1、 International Telecommunication Union ITU-T Y.2054TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (02/2008) SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS Next Generation Networks Frameworks and functional architecture models Framework to support
2、 signalling for IPv6-based NGN Recommendation ITU-T Y.2054 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.
3、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, networ
4、k 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 and fu
5、nctional 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 Network m
6、anagement 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. Rec. ITU-T Y.2054 (02/2008) i Recommendation ITU-T Y.2054 Framework to support signalling fo
7、r IPv6-based NGN Summary Recommendation ITU-T Y.2054 specifies the features of signalling using Internet Protocol version 6 (IPv6), requirements, and interworking scenarios to support signalling in IPv6-based next generation network (NGN) environments. Source Recommendation ITU-T Y.2054 was approved
8、 on 29 February 2008 by ITU-T Study Group 13 (2005-2008) under Recommendation ITU-T A.8 procedure. Keywords IPv6, NGN, QoS, signalling. ii Rec. ITU-T Y.2054 (02/2008) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications,
9、 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 telecommunications on
10、 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 laid do
11、wn 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 telecommunication
12、 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 mandatory
13、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 draws attent
14、ion 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 others
15、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, implementers are cautioned that this may not represent th
16、e latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2009 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.2054 (02/2008) iii
17、 CONTENTS Page 1 Scope 1 2 References. 1 3 Definitions 1 3.1 Terms defined elsewhere 1 3.2 Terms defined in this Recommendation. 2 4 Abbreviations and acronyms 2 5 Conventions 3 6 Features of signalling using IPv6 . 3 6.1 Features of the existing signalling protocols 3 6.2 IPv6 features to support s
18、ignalling. 4 7 Requirements for signalling in IPv6-based NGN. 5 7.1 Requirements of signalling for transport and service control 6 7.2 Requirements of signalling for interworking . 6 8 Functional architecture to support signalling in IPv6-based NGN. 7 9 Scenarios for signalling interworking. 8 9.1 S
19、ignalling interworking scenarios between IPv6 and IPv4 8 9.2 Signalling interworking scenarios between IPv6-based NGN and other networks . 9 10 Security considerations. 10 Appendix I Implementation concerns related to signalling in IPv6-based NGN . 11 I.1 Router alert option within the hop-by-hop op
20、tion header 11 Appendix II Examples of signalling using IPv6 features in IPv6-based NGN. 12 II.1 Examples of signalling using IPv6 features from the transport control viewpoint 12 II.2 Examples of signalling using IPv6 features from the service control viewpoint 13 Bibliography. 15 Rec. ITU-T Y.2054
21、 (02/2008) 1 Recommendation ITU-T Y.2054 Framework to support signalling for IPv6-based NGN 1 Scope This Recommendation specifies the requirements and guidelines for supporting the existing signalling protocols and signalling for supporting several functions required in Internet Protocol version 6 (
22、IPv6)-based next generation networks (NGN) using the IPv6 features. This Recommendation covers the following: Features of signalling using IPv6 Requirements of signalling for transport/service control and interworking Functional architecture for signalling in IPv6-based NGN Signalling interworking s
23、cenarios between IPv6-based NGN and other networks The implementation methods for the delivery of signalling messages in IPv6 are not covered by this Recommendation. 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text, consti
24、tute 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 encouraged to investigate the possibility of applying the most recent edition of the Rec
25、ommendations 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 document, the status of a Recommendation. ITU-T Y.2012 Recommendation ITU-T Y.2012 (20
26、06), Functional requirements and architecture of the NGN release 1. ITU-T Y.2051 Recommendation ITU-T Y.2051 (2008), General overview of IPv6-based NGN. 3 Definitions 3.1 Terms defined elsewhere This Recommendation uses the following terms defined elsewhere: 3.1.1 IPv6-based NGN ITU-T Y.2051: This r
27、efers to NGN that supports addressing, routing, protocols, and services associated with IPv6. An IPv6-based NGN shall recognize and process the IPv6 headers and options, operating over various underlying transport technologies in the transport stratum. 3.1.2 service continuity b-ITU-T Q.1706: The ab
28、ility for a moving object to maintain ongoing service over including current states, such as users network environment and session for a service. 3.1.3 signalling b-ITU-T I.112: The exchange of information specifically concerned with the establishment and control of connections, and with management,
29、 in a telecommunication network. 3.1.4 signalling interworking b-ITU-T Q.300: Signalling interworking is the controlled transfer of signalling information across the interface between signalling systems where the significance of the transferred information is identical or where the significance is t
30、ranslated in a defined manner. 2 Rec. ITU-T Y.2054 (02/2008) 3.1.5 user b-ITU-T M.60: A person or a machine delegated by a customer to use the services and/or facilities of a telecommunications network. 3.2 Terms defined in this Recommendation This Recommendation defines the following terms: 3.2.1 f
