1、 International Telecommunication Union ITU-T Y.2012TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (04/2010) SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS Next Generation Networks Frameworks and functional architecture models Functional requireme
2、nts and architecture of next generation networks Recommendation ITU-T Y.2012 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
3、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.1100Y.1199 Architectu
4、re, 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 IPTV over NGN Y.1900Y.19
5、99 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.2250Y.2299 Numbering,
6、 naming and addressing Y.2300Y.2399 Network management Y.2400Y.2499 Network control architectures and protocols Y.2500Y.2599 Future networks Y.2600Y.2699 Security Y.2700Y.2799 Generalized mobility Y.2800Y.2899 Carrier grade open environment Y.2900Y.2999 For further details, please refer to the list
7、of ITU-T Recommendations. Rec. ITU-T Y.2012 (04/2010) i Recommendation ITU-T Y.2012 Functional requirements and architecture of next generation networks Summary The objective of Recommendation ITU-T Y.2012 is to describe the functional requirements and architecture of the next generation network (NG
8、N), taking into account the requirements and capabilities for ITU-T NGN as described in Recommendation ITU-T Y.2201. The functional architecture provided in this Recommendation allows a clear distinction between the definition and specification aspects of services provided by the NGN, and the actual
9、 specification of the network technologies used to support those services. In line with Recommendation ITU-T Y.2011 principles, an implementation-independent approach is adopted. History Edition Recommendation Approval Study Group 1.0 ITU-T Y.2012 2006-09-13 13 1.1 ITU-T Y.2012 (2006) Cor. 1 2008-01
10、-25 13 1.2 ITU-T Y.2012 (2006) Amend. 1 2008-01-25 13 2.0 ITU-T Y.2012 2010-04-30 13 Keywords Functional architecture, functional entities, NGN. ii Rec. ITU-T Y.2012 (04/2010) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommun
11、ications, 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 telecommunic
12、ations 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 procedur
13、e laid down in WTSA Resolution 1. In some areas 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 telecomm
14、unication 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
15、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 dr
16、aws 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
17、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 repres
18、ent the latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2010 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.2012 (04/201
19、0) iii CONTENTS Page 1 Scope 1 2 References. 1 3 Definitions 3 3.1 Terms defined elsewhere 3 3.2 Terms defined in this Recommendation . 4 4 Abbreviations and acronyms 5 5 Conventions 10 6 General principles of the NGN functional architecture 11 6.1 General characteristics 11 6.2 Connectivity to the
20、NGN 12 7 Overview of the NGN architecture . 13 7.1 Transport stratum functions 15 7.2 Service stratum functions . 17 7.3 End-user functions 18 7.4 Management functions . 18 7.5 Identity management (IdM) functions 19 8 NGN concepts . 20 8.1 Mobility levels in the NGN architecture 20 8.2 NGN service a
21、rchitecture . 20 8.3 Network topology hiding functions and NAPT traversal functions . 21 8.4 Overload control . 21 8.5 Charging and accounting functions (CAF) . 22 9 Generalized NGN functional architecture 25 9.1 NGN functional architecture framework 25 9.2 NGN functional entities (FEs) 26 9.3 Funct
22、ional entity descriptions . 27 9.4 Reference points . 52 10 NGN components . 57 10.1 NGN service-specific components . 59 10.2 NGN transport-specific components 60 10.3 Management functions . 60 11 Security considerations . 60 Annex A Differences between this edition and the 2006 edition of Recommen
23、dation ITU-T Y.2012 61 iv Rec. ITU-T Y.2012 (04/2010) Page Annex B Support of IPTV services 62 B.1 Overall functional mapping between NGN-based IPTV and NGN architectures 62 B.2 IMS-based IPTV functional architecture 63 B.3 Non-IMS-based IPTV architecture . 65 Appendix I Examples of NGN network conf
24、igurations 68 I.1 Configurations and topology of the NGN 68 I.2 Relationship between the NGN and administrative domains . 70 I.3 Relationship between the NGN and service domains 72 I.4 Enterprise role model . 73 I.5 Functional roles 75 Appendix II Transport-stratum access network scenarios 77 II.1 I
25、ntroduction 77 II.2 Scenario 1: Multi-layered transport stratum . 77 II.3 Scenario 2: Access aggregation using layer-2 78 II.4 Scenario 3: Access aggregation using layer-3 79 II.5 Scenario 4: Multistage policy enforcement 80 II.6 Scenario 5: Partitioning into transport-layer traffic subdomains . 81
26、Appendix III Instantiation of NGN reference points 82 III.1 Introduction 82 III.2 Scope 82 III.3 Rationale to consider SNI . 82 III.4 Instantiation of NGN reference points . 82 Appendix IV Example illustrative deployment scenario for IdM in NGN . 85 Bibliography. 87 Rec. ITU-T Y.2012 (04/2010) 1 Rec
27、ommendation ITU-T Y.2012 Functional requirements and architecture of next generation networks 1 Scope The objective of this Recommendation is to describe the functional requirements and architecture of the next generation network (NGN) ITU-T Y.2001 taking into account the requirements and capabiliti
28、es for ITU-T NGN as described in ITU-T Y.2201. This Recommendation defines functional entities (FEs) of the NGN and is a precursor to further identifying and designating reference points, and defining information flows across such reference points. The functional architecture provided in this Recomm
