1、 International Telecommunication Union ITU-T Y.2262TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (12/2006) SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS Next Generation Networks Service aspects: Interoperability of services and networks in NGN
2、PSTN/ISDN emulation and simulation ITU-T Recommendation Y.2262 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 aspect
3、s 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, ne
4、twork 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 NEXT GENERATION NETWORKS Frameworks an
5、d 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 addressing Y.2300Y.2399 Netwo
6、rk management Y.2400Y.2499 Network 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.2262 (12/2006) i ITU-T Recommendation Y.2262 PSTN/ISDN emulation and simula
7、tion Summary ITU-T Recommendation Y.2262 describes principle aspects of evolving PSTN/ISDN to NGN. It discusses emulation and simulation of PSTN/ISDN. Emulation provides PSTN/ISDN service capabilities and interfaces using adaptation to an IP infrastructure while simulation provides PSTN/ISDN-like se
8、rvice capabilities using session control over IP interfaces and infrastructure. Source ITU-T Recommendation Y.2262 was approved on 14 December 2006 by ITU-T Study Group 13 (2005-2008) under the ITU-T Recommendation A.8 procedure. Keywords Emulation, ISDN, NGN, PSTN, simulation. ii ITU-T Rec. Y.2262
9、(12/2006) 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 ques
10、tions 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 Recommendation
11、s 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 prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation,
12、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 a
13、pplicability) 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 wi
14、th 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 appl
15、icability 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 impl
16、ement 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 2007 All rights reserved. No part of this publication may be reproduced, by any m
17、eans whatsoever, without the prior written permission of ITU. ITU-T Rec. Y.2262 (12/2006) iii 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 3 6 PSTN/ISDN evolution to NGN
18、4 6.1 PSTN/ISDN emulation and simulation 4 6.2 Interfaces 5 6.3 Adaptations. 6 7 Aspects to consider. 6 7.1 Transport. 6 7.2 Signalling and control. 6 7.3 Management . 7 7.4 Services. 7 7.5 Operation, administration and maintenance (OAM) 9 7.6 Naming, numbering and addressing. 9 7.7 Accounting, char
19、ging and billing . 9 7.8 Interworking . 10 8 Service requirements by national regulatory bodies. 11 9 Emergency telecommunications in NGN . 11 10 Security aspects of evolution 12 Appendix I PSTN/ISDN emulation and simulation scenarios 13 I.1 Emulation scenarios 13 I.2 Simulation scenarios. 13 I.3 Le
20、gacy and NGN user equipment connected through an NGN . 15 I.4 Scenarios involving interworking. 15 I.5 Emulation and simulation scenarios involving customer networks . 17 Appendix II Examples of emulation and simulation network structure . 18 II.1 Examples of emulation and simulation network structu
21、re . 18 II.2 Basic connection patterns. 18 Appendix III Examples of signalling protocols for emulation and simulation. 20 III.1 Signalling for PSTN/ISDN emulation 20 III.2 Signalling for PSTN/ISDN simulation. 20 Appendix IV Examples of emulation of PSTN and N-ISDN bearer services 22 Appendix V Billi
22、ng system evolution scenarios. 23 Bibliography. 24 ITU-T Rec. Y.2262 (12/2006) 1 ITU-T Recommendation Y.2262 PSTN/ISDN emulation and simulation 1 Scope The public switched telephone network/integrated services digital network (PSTN/ISDN) being one of the first telecommunication networks, is consider
23、ed to be a prime candidate for evolution to Next Generation Networks (NGN). The PSTN/ISDN provides many features that a service provider can offer to the end-users. As such, when evolving to NGN, there is the expectation that all or at least some of these features may continue to be provided. The PS
24、TN/ISDN emulation could potentially provide PSTN/ISDN service capabilities and interfaces and maintain the end-user experience unchanged irrespective of the changing of the core network. PSTN/ISDN simulation could potentially provide PSTN/ISDN-like service capabilities that fulfil the end-users need
25、. However, there is no guarantee that PSTN/ISDN simulation can provide all features that have been available to the PSTN/ISDN user. Simulated PSTN/ISDN may provide additional new features and capabilities that have not been available to the users of PSTN/ISDN. This Recommendation describes PSTN/ISDN
26、 emulation and simulation. 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 refere
27、nces 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 t
28、o a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. ITU-T G.964 ITU-T Recommendation G.964 (2001), V-interfaces at the digital local exchange (LE) V5.1 interface (based on 2048 kbit/s) for the support of access network (AN). ITU-T G.96
29、5 ITU-T Recommendation G.965 (2001), V-interfaces at the digital local exchange (LE) V5.2 interface (based on 2048 kbit/s) for the support of access network (AN). ITU-T I.411 ITU-T Recommendation I.411 (1993), ISDN user-network interfaces Reference configurations. ITU-T I.413 ITU-T Recommendation I.
