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 Series Q TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Supplement 64 (02/2014) SERIES Q: SWITCHING AND SIGNALLING Physical realization of next generation networks ITU-T Q-series Recommendations Supplement 64 ITU-T Q-SERIE
2、S RECOMMENDATIONS SWITCHING AND SIGNALLING SIGNALLING IN THE INTERNATIONAL MANUAL SERVICE Q.1Q.3 INTERNATIONAL AUTOMATIC AND SEMI-AUTOMATIC WORKING Q.4Q.59 FUNCTIONS AND INFORMATION FLOWS FOR SERVICES IN THE ISDN Q.60Q.99 CLAUSES APPLICABLE TO ITU-T STANDARD SYSTEMS Q.100Q.119 SPECIFICATIONS OF SIGN
3、ALLING SYSTEMS No. 4, 5, 6, R1 AND R2 Q.120Q.499 DIGITAL EXCHANGES Q.500Q.599 INTERWORKING OF SIGNALLING SYSTEMS Q.600Q.699 SPECIFICATIONS OF SIGNALLING SYSTEM No. 7 Q.700Q.799 Q3 INTERFACE Q.800Q.849 DIGITAL SUBSCRIBER SIGNALLING SYSTEM No. 1 Q.850Q.999 PUBLIC LAND MOBILE NETWORK Q.1000Q.1099 INTER
4、WORKING WITH SATELLITE MOBILE SYSTEMS Q.1100Q.1199 INTELLIGENT NETWORK Q.1200Q.1699 SIGNALLING REQUIREMENTS AND PROTOCOLS FOR IMT-2000 Q.1700Q.1799 SPECIFICATIONS OF SIGNALLING RELATED TO BEARER INDEPENDENT CALL CONTROL (BICC) Q.1900Q.1999 BROADBAND ISDN Q.2000Q.2999 SIGNALLING REQUIREMENTS AND PROT
5、OCOLS FOR THE NGN Q.3000Q.3999 For further details, please refer to the list of ITU-T Recommendations. Q series Supplement 64 (02/2014) i Supplement 64 to ITU-T Q-series Recommendations Physical realization of next generation networks Summary The next generation network (NGN) architecture defined in
6、 Recommendation ITU-T Y.2012 is a generalized architecture in which abstract functional entities are specified. However, to address the issues of interoperability within an NGN network, there is a need to identify physical realizations showing which functional entities are implemented in a network c
7、omponent and by implication the interfaces that are important to ensure the interoperability of systems. Supplement 64 to the ITU-T Q-series of Recommendations provides guidance on the physical realization of NGNs by describing a number of possible physical entities corresponding to a functional ent
8、ity or a group of functional entities specified in the generalized functional architecture of NGN. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T Q Suppl. 64 2014-02-21 11 11.1002/1000/12171 _ * To access the Recommendation, type the URL http:/handle.itu.int/ in the address
9、 field of your web browser, followed by the Recommendations unique ID. For example, http:/handle.itu.int/11.1002/1000/11830-en. ii Q series Supplement 64 (02/2014) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, in
10、formation 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 telecommunications on a
11、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 laid down
12、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 publication, the expression “Administration“ is used for conciseness to indicate both a telecommunication admin
13、istration and a recognized operating agency. Compliance with this publication is voluntary. However, the publication may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the publication is achieved when all of these mandatory provisions ar
14、e 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 publication is required of any party. INTELLECTUAL PROPERTY RIGHTSITU draws attention to the possib
15、ility that the practice or implementation of this publication 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 publi
16、cation development process. As of the date of approval of this publication, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this publication. However, implementers are cautioned that this may not represent the latest information and are
17、therefore 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. Q series Supplement 64 (02/2014) iii Table of Contents Page
18、1 Scope . 1 2 References . 1 3 Definitions 1 3.1 Terms defined elsewhere 1 3.2 Terms defined in this Supplement 1 4 Abbreviations and acronyms 1 5 Conventions 5 6 Next generation network architecture . 5 6.1 Overview 5 6.2 NGN functional architecture 8 7 Physical realization of the NGN functional ar
19、chitecture 23 Bibliography. 30 iv Q series Supplement 64 (02/2014) Introduction The NGN architecture defined in Recommendation ITU-T Y.2012 (2010) is a generalized architecture in which abstract functional entities are specified. However, to address the issues of interoperability within an NGN netwo
