1、 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 Y.2083 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (08/2014) SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS Next Generation Networks Frameworks and functional archite
2、cture models Multimedia telephony over distributed service networking Recommendation ITU-T Y.2083 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 m
3、iddleware Y.200Y.299 Network aspects 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.
4、1100Y.1199 Architecture, access, network 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 IPT
5、V over NGN Y.1900Y.1999 NEXT GENERATION 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.
6、2250Y.2299 Enhancements to NGN 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 CLO
7、UD COMPUTING Y.3500Y.3999 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T Y.2083 (08/2014) i Recommendation ITU-T Y.2083 Multimedia telephony over distributed service networking Summary Recommendation ITU-T Y.2083 describes the distributed service networking (DSN)
8、functional architecture intended to support multimedia telephony (MMTel) services based on the DSN service requirements. The main objective of this Recommendation is to define a high level MMTel service architecture over DSN and a set of capabilities and information flows which support MMTel service
9、s. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T Y.2083 2014-08-29 13 11.1002/1000/12280 Keywords Distributed service networking, DSN, multimedia telephony, MMTel. _ * To access the Recommendation, type the URL http:/handle.itu.int/ in the address field of your web browser
10、, followed by the Recommendations unique ID. For example, http:/handle.itu.int/11.1002/1000/11830-en. ii Rec. ITU-T Y.2083 (08/2014) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication tec
11、hnologies (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 Tele
12、communication 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 a
13、reas of information technology which fall within ITU-Ts 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 o
14、perating 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 “s
15、hall“ 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 RIGHTSITU draws attention to the possibility that the p
16、ractice 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 dev
17、elopment 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 ther
18、efore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2015 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.2083 (08/2014) iii Table of Contents Page 1 Scope .
19、 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 3 6 Functional architecture . 3 7 Basic communication procedures . 4 7.1 Application level procedures 4 7.2 Overlay level procedures 7 8 Overloa
20、d control considerations in MMTel . 17 8.1 Overload control flows by using a backup node 17 8.2 Overload control by initiating a node joining . 22 9 Supplementary services support . 22 10 Mobility support . 22 11 Interworking . 22 12 Charging . 23 13 Security considerations . 23 14 Network managemen
21、t . 23 Bibliography. 24 Rec. ITU-T Y.2083 (08/2014) 1 Recommendation ITU-T Y.2083 Multimedia telephony over distributed service networking 1 Scope This Recommendation specifies a cost-effective, flexible, scalable and reliable system which provides multimedia telephony (MMTel) services to users conn
22、ected to a distributed service networking (DSN) network. It describes the requirements and functional architecture for supporting MMTel services over DSN, defines detailed information flows related to MMTel service provisioning, node management and overload control. It also describes the support for
23、 supplementary services, mobility, interworking, charging, and network management in an MMTel system over DSN. 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
24、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
25、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 Gener
26、ation Networks. 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), Fra
27、mework 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.2012 Recommendation ITU-T Y.2012 (2010), Functional requirements and architecture of next generation networks. ITU-T Y.2080 Recommendation ITU-T Y.2080 (2012)
28、, Functional architecture for distributed service networking. ITU-T Y.2173 Recommendation ITU-T Y.2173 (2008), Management of performance measurement for NGN. ITU-T Y.2206 Recommendation ITU-T Y.2206 (2010), Requirements for distributed service networking capabilities. ITU-T Y.2211 Recommendation ITU
29、-T Y.2211 (2007), IMS-based real-time conversational multimedia services over NGN. ITU-T Y.2233 Recommendation ITU-T Y.2233 (2010), Requirements and framework allowing accounting and charging capabilities in NGN. 2 Rec. ITU-T Y.2083 (08/2014) 3 Definitions 3.1 Terms defined elsewhere This Recommenda
30、tions uses the following terms defined elsewhere: 3.1.1 control node b-ITU-T Y Suppl.10: A DSN node which provides service control and transport control functionalities. 3.1.2 distributed service networking ITU-T Y.2206: An overlay network which provides distributed and manageable capabilities to su
31、pport various multimedia services. 3.1.3 DSN node ITU-T Y.2206: A node used in DSN providing distributed functionalities, including distributed routing and distributed storage. 3.1.4 functional entity ITU-T Y.2012: An entity that comprises an indivisible set of specific functions. Functional entitie
