1、 INTERNATIONAL TELECOMMUNICATION UNION ITU-T Y.2001TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (12/2004) SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS Next Generation Networks Frameworks and functional architecture models General overview of
2、NGN ITU-T Recommendation Y.2001 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 Y.300Y.399 Interfaces and pro
3、tocols 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, network capabilities and resource
4、 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 NEXT GENERATION NETWORKS Frameworks and functional architecture model
5、s 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 addressing Y.2300Y.2399 Network management Y.2400Y.2499 Netw
6、ork control architectures and protocols Y.2500Y.2599 Security Y.2700Y.2799 Generalized mobility Y.2800Y.2899 For further details, please refer to the list of ITU-T Recommendations. ITU-T Rec. Y.2001 (12/2004) i ITU-T Recommendation Y.2001 General overview of NGN Summary Considering new market realit
7、ies characterized by factors such as: open competition among operators due to deregulation of markets, explosion of digital traffic, e.g., due to the increasing use of “the Internet“, increasing demand for new multimedia services, increasing demand for a general mobility, convergence of networks and
8、 services, etc., the NGN (Next Generation Network) is conceived as a concrete implementation of the GII (Global Information Infrastructure). Recommendations in the Y series provide the foundation of the Next Generation Networks (NGN). However, implementation issues were not adequately addressed in G
9、II. As a consequence, the NGN should be understood as the further step in the realization of GII concept. The target of NGN is to ensure that all elements required for interoperability and network capabilities support applications globally across the NGN while maintaining the concept of separation b
10、etween transport, services and applications. This Recommendation is intended to be used as background information to assist the development of Recommendations, standards and of implementation guidelines for the realization of Next Generation Networks. Source ITU-T Recommendation Y.2001 was approved
11、on 17 December 2004 by ITU-T Study Group 13 (2005-2008) under the ITU-T Recommendation A.8 procedure. Keywords Decoupling between transport and service, generalized mobility, GII, NGN, overview. ii ITU-T Rec. Y.2001 (12/2004) FOREWORD The International Telecommunication Union (ITU) is the United Nat
12、ions 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 telecommunica
13、tions 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
14、 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 telecommu
15、nication 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 ma
16、ndatory 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 draw
17、s 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
18、 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 repr
19、esent the latest information and are therefore strongly urged to consult the TSB patent database. ITU 2005 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. ITU-T Rec. Y.2001 (12/2004) iii CONTENTS Page 1 Scope a
20、nd purpose 1 2 References. 1 2.1 ITU-T references 1 2.2 IETF references 2 3 Definitions 2 4 Abbreviations 2 5 Objectives of the NGN . 3 6 Fundamental characteristics of NGN . 3 7 NGN capabilities 4 8 Areas of key importance. 4 8.1 General framework and architectural principles 5 8.2 Architecture mod
21、els for the NGN 5 8.3 End-to-end Quality of Service 5 8.4 Service platforms 5 8.5 Network management. 6 8.6 Security. 6 8.7 Generalized mobility 7 8.8 Network control architecture(s) and protocols. 8 8.9 Service capabilities and service architecture 8 8.10 Interoperability of services and network in
22、 NGN 8 8.11 Numbering, naming and addressing. 9 8.12 Disaster and relief communications capabilities 10 iv ITU-T Rec. Y.2001 (12/2004) Introduction The concept of an NGN (Next Generation Network) has been introduced to take into consideration the new realities in the telecommunications industry, cha
23、racterized by factors such as: competition among operators due to ongoing deregulation of markets, explosion of digital traffic, e.g., increasing use of “the Internet“, increasing demand for new multimedia services, increasing demand for a general mobility, convergence of networks and services, etc.
