision (UE to UE), 2. L2 Connection Establishment (UE to Target Network EN-FE), 3. Registration (L3) (UE to Target Network MLM-FE(P)), 4. Registration (L3) (Target Network MLM-FE(P) to MMCF), 5. Simultaneous Binding & Bi-casting (Optional) (MMCF to MMCF), 6. L2 Connection Release (UE to Old Network EN-FE), 7. Report (Old Network EN-FE to Old Network MLM-FE(P)), 8. Deregistration (L3, Optional) (Old Network MLM-FE(P) to MMCF).](4801720824e4b5e2361a5564f91cfb70_img.jpg) + +``` + +graph TD + UE[UE] + subgraph Old_Network [Old Network] + EN_FE1[EN-FE] + MLM_FE_P1[MLM-FE(P)] + end + subgraph Target_Network [Target Network] + MLM_FE_P2[MLM-FE(P)] + EN_FE2[EN-FE] + end + MMCF[MMCF] + + UE -- "1. Handover Decision" --> UE + UE -- "2. L2 Connection Establishment" --> EN_FE2 + UE -- "3. Registration (L3)" --> MLM_FE_P2 + MLM_FE_P2 -- "4. Registration (L3)" --> MMCF + MMCF -- "5. Simultaneous Binding & Bi-casting (Optional)" --> MMCF + UE -- "6. L2 Connection Release" --> EN_FE1 + EN_FE1 -- "7. Report" --> MLM_FE_P1 + MLM_FE_P1 -- "8. Deregistration (L3, Optional)" --> MMCF + +``` + +Figure 7-2: Host-based seamless handover control architecture. The diagram shows a User Equipment (UE) at the top. Below it are two dashed boxes representing the 'Old Network' and the 'Target Network'. The 'Old Network' contains an 'EN-FE' and an 'MLM-FE(P)'. The 'Target Network' contains an 'MLM-FE(P)' and an 'EN-FE'. At the bottom is a box for 'MMCF'. The process steps are: 1. Handover Decision (UE to UE), 2. L2 Connection Establishment (UE to Target Network EN-FE), 3. Registration (L3) (UE to Target Network MLM-FE(P)), 4. Registration (L3) (Target Network MLM-FE(P) to MMCF), 5. Simultaneous Binding & Bi-casting (Optional) (MMCF to MMCF), 6. L2 Connection Release (UE to Old Network EN-FE), 7. Report (Old Network EN-FE to Old Network MLM-FE(P)), 8. Deregistration (L3, Optional) (Old Network MLM-FE(P) to MMCF). + +**Figure 7-2 – Host-based seamless handover control architecture** + +Figure 7-2 illustrates the handover control architecture employing the MBB handover scenario in the host-based MM for interworking between WiMAX and UMTS networks. In this case, the UE establishes an L2 connection with the EN-FE in the target network while maintaining the existing L2 connection to the EN-FE in the old network. Therefore, the UE temporarily has two L2 connections at the same time. In the host-based MM architecture, the L3 registration for vertical handover control is initiated by the UE and handled by MLM-FE Proxy (MLM-FE(P)) in the target network. This L3 registration process is also performed while the existing L3 mobility location binding in the old network is being maintained by MMCF. + +To achieve better handover performance, the simultaneous binding and bi-casting schemes can be applied with a support of the MMCF (optional). Those schemes allow the UE to temporarily receive packets both through the old and target networks so that packet losses during a handover are considerably reduced. How to implement those schemes is not within the scope of this Recommendation. + +Another option to enhance the handover control procedure is an explicit deregistration of the useless L3 mobility location binding for the old network after the UE releases the existing L2 connection to the old network. Deletion of the useless binding information can be implicitly performed by the timeout/refresh mechanism. Otherwise, if the timeout/refresh mechanism is not applied to the simultaneous binding information's lifetime, the explicit deregistration may be needed to reduce the waste of network resources due to unnecessary packet bi-casting after completion of the handover procedure. + +![Figure 7-3: Network-based seamless handover control architecture. The diagram shows a UE at the top, connected to two networks: Old Network and Target Network. The Old Network contains an EN-FE and an MLM-FE(P). The Target Network contains an MLM-FE(P) and an EN-FE. The MMCF is at the bottom. The process steps are: 1. Handover Decision (UE to UE), 2. L2 Connection Establishment (UE to Target Network EN-FE), 3. Report (Target Network EN-FE to Target Network MLM-FE(P)), 4. Registration (L3) (Target Network MLM-FE(P) to MMCF), 5. Simultaneous Binding & Bi-casting (Optional) (MMCF to MMCF), 6. L2 Connection Release (UE to Old Network EN-FE), 7. Report (Old Network EN-FE to Old Network MLM-FE(P)), 8. Deregistration (L3, Optional) (Old Network MLM-FE(P) to MMCF).](33ed1f9b27c7c21c797aa928b0f06851_img.jpg) + +``` + +graph TD + UE[UE] + subgraph Old_Network [Old Network] + EN_FE1[EN-FE] + MLM_FE1_P[MLM-FE(P)] + end + subgraph Target_Network [Target Network] + MLM_FE2_P[MLM-FE(P)] + EN_FE2[EN-FE] + end + MMCF[MMCF] + + UE -- "1. Handover