29、endation allows a clear distinction between the definition/specification aspects of services provided by the NGN and the actual specification of the network technologies used to support those services. In line with ITU-T Y.2011 principles, an implementation-independent approach is adopted. This Reco
30、mmendation describes the functional architecture of the NGN by using the generic definitions, symbols, and abbreviations that are defined in related ITU-T Recommendations. Although the scope of this Recommendation is targeted primarily at an NGN architecture, it is clear that the accommodation of le
31、gacy PSTN/ISDN terminals and/or interworking with the PSTN/ISDN is an important consideration with respect to NGN deployment. Thus, to provide a more comprehensive view, certain functional elements required to accommodate PSTN/ISDN terminals and interworking with the PSTN/ISDN are shown/described ev
32、en though they are not strictly part of the NGN architecture itself. This Recommendation provides support for nomadism between different network termination points as well as transport level mobility. Administrations may require network operators and service providers to take into account national r
33、egulatory and national policy requirements in implementing this Recommendation. Note that Annex A provides a high-level description of the main additional features provided in this Recommendation as compared to the 2006 edition of this Recommendation. 2 References The following ITU-T Recommendations
34、 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 en
35、couraged 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
36、document, the status of a Recommendation. ITU-T G.722 Recommendation ITU-T G.722 (1988), 7 kHz audio-coding within 64 kbit/s. ITU-T G.8010 Recommendation ITU-T G.8010/Y.1306 (2004), Architecture of Ethernet layer networks. ITU-T M.1400 Recommendation ITU-T M.1400 (2006), Designations for interconnec
37、tions among operators networks. ITU-T M.3060 Recommendation ITU-T M.3060/Y.2401 (2006), Principles for the Management of the Next Generation Networks. 2 Rec. ITU-T Y.2012 (04/2010) ITU-T Q.1706 Recommendation ITU-T Q.1706/Y.2801 (2006), Mobility management requirements for NGN. ITU-T Y.101 Recommend
38、ation ITU-T Y.101 (2000), Global Information Infrastructure terminology: Terms and definitions. 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.1453 Recommendation ITU-T Y.1453 (2006), TDM-IP interworking user
39、plane interworking. 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.2001 Recommendation ITU-T Y.2001 (2004), General overview of NGN. ITU-T Y.2011 Recommendation ITU
40、-T Y.2011 (2004), General principles and general reference model for Next Generation Networks. ITU-T Y.2014 Recommendation ITU-T Y.2014 (2010), Network attachment control functions in next generation networks. ITU-T Y.2017 Recommendation ITU-T Y.2017 (2009), Multicast functions in next generation ne
41、tworks. 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.2021 Recommendation ITU-T Y.2021 (2006), IMS for Next Generation Networks. ITU-T Y.2031 Recommendation ITU-T Y.2031 (2006), PSTN/ISDN emulatio
42、n architecture. ITU-T Y.2091 Recommendation ITU-T Y.2091 (2008), Terms and definitions for Next Generation Networks. ITU-T Y.2111 Recommendation ITU-T Y.2111 (2008), Resource and admission control functions in Next Generation Networks. ITU-T Y.2171 Recommendation ITU-T Y.2171 (2006), Admission contr
43、ol priority levels in Next Generation Networks. ITU-T Y.2173 Recommendation ITU-T Y.2173 (2008), Management of performance measurement for NGN. ITU-T Y.2201 Recommendation ITU-T Y.2201 (2009), Requirements and capabilities for ITU-T NGN. ITU-T Y.2233 Recommendation ITU-T Y.2233 (2008), Requirements
44、and framework allowing accounting and charging capabilities in NGN. ITU-T Y.2234 Recommendation ITU-T Y.2234 (2008), Open service environment capabilities for NGN. ITU-T Y.2701 Recommendation ITU-T Y.2701 (2007), Security requirements for NGN release 1. ITU-T Y.2702 Recommendation ITU-T Y.2702 (2008
45、), Authentication and authorization requirements for NGN release 1. Rec. ITU-T Y.2012 (04/2010) 3 ITU-T Y.2720 Recommendation ITU-T Y.2720 (2009), NGN identity management framework. 3 Definitions 3.1 Terms defined elsewhere This Recommendation uses the following terms defined elsewhere: 3.1.1 applic
46、ation ITU-T Y.101: A structured set of capabilities, which provide value-added functionality supported by one or more services. 3.1.2 content provider ITU-T Y.1910: The entity that owns or is licensed to sell content or content assets. 3.1.3 control plane ITU-T Y.2011: The set of functions that cont
47、rols the operation of entities in the stratum or layer under consideration, plus the functions required to support this control (see clause 8.1.1 of ITU-T Y.2011 for some details). 3.1.4 data plane ITU-T Y.2011: The set of functions used to transfer data in the stratum or layer under consideration.
48、3.1.5 identity management ITU-T Y.2720: Set of functions and capabilities (e.g., administration, management and maintenance, discovery, communication exchanges, correlation and binding, policy enforcement, authentication and assertions) used for: assurance of identity information (e.g., identifiers,
49、 credentials, attributes), assurance of the identity of an entity (e.g., users/subscribers, groups, user devices, organizations, network and service providers, network elements and objects, and virtual objects), and enabling business and security applications. 3.1.6 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