20、rk, there is a need to identify physical realizations showing which functional entities are implemented in a network component and by implication the interfaces that are important to ensure the interoperability of systems. This document is intended to give guidance on the physical realization of NGN
21、s by describing a number of possible physical entities corresponding to a functional entity or a group of functional entities specified in the generalized functional architecture of NGN. Clause 6 describes the NGN architecture and functions defined in terms of various functional entities and clause
22、7 gives examples of physical components in which these functional entities may be realized. Reference is made to Recommendation ITU-T Q.3900, which describes the mapping of NGN functional entities into physical components for the purpose of defining a model for the testing of NGN equipment and Suppl
23、ement 2 to Recommendation ITU-T Y.2012 that describes the realization of session border controllers (SBCs) in an NGN environment. More detailed information on NGN, in particular on the protocol mechanisms employed, can be found in the ITU-T Handbook on NGN “Converging Networks“. Q series Supplement
24、64 (02/2014) 1 Supplement 64 to ITU-T Q-series Recommendations Physical realization of next generation networks 1 Scope Supplement 64 to the ITU-T Q-series of Recommendations provides guidance on the physical realization of NGNs by describing a number of possible physical entities corresponding to a
25、 functional entity or a group of functional entities specified in the generalized functional architecture of NGN. 2 References References to documents made in this Supplement are found in the bibliography. 3 Definitions 3.1 Terms defined elsewhere This Supplement uses terms defined in b-ITU-T Y.2091
26、. 3.2 Terms defined in this Supplement None. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: 3GPP Third Generation Partnership Project ABG-FE Access Border Gateway Functional Entity AF-PE Application Function Physical Entity AGC-FE Access Gateway Contr
27、ol Functional Entity AM-FE Access Management Functional Entity AMF Account Management Function AMG-FE Access Media Gateway Functional Entity AN-FE Access Node Functional Entity ANI Application Network Interface APL-GW-FE Application Gateway Functional Entity APL-SCM-FE Application Service Coordinati
28、on Manager Functional Entity APP-FE Application provisioning functional entity AR-FE Access Relay Functional Entity AS Application Server AS-FE Application Support Functional Entity ASS-PE Application and Service Support Physical Entity 2 Q series Supplement 64 (02/2014) ASUP-FE Application Support
29、User Profile Functional Entity ATM Asynchronous Transfer Mode BGC-FE Breakout Gateway Control Functional Entity BS Billing System CCF Charging Collection Function CD-PE Content Distribution Physical Entity CD authentication prior to, or during, the IP address allocation procedure; authorization base
30、d on user profiles (e.g., access transport subscription); access network configuration based on user profiles; and may, in addition, provide the addresses of NGN Service stratum components such as an IP multimedia subsystem (IMS) proxy call/session control function (P-CSCF) to the customer premises
31、equipment (CPE). The resource and admission control function (RACF) acts as the arbitrator for resource negotiation and allocation between the service control and transport functions within the NGN architecture. SCFs supporting various NGN services interact with the RACF to provide capabilities for
32、the control of NGN transport resources. Resource reservation, admission control and gate control can be used to provide an appropriate QoS for specific information flows and it is possible to control network address and port translation (NAPT) and firewall traversal. The RACF interacts with transpor
33、t functions to control one or more of the following functionalities in the transport stratum: packet filtering; traffic classification, marking and policing; bandwidth reservation and allocation; prevention of IP address spoofing; NAPT, firewall traversal; and usage metering. Q series Supplement 64
34、(02/2014) 7 Admission control can be performed on the basis of authorization checks based on user profiles, service level agreements (SLAs), operator specific policy rules, and the availability of resources within the access and core transport networks. The RACF also interacts with the NACF to confi
35、gure parameters; perform network access registration, authentication and authorization; and to check user profiles against SLAs. At present, similar services are offered to users on both fixed access networks and on mobile networks. A major feature of NGN is generalized mobility in which services ar