32、s are logical concepts, while groupings of functional entities are used to describe practical, physical implementations. 3.1.5 user profile ITU-T Y.2080: In the context of the DSN functional architecture, a collection of information that specifies the subscribed services and access privileges relate
33、d to a DSN service user. The data in the user profile is called user profile data. NOTE A user profile may include the following attributes: user ID and other data related to authentication and authorization, user preferences, service status, service class, usage and/or contribution information, or
34、subscriber accounting characteristics, etc. 3.2 Terms defined in this Recommendation This Recommendation defines the following terms: 3.2.1 admitting node: During the process of node joining, the admitting node of the joining node is responsible for the portion of the namespace which will reside in
35、the joining node. 3.2.2 bootstrap node: During the process of node joining, the bootstrap node of the joining node is the node that the joining node contacts. The bootstrap node validates the joining nodes credentials and forwards the connecting request from the joining node to its admitting node. 3
36、.2.3 proxy node: The proxy node of user equipment (UE) is the first contact point of UE. The proxy node locates the serving node and forwards session control messages between the serving node and UE. 3.2.4 responsible node: During the process of node leaving, the responsible node of the leaving node
37、 is the node that should take over the portion of the namespace that the leaving node is currently responsible for. 3.2.5 serving node: The serving node of UE is the DSN node which processes session control messages from UE. It is responsible for a range of user profile storage, and supports user au
38、thentication, session initiation and termination. NOTE The different descriptions of nodes are a relative concept; the DSN node is homogenous, and a node may act as different kinds of nodes depending on different sessions, different joining nodes, etc. For example, a node may act as a serving node t
39、o a certain end-user function (EF), but may also act as a proxy node to another EF. Rec. ITU-T Y.2083 (08/2014) 3 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: DSN Distributed Service Networking EF End-user Function ID Identification IMS IP Multimedi
40、a Subsystem MMTel Multimedia Telephony NEF Node Enrolment Function NGN Next Generation Network P2P Peer-to-Peer QoS Quality of Service RLF Resource Location Function SCF Service Control Function SIP Session Initiation Protocol UE User Equipment 5 Conventions Within this Recommendation, the keywords
41、“multimedia telephony“ and “MMTel“ indicate the same service as “IP multimedia subsystem (IMS) based real time conversational multimedia services“ defined in ITU-T Y.2211. 6 Functional architecture Figure 6-1 depicts a functional architecture, based on the distributed service networking (DSN) archit
42、ecture of ITU-T Y.2080, which can be used to support multimedia telephony (MMTel) services. The service control function (SCF) includes registration, authentication, authorization, media resources controlling and service user profiles, and it interacts with the resource location function (RLF) for r
43、esource location. All the DSN nodes in the MMTel service overlay have the same functional capabilities, including RLF and SCF. DSN nodes need to be enrolled by a node enrolment function (NEF) to construct the MMTel service overlay. The related functions and reference points are identified in ITU-T Y
44、.2080. 4 Rec. ITU-T Y.2083 (08/2014) Y . 2 0 8 3 (1 4 )_ F 6 -1D SN M M tel o v erl a y N EFC2EFC6Co n t ro lMan ag em en tC8C1D SN no deD SN no de MFC1D SN no de (pr o x y no de)R LFC2C7SC FD SN no de (s erv i ng no de)R LFC2C7SC FFigure 6-1 MMTel service architecture over DSN 7 Basic communication
45、 procedures The MMTel service allows multimedia conversational communications between two or more users. It provides for the real-time bidirectional conversational transfer of voice, video or optionally other types of data. The MMTel communication is point to point between communicating terminals, o
46、r between a terminal and a network entity. This communication is usually symmetric, but in special cases the media components present in each direction may be different, or they may be the same, but with different bit rates and quality of service (QoS). Normally, the MMTel communication service is r
47、ealised by a session control protocol. According to whether a session control function is included, the procedures for MMTel communication can be categorized as application level procedures and overlay level procedures. The application level procedures consist of the user registration and session re
48、lated procedures such as session initiation and session termination (release). The overlay level procedures contain the node management procedures which include node joining and node leaving. 7.1 Application level procedures This clause describes the DSN application level procedures which implement
49、the basic communication services including user registration, session initiation and session release. NOTE 1 The term “user“ in the following procedure represents DSN user equipment (UE). The end-user function (EF) is a most primary function of DSN UE, which supports access to the DSN overlay network and service by exchanging session initiation protocol (SIP) messages with the SCF of a proxy node. UE may also include other functions. The detailed procedures are described as follow