30、413 (1993), B-ISDN user-network interface. ITU-T I.610 ITU-T Recommendation I.610 (1999), B-ISDN operation and maintenance principles and functions. ITU-T Q.1741.4 ITU-T Recommendation Q.1741.4 (2005), IMT-2000 references to release 6 of GSM evolved UMTS core network. ITU-T Y.1411 ITU-T Recommendati
31、on Y.1411 (2003), ATM-MPLS network interworking Cell mode user plane interworking. ITU-T Y.1541 ITU-T Recommendation Y.1541 (2006), Network performance objectives for IP-based services. 2 ITU-T Rec. Y.2262 (12/2006) ITU-T Y.1710 ITU-T Recommendation Y.1710 (2002), Requirements for Operation between
32、an IP user equipment and the public IP network; analogue telephone interface between the legacy user equipment and PSTN/ISDN; S, T or coincident S/T reference point for ISDN basic rate via a network termination 1 (NT1) ITU-T I.411; 6 ITU-T Rec. Y.2262 (12/2006) SB, TBor coincident SB/TBreference poi
33、nt for ISDN primary rate via a network termination 1 (NT1) ITU-T I.413; access networks using access nodes (e.g., multiplexer, concentrator) with V5 signalling, PSTN interface provided according to national mappings, V5.1 ITU-T G.964 and V5.2 ITU-T G.965 interfaces for support of access network (AN)
34、; national variants of the above. Interface type 2, IF2: This is a network-network interface (NNI). It can be between: NGNs; an NGN and the PSTN/ISDN; an NGN and a public IP network; an NGN and public land mobile network (PLMN). 6.3 Adaptations The adaptation function may be implemented in the acces
35、s gateway or the residential gateway. This function interfaces to IP multimedia component using SIP and to PSTN/ISDN terminals, and provides PSTN/ISDN emulation and simulation services. This function contains both a media gateway function and a media gateway controller function and supports the prov
36、ision of voice-based services to analogue lines and ISDN lines. The function is “call control aware“ (due to the termination of SIP) as opposed to “call control agnostic“ H.248-based access media gateways. Adaptation function type 1 (ADF1): ADF1 allows the NGN to provide a full NGN account, includin
37、g user and service profiles, to the user equipment. From an NGN perspective, the user is receiving a normal NGN service that is essentially indistinguishable from any other NGN service. (As is the case with all NGN services, in practical implementations it is still subject to limitations of the user
38、 equipment). ADF1 is typically implemented in a residential gateway. Adaptation function type 2 (ADF2): ADF2 allows the user equipment to receive a standard PSTN/ISDN service, which is essentially indistinguishable from the PSTN/ISDN service provided by legacy technologies. From an NGN perspective,
39、a “PSTN/ISDN emulation“ service is being provided. In general, user and service profiles will not be associated with this account. ADF2 is typically implemented in access gateway. 7 Aspects to consider 7.1 Transport Transport is an important part of any network. It encompasses functions related to:
40、user premises equipments (e.g., terminals, PBXs, routers); the access network equipments (e.g., line terminating modules, remote or local concentrators, multiplexers); and the core network equipments (e.g., local exchanges, transmission facilities, transit and international exchanges). All transport
41、-related aspects, which may be affected by evolution to NGN, should be considered. 7.2 Signalling and control PSTN/ISDN uses signalling systems such as analogue line signalling, channel-associated signalling (CAS) like signalling systems R1 b-ITU-T Q.310-Q.332, R2 b-ITU-T Q.400-Q.490, and common cha
42、nnel signalling (CCS) like SS7 or DSS1 b-ITU-T Q.931. All these signalling systems are for the circuit switched networks. Since NGN transport is packet-based (and call and bearer are decoupled), other suitable types of signalling (e.g., BICC, SIP-I b-ITU-T Q.1912.5, etc.) may be ITU-T Rec. Y.2262 (1
43、2/2006) 7 required. Also, the signalling function and the call control function may reside in more than one NGN element. Since the NGN has to work with the PSTN/ISDN and other networks, interworking between NGN signalling systems and the legacy network signalling systems is required. Signalling aspe
44、cts within the next generation corporate network shall remain independent from NGN access or core network signalling. It is further anticipated that signalling aspects for access and core networks be independent in order to have the possibility of a step-wise approach for evolution to NGN. Examples
45、of signalling for PSTN/ISDN emulation and simulation are provided in Appendix III. 7.3 Management The management system of PSTN/ISDN includes exchange network management, access network management, intelligent network management and operation support system (OSS). b-ITU-T M.3010 and b-ITU-T M.3400 p
46、rovide management principles for PSTN/ISDN. Referring to the management module defined in the telecommunication management network (TMN), the NGN management system is comprised of three planes, namely the network element management plane, the network control plane and the service management plane. T
47、he three planes each implement corresponding management functions to each layer in the NGN layered model. Standard interfaces between these planes will be defined. 7.4 Services In this clause, bearer services, teleservices and supplementary services are discussed. It is also anticipated that PSTN/IS
48、DN emulation and simulation would support both narrow-band and broadband services to the extent possible. 7.4.1 Bearer service 7.4.1.1 Overview While evolving from PSTN/ISDN to NGN, continuity of bearer services should be provided. In this Recommendation, only bearer services defined for PSTN and na
49、rrow-band ISDN (N-ISDN) are discussed. Bearer services are inherently characterized by transport and lower layer capabilities. It is inevitable to have different bearer services in the NGN environment when simulating or emulating PSTN and ISDN bearer services. This fact is indicated by the terms “simulation“ and “emulation“. The principal difference is primarily a result of intrinsic differences concerning grade of service (GoS) and QoS properties related to the bearer technology.