36、e consistently realized to a user independent of network access technology. The mobility management and control functions (MMCFs) support IP-based mobility within the transport stratum. The service stratum comprises SCFs. These are typically registration, authentication and authorization functions a
37、t the service level, session control and resource control coordination. An illustration of how the various services are supported is given in Figure 2. Figure 2 NGN components The service control layer includes IMS support. IMS was initially developed by the 3rd Generation Partnership Project (3GPP)
38、 for non-voice applications, such as Presence and Push-to-talk, and was then adopted by ETSI TISPAN and the ITU-T as a session control mechanism for voice and other services, such as Internet protocol television (IPTV), in NGN. IMS is extended in NGN to support 8 Q series Supplement 64 (02/2014) add
39、itional access network types such as digital subscriber line (xDSL) and wireless local area network (WLAN). IMS is a system specification based on the use of the session initiation protocol (SIP) defined by the IETF. In addition, SIP user-network interface (UNI) and network-network interface (NNI) s
40、ignalling profiles have been defined to ensure interoperability of equipment at these interfaces. The content delivery functions (CDFs) receive content from the application and service support functions (for IPTV for example) and then store, process, and deliver this content under control of the SCF
41、s to the end-user using the capabilities of the transport functions. Identity management (IdM) is the set of functions and capabilities used for the assurance of identity information (e.g., identifiers, credentials or attributes) and of the identity of an entity (e.g., users/subscribers, groups, use
42、r devices, organizations, network and service providers, network elements and objects, and virtual objects). The NGN functional entities controlling policy, sessions, media, resources, service delivery, security, etc., may be distributed over the infrastructure. When they are physically distributed,
43、 they communicate over open interfaces. Interworking between the NGNs of different operators and between NGNs and existing networks, such as the public switched telephone network (PSTN), integrated services digital network (ISDN) and the global system for mobile communications (GSM), is provided by
44、means of gateways. 6.2 NGN functional architecture The NGN functional architecture is defined in b-ITU-T Y.2012 (2010). Functional entities are described to realize access and core packet transport; network access control, resource and admission control, mobility management; service control and cont
45、ent delivery; application and service support; identity management; charging and end-user CPE capabilities. The functional architecture is dissected and its components described in more detail in the following clauses. 6.2.1 Transport stratum 6.2.1.1 Access and core transport functions The access ne
46、twork includes functions for the connection of user equipment to the network using a variety of technologies (such as cable, xDSL, wireless and optical) and also the aggregation of traffic from a number of users. For example, b-ITU-T Y.Sup6 describes how the DSL technology defined by the DSL Forum (
47、now the Broadband Forum) can be used for NGN access. QoS control mechanisms, such as buffer management, queuing, scheduling, packet filtering, traffic classification, marking, policing and shaping, are supported in the access and core transport sections. The processing functional entities of the tra
48、nsport stratum are shown in Figure 3. Q series Supplement 64 (02/2014) 9 Q Su p p l. 6 4 (1 4 ) 03_FT- : 22 L a ye r 2ha nd ov e re xe c ut i on F ET - 2: A c c e s sno de F EA c c e s st r an s po r tf un c t i on sT - 3: E dg eno de F ET - 5: A c c e s sbo r de rga t e w a y F ET - 4: A c c e s sr
49、 e l a y F ET - 9: S i gn a l l i ngga t e w a y F ET - 8: M e di ar e s ou r c epr oc e s s i ng F EC or e t r an s po r tf un c t i on sT - 6: I nt e r c on ne c t i onbo r de r ga t e w a y F ET - 7: T r un ki ngm e di a ga t e w a y F EA c c e s s t r an s p or t p r oc e s s i n g C or e t r an s p or t p r oc e s s i n gT - 1: A c c e s sm e di aga t e w a y F ET C - T 1T - U 2T - U 3T - O N 1T - U 1T - O N 2T - O N 3T - U 4( N ot e 1)T C - T 2( N ot e 2)T C - T 3 S 2-T T C - T 7T C - T 8( N ot e 3)T C - T
