1、 International Telecommunication Union ITU-T J.178TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (11/2005) SERIES J: CABLE NETWORKS AND TRANSMISSION OF TELEVISION, SOUND PROGRAMME AND OTHER MULTIMEDIA SIGNALS IPCablecom IPCablecom CMS to CMS signalling Recommendation ITU-T J.178 Rec. ITU-T J.178 (1
2、1/2005) i Recommendation ITU-T J.178 IPCablecom CMS to CMS signalling Summary Recommendation ITU-T J.178 describes the IPCablecom Call Management Server (CMS) to CMS Signalling protocol intended for use by a CMS to communicate with another CMS in order to support packet-based voice and other real-ti
3、me multimedia applications. The protocol exchanges between a CMS and a Media Gateway Controller (MGC) are identical to those between CMSs, and so for purposes of this Recommendation the MGC is considered identical to a CMS. Source Recommendation ITU-T J.178 was approved on 29 November 2005 by ITU-T
4、Study Group 9 (2005-2008) under Recommendation ITU-T A.8 procedures. ii Rec. ITU-T J.178 (11/2005) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecomm
5、unication 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 worldwide basis. The World Telecommunication Standardization Asse
6、mbly (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 in WTSA Resolution 1. In some areas of information technology whi
7、ch 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 administration and a recognized operating agency. Compliance with t
8、his 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 provisions are met. The words “shall“ or some other obligatory langu
9、age 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 attention to the possibility that the practice or implementation of this R
10、ecommendation 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 Recommendation development process. As of the date of
11、 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 represent the latest information and are therefore strongly urged to consult the TSB
12、 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 J.178 (11/2005) iii CONTENTS Page 1 Scope 1 2 References. 1 2.1 Normative references 1 2.2 R
13、eference acquisition . 3 3 Terms and definitions . 3 4 Abbreviations, acronyms and conventions. 4 4.1 Abbreviations and acronyms 4 4.2 Conventions 5 5 Background and motivation 5 5.1 Requirements and design principles. 6 5.2 IPCablecom architecture 7 5.3 CMSS trust model 9 5.4 CMS to CMS architectur
14、al model 10 5.5 Overview of CMS behaviour 12 5.6 Basic telephony call flow . 13 5.7 CMS-MGC basic telephony call flow 15 6 SIP profile. 18 6.1 Introduction 18 6.2 Overview of SIP functionality 18 6.3 Terminology . 18 6.4 Overview of operation 18 6.5 Structure of the protocol. 18 6.6 Definitions 18 6
15、.7 SIP messages 18 6.8 General user agent behaviour . 19 6.9 Cancelling a request . 21 6.10 Registrations. 21 6.11 Querying for capabilities 21 6.12 Dialogs 21 6.13 Initiating a session 21 6.14 Modifying an existing session 21 6.15 Terminating a session. 22 6.16 Proxy behaviour 22 6.17 Transactions
16、22 6.18 Transport. 22 6.19 Common message components 22 6.20 Header fields. 22 6.21 Response codes. 29 iv Rec. ITU-T J.178 (11/2005) Page 6.22 Usage of HTTP authentication . 29 6.23 S/MIME 29 6.24 Examples 29 6.25 Augmented BNF for the SIP protocol 29 6.26 Security considerations: Threat model and s
17、ecurity usage recommendations 29 6.27 Table of timer values 29 7 SIP extensions. 30 7.1 URIs for telephone calls . 31 7.2 Reliability of provisional responses . 33 7.3 SIP UPDATE method. 33 7.4 Integration of resource management and SIP. 33 7.5 SIP-specific event notification . 34 7.6 The REFER Meth
18、od. 34 7.7 SIP Proxy to Proxy Extensions for Supporting DCS . 35 7.8 The SIP “Replaces“ header. 42 7.9 Private extensions to the SIP protocol for asserted identity within trusted networks . 42 7.10 A message summary and message waiting indication event package for the Session Initiation Protocol (SI
19、P) 43 8 CMS-CMS Signalling. 47 8.1 CMS interfaces . 47 8.2 CMS retransmission, reliability, and recovery strategies. 54 8.3 CMS to CMS routing 55 8.4 CMS procedures . 56 9 Application-layer anonymizer 121 9.1 Signalling Content Privacy. 122 9.2 IP address Privacy 123 Appendix I Timer summary 125 App
