1、 International Telecommunication Union ITU-T Y.1920TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (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 mechan
2、isms in support of IPTV services Recommendation ITU-T Y.1920 ITU-T Y-SERIES RECOMMENDATIONS GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS GLOBAL INFORMATION INFRASTRUCTURE General Y.100Y.199 Services, applications and middleware Y.200Y.299 Network aspects
3、Y.300Y.399 Interfaces and protocols Y.400Y.499 Numbering, addressing and naming Y.500Y.599 Operation, administration and maintenance Y.600Y.699 Security Y.700Y.799 Performances Y.800Y.899 INTERNET PROTOCOL ASPECTS General Y.1000Y.1099 Services and applications Y.1100Y.1199 Architecture, access, netw
4、ork capabilities and resource management Y.1200Y.1299 Transport Y.1300Y.1399 Interworking Y.1400Y.1499 Quality of service and network performance Y.1500Y.1599 Signalling Y.1600Y.1699 Operation, administration and maintenance Y.1700Y.1799 Charging Y.1800Y.1899 IPTV over NGN Y.1900Y.1999NEXT GENERATIO
5、N NETWORKS Frameworks and functional architecture models Y.2000Y.2099 Quality of Service and performance Y.2100Y.2199 Service aspects: Service capabilities and service architecture Y.2200Y.2249 Service aspects: Interoperability of services and networks in NGN Y.2250Y.2299 Numbering, naming and addre
6、ssing Y.2300Y.2399 Network management Y.2400Y.2499 Network control architectures and protocols Y.2500Y.2599 Packet-based Networks Y.2600Y.2699 Security Y.2700Y.2799 Generalized mobility Y.2800Y.2899 Carrier grade open environment Y.2900Y.2999 FUTURE NETWORKS Y.3000Y.3499 CLOUD COMPUTING Y.3500Y.3999
7、 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T Y.1920 (07/2012) i 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
8、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-
9、29 13 ii Rec. ITU-T Y.1920 (07/2012) 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
10、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 top
11、ics 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-Ts purview, the necessary standards are pre
12、pared 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 m
13、ay 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
14、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
15、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 notic
16、e 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 http:/www.itu.int/ITU-T/ipr/. ITU 20
17、13 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T Y.1920 (07/2012) iii 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 Recomm
18、endation 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
19、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
20、. 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 Tra
21、ffic 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 Appendi
22、x V Cross-layer interaction for IPTV services 23 Bibliography. 24 Rec. ITU-T Y.1920 (07/2012) 1 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-
23、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
24、 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 ex
25、pected 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
26、 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 Recomme
27、ndations 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 p
28、ublished. 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 fra
29、mework 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
30、 (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. 2 Rec. ITU-T Y.1920 (07/2012) 3.2 Term defined in this Recommendation None. 4 Abbreviations and acronyms This Recommendation
31、 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 Net
32、work 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 I
33、P 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
34、Open Shortest Path First Rec. ITU-T Y.1920 (07/2012) 3 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 o
35、ver 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 Cla
36、use 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
37、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-
38、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
39、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 suppo
40、rt 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. 4 Rec. ITU-T Y.1920 (07/2012) FR 6.2.1-03: The traffic management mechanisms are
41、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 mec
42、hanisms 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 managemen
43、t 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 differ
44、ent 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 manage
45、ment 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
46、 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 scheduli
47、ng 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 Rec. ITU-T Y.1920 (07/2012) 5 Table 1 Mapping table among requiremen
48、ts, 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 F
49、R 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, an