31、low: This refers to a sequence of packets sent from a particular source to a particular destination where common routing is applied. When using IPv6, a flow is identified by IPv6 3-tuple including source/destination IP addresses and flow label. 3.2.2 flow label: The 20-bit field in the IPv6 header i
32、s used by a source to label the packets of a flow. This label identifies IPv6 packets with the same origin and destination. The identified packets can be treated equally in the network. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations: ANI Application-Network Interfa
33、ce CN Correspondent Node CoA Care-of-Address CR-LDP Constraint-based Routed Label Distribution Protocol DHCPv6 Dynamic Host Configuration Protocol for IPv6 DiffServ Differentiated Services FEC Forwarding Equivalent Class GMPLS Generalized MultiProtocol Label Switching HA Home Agent ICMP Internet Con
34、trol Message Protocol IP Internet Protocol IPv4 Internet Protocol version 4 IPv6 Internet Protocol version 6 IMS IP Multimedia Subsystem IntServ Integrated Services ISDN Integrated Services Digital Network LDP Label Distribution Protocol LSP Label Switched Path MN Mobile Node MPLS MultiProtocol Labe
35、l Switching NACF Network Attachment Control Function NGN Next Generation Network NNI Network-Network Interface PSTN Public Switched Telephone Network QoS Quality of Service RACF Resource and Admission Control Function Rec. ITU-T Y.2054 (02/2008) 3 RSVP Resource Reservation Protocol RSVP-TE Resource
36、Reservation Protocol-Traffic Engineering SIP Session Initiation Protocol SLA Service Level Agreement UNI User-Network-Interface VoIP Voice over IP VPN Virtual Private Network 5 Conventions This Recommendation basically assumes that IPv6-based NGN uses both existing signalling protocols and newly dev
37、eloped signalling for supporting NGN functions. Thus, this Recommendation presents guidelines on how to support the existing signalling protocols and signalling for supporting several functions required in NGN using the IPv6 features. 6 Features of signalling using IPv6 6.1 Features of the existing
38、signalling protocols There are several existing signalling protocols in Internet Protocol version 4 (IPv4) networks, providing some form of control delivery mechanism with or without quality of service (QoS) support. Like Internet control message protocol (ICMP), such kind of signalling protocol is
39、for information notification only. Similar to resource reservation protocol (RSVP), however, some signalling may transfer QoS-related information that can be used by a node to determine the control of resource of the node. Figure 1 Classification of existing signalling In analysing the features of e
40、xisting signalling mechanisms, the signalling protocols of the transport stratum and service stratum can be considered. As shown in Figure 1, the transport stratum consists of access and core domains; transport QoS signalling is used to perform bandwidth reservation, admission control, and QoS mappi
41、ng. In the service stratum, call signalling for call set-up/release 4 Rec. ITU-T Y.2054 (02/2008) and application signalling to support various services are supported. The following are the features of the existing signalling protocols: Signalling for the transport stratum: RSVP-TE (including RSVP-T
42、E extension for GMPLS) Resource reservation protocol-traffic engineering (RSVP-TE) b-IETF RFC 3209 based on RSVP b-IETF RFC 2205 is used for the integrated services (IntServ) model. Both RSVP and RSVP-TE are implemented at the Internet protocol (IP) layer. RSVP is defined to support QoS in IP networ
43、ks with fine granularity, although this leads to scalability problems. RSVP-TE has some additional concepts such as label distribution, aggregated flow, and explicit route. CR-LDP (including CR-LDP extension for GMPLS) Constraint-based routed label distribution protocol (CR-LDP) b-IETF RFC 3472 from
44、 label distribution protocol (LDP) is used for almost the same purpose as RSVP-TE. CR-LDP contains extensions to enable LDP to extend its capabilities, e.g., set up paths based on explicit route constraints, QoS constraints, and other constraints. Signalling for the service stratum: SIP and H.323 Se
45、ssion initiation protocol (SIP) and H.323 play a key role in call control for session-based services in NGN. In particular, SIP is an application-layer control protocol for creating, modifying, and terminating sessions with one or more participants. H.248 H.248 is the media gateway control protocol
46、for use in distributed switching environments. Use of this protocol enables controlling media gateways to set up media (e.g., voice traffic) paths through the distributed network. 6.2 IPv6 features to support signalling A large percentage of users in NGN will use IPv6 addresses due to the lack of IP
47、v4 addresses, etc. Emphasis is placed on these applications to use the QoS mechanism supported by the IPv6 protocol. Therefore, signalling using IPv6 for NGN is required; existing signalling protocols are concerned only with the delivery of signalling messages over IPv4 networks. From the signalling
48、 viewpoint, the IPv6 protocol has the following features related to QoS and other capabilities: Flow label Flow label enables classification of packets belonging to a specific flow and flow-specific treatment. The key advantage of flow label is that transit routers need not open the inner packet to
49、identify the flow; thus aiding in the identification of the flow when using encryption and other scenarios. Traffic class The traffic class field may be used to set specific precedence or differentiated service code point values. Extension headers The extension header can ensure both flexibility and efficiency in the creation of the IPv6 datagram. All fields required only for special purposes, e.g., QoS support, are put into extension headers and placed in the packet, when necessary. In particular, signalling