20、endix II CMSS message and header overview. 126 Appendix III Acknowledgments. 130 Bibliography. 131 Rec. ITU-T J.178 (11/2005) 1 Recommendation ITU-T J.178 IPCablecom CMS to CMS signalling 1 Scope This Recommendation describes the IPCablecom Call Management Server (CMS) to CMS signalling protocol int
21、ended for use by a CMS to communicate with another CMS in order to support packet-based voice and other real-time multimedia applications. The protocol exchanges between a CMS and a Media Gateway Controller (MGC) are identical to those between CMSs, and so for purposes of this Recommendation the MGC
22、 is considered identical to a CMS. CMSs currently support multimedia endpoints (within the IPCablecom infrastructure) that use the Network-based Call Signalling (ITU-T Rec. J.162) (NCS) protocol and the PSTN Gateway Call Signalling Protocol (ITU-T Rec. J.171.x) (TGCP) for communicating signalling in
23、formation between the endpoint and the CMS. In the future, other protocols may be supported as well, and the CMS to CMS protocol is intended to be sufficiently general to accommodate such protocols without change. The CMS to CMS protocol uses the Session Initiation Protocol 2.0 (SIP) specification w
24、ith extensions and usage rules that support commonly available local and CLASSSMservices. This protocol is referred to as the Call Management Server Signalling (CMSS) protocol. The CMSS protocol takes into account the need to manage access to network resources and account for resource usage. The usa
25、ge rules defined in this Recommendation specifically address the coordination between CMS signalling and IPCablecom Dynamic Quality of Service (QoS) mechanisms for managing resources over the cable access network. In addition, this Recommendation defines the protocols and messages needed between Cal
26、l Management Servers for supporting these services. This Recommendation specifies the protocols and procedures to use between CMSs belonging to a single service provider as well as between CMSs that belong to different service providers. In the case that the CMSs are owned by multiple service provid
27、ers, it is assumed that the service providers have a mutual trust relationship. Other IPCablecom Recommendations describe interfaces between other system elements. These Recommendations cover areas such as: Event Message recording for billing and other back office functions (ITU-T Rec. J.164); Dynam
28、ic Quality of Service (ITU-T Rec. J.163); Operations and Provisioning (ITU-T Rec. J.167); and Security (ITU-T Rec. J.170). These other specifications indirectly place requirements on the signalling protocol to ensure that it transports the correct data needed to implement a complete system. This Rec
29、ommendation includes syntax and protocols for implementing these requirements. Currently, this Recommendation does not address interworking with non-IPCablecom-compliant devices. NOTE Where this Recommendation discusses interworking with the PSTN, this is done purely to illustrate the behaviour of t
30、he CMS and MGC in the context of off-net originated or terminated calls. The primary purpose of this Recommendation is to describe CMSS signalling. A full specification of interworking with the PSTN is not provided by this Recommendation. Other Recommendations (such as ITU-T Rec. Q.1912.5 or IETF RF
31、C 3398) describe detailed interworking between SIP and ISUP. 2 References 2.1 Normative 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
32、 indicated were valid. All Recommendations and other references are subject to revision; 2 Rec. ITU-T J.178 (11/2005) 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 l
33、ist 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. Recommendation ITU-T E.123 (2001), Notation for national and international telephone numbers, e
34、-mail addresses and Web addresses. Recommendation ITU-T E.164 (2005), The international public telecommunication numbering plan. Recommendation ITU-T J.160 (2002), Architectural framework for the delivery of time-critical services over cable television networks using cable modems. Recommendation ITU
35、-T J.162 (2005), Network call signalling protocol for the delivery of time-critical services over cable television networks using cable modems. Recommendation ITU-T J.163 (2005), Dynamic quality of service for the provision of real-time services over cable television networks using cable modems. Rec