Decision" --> UE + UE -- "2. L2 Connection Establishment" --> EN_FE2 + EN_FE2 -- "3. Report" --> MLM_FE2_P + MLM_FE2_P -- "4. Registration (L3)" --> MMCF + MMCF -- "5. Simultaneous Binding & Bi-casting (Optional)" --> MMCF + UE -- "6. L2 Connection Release" --> EN_FE1 + EN_FE1 -- "7. Report" --> MLM_FE1_P + MLM_FE1_P -- "8. Deregistration (L3, Optional)" --> MMCF + +``` + +Figure 7-3: Network-based seamless handover control architecture. The diagram shows a UE at the top, connected to two networks: Old Network and Target Network. The Old Network contains an EN-FE and an MLM-FE(P). The Target Network contains an MLM-FE(P) and an EN-FE. The MMCF is at the bottom. The process steps are: 1. Handover Decision (UE to UE), 2. L2 Connection Establishment (UE to Target Network EN-FE), 3. Report (Target Network EN-FE to Target Network MLM-FE(P)), 4. Registration (L3) (Target Network MLM-FE(P) to MMCF), 5. Simultaneous Binding & Bi-casting (Optional) (MMCF to MMCF), 6. L2 Connection Release (UE to Old Network EN-FE), 7. Report (Old Network EN-FE to Old Network MLM-FE(P)), 8. Deregistration (L3, Optional) (Old Network MLM-FE(P) to MMCF). + +**Figure 7-3 – Network-based seamless handover control architecture** + +Figure 7-3 depicts the handover control architecture employing the MBB handover scenario in the network-based MM for interworking between WiMAX and UMTS networks. The architecture is quite similar to that of the host-based MM case shown in Figure 7-2. The only difference is that the L3 mobility location binding registration for the target network is initiated by the MLM-FE(P). To do this, the EN-FE in the target network sends the MLM-FE(P) a report triggering an L3 handover procedure when the UE establishes a new L2 connection. + +## **8 Signal flow for interworking between WiMAX and UMTS** + +### **8.1 Access network detection and selection** + +How a multi-mode mobile UE (MUE) detects various attachable networks (i.e., WiMAX and UMTS networks) is not specified here. It may depend on the specific wireless access technology or the manufacturer's implementation of the terminal device. However, in frequent situations, a multi-mode MUE may have to decide which will be the target network for a new L2 connection establishment or imminent vertical handover. + +[ITU-T Y.2018] specifies that the network discovery and decision procedure must be performed before a MUE's handover to a new access point (AP) or network. The network discovery can be triggered by multiple reasons such as link deterioration, user request, network provider's intervention, etc. The network discovery procedure is generally performed by the MUE when it detects alternative APs to which it may move. + +The decision for initial attachment or handover decision may be based on information such as radio signal strength, resource availability in candidate networks and the applicable MUE-specific policy specified in the user mobility service profile. Such decision must consider three cases: + +- the network makes the handover decision with input from the MUE; +- the MUE makes the handover decision with the assistance of information from the network; +- the MUE makes the handover decision without assistance from the network. + +When the MUE is acting together with the network, the handover decision process begins when the MUE reports a list of alternative APs (i.e., node B/RNC in UMTS network and WiMAX BS) to the handover decision and control functional entity (HDC-FE) in the MMCF. Based on the information from the MUE, the HDC-FE requests the resource admission and control function (RACF) to check network resource availability on the potential path through each candidate network and receives the check result from the RACF. The HDC-FE then responds to the MUE, indicating its choice of deciding entity and triggering entity. If it has chosen the MUE to make the decision, it returns a candidate AP list which is based on the MN's input but reflects the results of the resource check and perhaps of local policy. If it has chosen to make the decision itself, its response includes no candidates. + +The next step depends on which entity the HDC-FE has nominated to make the handover decision. If it is the HDC-FE, then the HDC-FE retrieves static network information for the candidate APs from the network information distribution functional entity (NID-FE). Based on the information, it makes a final decision on the identity of the target AP. Then it informs the MUE of its decision. The MUE responds when it is ready for the handover. Otherwise, if the MUE is the one to make the decision, the MUE retrieves static network information about the target networks from the NID-FE. It makes its selection, and then informs the HDC-FE of