24、 ITU-T has already initiated standardization of the new generation of networks with the Global Information Infrastructure (GII) Project which produced a number of GII Recommendations in the Y series. However, implementation issues were not in the scope of the GII. As a result, GII Recommendations ha
25、ve to be complemented by additional specifications and implementation guidelines for concrete realizations. A major goal of the NGN is to facilitate convergence of networks and convergence of services. The common understanding is that the NGN has to be seen as the concrete realization of concepts de
26、fined for the GII. ITU-T Rec. Y.2001 (12/2004) 1 ITU-T Recommendation Y.2001 General overview of NGN 1 Scope and purpose A number of ITU-T standardization activities are related to the establishment of implementation guidelines, standards and Recommendations for the realization of a Next Generation
27、Network. The major task of the NGN activities is to ensure that all elements required for interoperability and network capabilities to support applications globally across the NGN are addressed by ITU-T standardization activities. This Recommendation is intended to help and to be used as background
28、information to assist the development of Recommendations, Standards and of implementation guidelines for the realization of the Next Generation Networks. This is to ensure that all elements required for interoperability and network capabilities to support applications globally across NGN are adequat
29、ely addressed by ITU-T standardization activities. The use of this Recommendation is not restricted solely to the ITU Members. The scope of this Recommendation is to give a general overview of what constitutes and defines a Next Generation Network (NGN). More specifically, this Recommendation identi
30、fies the fundamental characteristics and capabilities that an NGN should be able to support. 2 References 2.1 ITU-T 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
31、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 li
32、st 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 Y.100 (1998), General overview of the Global Information Infrastructure s
33、tandards development. 2 ITU-T Recommendation Y.110 (1998), Global Information Infrastructure principles and framework architecture. 3 ITU-T Recommendation Y.130 (2000), Information communication architecture. 4 ITU-T Recommendation Y.140 (2000), Global Information Infrastructure (GII) Reference poin
34、ts for interconnection framework. 5 ITU-T Recommendation Y.140.1 (2004), Guideline for attributes and requirements for interconnection between public telecommunication network operators and service providers involved in provision of telecommunication services. 6 ITU-T Recommendation X.200 (1994), In
35、formation technology Open Systems Interconnection Basic Reference Model: The basic model. 7 ITU-T Recommendation G.805 (2000), Generic functional architecture of transport networks. 8 ITU-T Recommendation G.809 (2003), Functional architecture of connectionless layer networks. 2 ITU-T Rec. Y.2001 (12
36、/2004) 9 ITU-T Recommendation M.3030 (2002), Telecommunications Markup Language (tML) framework. 10 ITU-T Recommendation H.248.1 (05/2002), Gateway control protocol: Version 2. 11 ITU-T Recommendation E.164 (1997), The international public telecommunication numbering plan. 12 ITU-T Recommendation H.
37、323 (2003), Packet-based multimedia communications systems. 2.2 IETF references 13 IETF RFC 3261 (2002), SIP: Session Initiation Protocol. 3 Definitions This Recommendation defines the following terms: 3.1 Next Generation Network (NGN): A packet-based network able to provide telecommunication servic
38、es 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 choi
39、ce. It supports generalized mobility which will allow consistent and ubiquitous provision of services to users. 3.2 generalized mobility: 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
40、of service availability may depend on several factors including the Access Network capabilities, service level agreements between the users home network and the visited network (if applicable), etc. Mobility includes the ability of telecommunication with or without service continuity. 4 Abbreviation
41、s This Recommendation uses the following abbreviations. 3G Third Generation Wireless Systems API Application Programming Interface DNS Domain Name System GII Global Information Infrastructure GPRS General Packet Radio Service GSM Global System for Mobile communications ISDN Integrated Services Digit
42、al Network NAPT Network Address Port Translation NGN Next Generation Network OSA Open Service Access PC Personal Computer PSTN Public Switched Telephone Network QoS Quality of Service SDO Standards Development Organization SIP Session Initiation Protocol tML telecommunications Markup Language UMTS U
43、niversal Mobile Telecommunications System ITU-T Rec. Y.2001 (12/2004) 3 UPT Universal Personal Telecommunication URI Unified Resource Identifier URL Unified Resource Locator VHE Virtual Home Environment WLAN Wireless Local Area Network 5 Objectives of the NGN NGN should fulfil the requirement of the
44、 environment described in ITU-T Recs Y.100 1, Y.110 2, Y.130 3 and Y.140 4 or Y.140.1 5, for example to: promote fair competition; encourage private investment; define a framework for architecture and capabilities to be able to meet various regulatory requirements; provide open access to networks; w
45、hile: ensuring universal provision of and access to services; promoting equality of opportunity to the citizen; promoting diversity of content, including cultural and linguistic diversity; recognizing the necessity of worldwide cooperation with particular attention to less developed countries. 6 Fun
46、damental characteristics of NGN The term NGN as defined in clause 3 is commonly used to give a name to the changes to the service provision infrastructures that have already started in the telecommunication industry. The NGN can be further defined by the following fundamental characteristics: packet
47、-based transfer; separation of control functions among bearer capabilities, call/session, and application/ service; decoupling of service provision from transport, and provision of open interfaces; support for a wide range of services, applications and mechanisms based on service building blocks (in
48、cluding real time/ streaming/ non-real time and multimedia services); broadband capabilities with end-to-end QoS (Quality of Service); interworking with legacy networks via open interfaces; generalized mobility (see 3.2 and 8.7); unrestricted access by users to different service providers; a variety
49、 of identification schemes; unified service characteristics for the same service as perceived by the user; converged services between fixed/mobile; independence of service-related functions from underlying transport technologies; support of multiple last mile technologies; compliant with all regulatory requirements, for example concerning emergency communications, security, privacy, lawful interception, etc. 4 ITU-T Rec. Y.2001 (12/2004) 7 NGN capabilities NGN shall provide the