36、ommendation ITU-T J.164 (2005), Event message requirements for the support of real-time services over cable television networks using cable modems. Recommendation ITU-T J.170 (2005), IPCablecom security specification. Recommendation ITU-T J.171.0 (2005), IPCablecom trunking gateway control protocol
37、(TGCP): Profiles overview. Recommendation ITU-T J.171.1 (2005), IPCablecom trunking gateway control protocol (TGCP): Profile 1. Recommendation ITU-T J.171.2 (2005), IPCablecom trunking gateway control protocol (TGCP): Profile 2. IETF RFC 2234 (1997), Augmented BNF for Syntax Specifications: ABNF. IE
38、TF RFC 2396 (1998), Uniform Resource Identifiers (URI): Generic Syntax. IETF RFC 3261 (2002), SIP: Session Initiation Protocol. IETF RFC 3262 (2002), Reliability of Provisional Responses in the Session Initiation Protocol (SIP). IETF RFC 3263 (2002), Session Initiation Protocol (SIP): Locating SIP S
39、ervers. IETF RFC 3265 (2002), Session Initiation Protocol (SIP) Specific Event Notification. IETF RFC 3311 (2002), The Session Initiation Protocol (SIP) UPDATE Method. IETF RFC 3312 (2002), Integration of Resource Management and Session Initiation Protocol (SIP). IETF RFC 3323 (2002), A Privacy Mech
40、anism for the Session Initiation Protocol (SIP). IETF RFC 3325 (2002), Private Extensions to the Session Initiation Protocol (SIP) for Asserted Identity within Trusted Networks. IETF RFC 3515 (2003), The Session Initiation Protocol (SIP) Refer Method. IETF RFC 3603 (2003), Private Session Initiation
41、 Protocol (SIP) Proxy-to-Proxy Extensions for Supporting the PacketCable Distributed Call Signalling Architecture. IETF RFC 3842 (2004), A Message Summary and Message Waiting Indication Event Package for the Session Initiation Protocol (SIP). IETF RFC 3891 (2004), The Session Initiation Protocol (SI
42、P) Replaces Header. Rec. ITU-T J.178 (11/2005) 3 IETF RFC 3966 (2004), The tel URI for Telephone Numbers. IETF RFC 4694 (2006), Number Portability Parameters for the “tel“ URI. 2.2 Reference acquisition ITU-T Recommendations available at: http:/www.itu.int/ITU-T IETF RFCs available at: http:/www.iet
43、f.org/rfc SCTE Standards available at: http:/www.scte.org 3 Terms and definitions This Recommendation defines the following terms: 3.1 active: A service flow is said to be “active“ when it is permitted to forward data packets. A service flow must first be admitted before it is active. 3.2 admitted:
44、A service flow is said to be “admitted“ when the CMTS has reserved resources (e.g., bandwidth) for it on the DOCSIS network. 3.3 announcement server: An announcement server plays informational announcements in the IPCablecom network. Announcements are needed for communications that do not complete a
45、nd to provide enhanced information services to the user. 3.4 authentication: The process of verifying the claimed identity of an entity to another entity. 3.5 authorization: The act of giving access to a service or device if one has the permission to have the access. 3.6 domain: Any number of IPCabl
46、ecom networks controlled by a single cable network operator. 3.7 encryption: A method used to translate information in plaintext into ciphertext. 3.8 encryption key: The key used in a cryptographic algorithm to translate the plaintext to ciphertext. 3.9 endpoint: A Terminal, Gateway or MCU. 3.10 eve
47、nt message: Message capturing a single portion of a connection. 3.11 gateway: Devices bridging between the IPCablecom IP Voice Communication world and the PSTN. Examples are the Media Gateway which provides the bearer circuit interfaces to the PSTN and transcodes the media stream, and the Signalling
48、 Gateway which sends and receives circuit switched network signalling to the edge of the IPCablecom network. 3.12 header: Protocol control information located at the beginning of a protocol data unit. 3.13 key: A mathematical value input into the selected cryptographic algorithm. 3.14 network layer:
49、 Layer 3 in the Open System Interconnection (OSI) architecture that provides network information that is independent from the lower layers. 3.15 off-net call: A communication connecting an IPCablecom subscriber out to a user on the PSTN. 3.16 on-net call: A communication placed by one customer to another customer entirely on the IPCablecom Network. 3.17 privacy: A way to ensure that information is not disclosed to any one other than the intended parties. Information is usually encrypted to provide confidentiality. Also