the decision. + +After the MUE or the HDC-FE decides the target network for a handover, it may establish a proactive resource reservation through the target network by interworking with the RACF. The MM architecture in [ITU-T Y.2018] supports proactive resource reservation to provide seamless QoS after the MUE's handover. The resource check result from the RACF includes the information of resource availability in each candidate AP. With this information, the MUE or the HDC-FE requests the RACF to proactively reserve resources in the target network. Thereafter, the MN may activate the proactive resource reservation immediately after a handover in order to utilize a QoS-guaranteed path. This will significantly reduce the QoS degradation incurred by a handover when compared to the case of establishing a reactive resource reservation after completing the handover control procedure. + +### **8.2 Connection establishment** + +#### **8.2.1 Initial connection establishment to UMTS network** + +As shown in Figure 8-1, the initial L2 connection establishment procedure of a dual-mode MUE in the UMTS network is not different from that of a single-mode MUE moving within the UMTS network. On the network side, however, the MLM-FE proxy (MLM-FE(P)) initiates the MM procedure to support the dual-mode MUE's inter-AN mobility. The MLM-FE is a logical functional entity in MMCF which is defined in [ITU-T Y.2018]. A central instance of the MLM-FE (MLM-FE(C)) is generally located in the NGN core network while a proxy instance of the MLM-FE (MLM-FE(P)) could be typically co-located with a gateway node of each access network (e.g., GGSN/SGSN in UMTS network and ASN gateway in WiMAX network). + +1. To initiate the L3 MM procedure, the MLM-FE should be triggered differently depending on whether the network employs a host-based or network-based MM procedure. + - In the network-based MM (Case 1), after a request to create a PDP context for the MUE (including the MUE's persistent IP address allocation) is accepted, the NACF sends an indication message to the MLM-FE(P) to notify the need of network-based initial registration procedure with the MMCF. + - In the host-based MM (Case 2), the MUE first sends a Mobility Location Binding Update message to the MLM-FE(P) to trigger the initial registration procedure with the MMCF. + +2. To perform the MUE's L3 registration, as described in [ITU-T Y.2018], the MLM-FE(P) sends a Mobility Location Binding Registration/Update Request message to the MLM-FE(C) of the MMCF in the NGN control plane. The message needs to include a user/UE identifier authenticated for mobility services. To do this, the MLM-FE(P) may retrieve an L2 identifier, for example, an international mobile subscriber identity (IMSI) number of the MUE from Access Request and Access Accept messages exchanged between the GGSN and the NACF. In the network-based MM (Case 1), the MUE's L2 identifier can be delivered by an indication message from the NACF, which initiates the network-based MM procedure. +3. Upon receiving a Mobility Location Binding Registration/Update Request message from the MLM-FE(P), the MLM-FE(C) allocates the MUE's temporary IP address as specified in [ITU-T Y.2018]. Subsequently, MLM-FE(C) records the binding information of the MUE (i.e., mapping among the MUE's L2 identifier, persistent and temporary IP addresses) and responds to the MLM-FE(P) with a Mobility Location Binding Registration/Update Response message. +4. After the initial registration procedure is completed, the MUE can send and receive IP packets through the UMTS network. + +![Sequence diagram of Figure 8-1 showing the initial connection establishment procedure to a UMTS network. It involves interactions between the MUE, UMTS Network components (NodeB/RNC, SGSN, GGSN, AAA), NACF, DHCP, and MMCF. The flow includes L2 connection, PDP context activation, authentication, IP allocation, and two mobility management options: Option 1 (Network-based MM) and Option 2 (Host-based MM).](c85ded401105f62f2d6ff26b3b5eb4af_img.jpg) + +``` + +sequenceDiagram + participant MUE + participant NodeB_RNC as NodeB/ RNC + participant SGSN + participant GGSN as GGSN (MLM-FE(P)) + participant AAA as AAA (TAA-FE/TUP-FE) + participant NACF as NAC-FE/TLM-FE + participant DHCP + participant MMCF as MMCF (MLM-FE(C)) + + MUE ->> NodeB_RNC: L2 Connection Establishment + MUE ->> SGSN: Activate PDP Context Request + SGSN ->> AAA: Authentication & Authorization + SGSN ->> GGSN: Create PDP Context Request + GGSN ->> NACF: Access Request/Accept + NACF ->> DHCP: Persistent IP Allocation + GGSN ->> SGSN: Create PDP Context Response + SGSN ->> MUE: Activate PDP Context Accept (IP configuration) + + rect rgb(240, 240, 240) + Note over GGSN, NACF: