1、 International Telecommunication Union ITU-T H.248.67TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (12/2009) SERIES H: AUDIOVISUAL AND MULTIMEDIA SYSTEMSInfrastructure of audiovisual services Communication procedures Gateway control protocol: Transport mode indication package Recommendation ITU-T
2、H.248.67 ITU-T H-SERIES RECOMMENDATIONS AUDIOVISUAL AND MULTIMEDIA SYSTEMS CHARACTERISTICS OF VISUAL TELEPHONE SYSTEMS H.100H.199 INFRASTRUCTURE OF AUDIOVISUAL SERVICES General H.200H.219 Transmission multiplexing and synchronization H.220H.229 Systems aspects H.230H.239 Communication procedures H.2
3、40H.259Coding of moving video H.260H.279 Related systems aspects H.280H.299 Systems and terminal equipment for audiovisual services H.300H.349 Directory services architecture for audiovisual and multimedia services H.350H.359 Quality of service architecture for audiovisual and multimedia services H.
4、360H.369 Supplementary services for multimedia H.450H.499 MOBILITY AND COLLABORATION PROCEDURES Overview of Mobility and Collaboration, definitions, protocols and procedures H.500H.509 Mobility for H-Series multimedia systems and services H.510H.519 Mobile multimedia collaboration applications and s
5、ervices H.520H.529 Security for mobile multimedia systems and services H.530H.539 Security for mobile multimedia collaboration applications and services H.540H.549 Mobility interworking procedures H.550H.559 Mobile multimedia collaboration inter-working procedures H.560H.569 BROADBAND, TRIPLE-PLAY A
6、ND ADVANCED MULTIMEDIA SERVICES Broadband multimedia services over VDSL H.610H.619 Advanced multimedia services and applications H.620H.629 IPTV MULTIMEDIA SERVICES AND APPLICATIONS FOR IPTV General aspects H.700H.719 IPTV terminal devices H.720H.729 IPTV middleware H.730H.739 IPTV application event
7、 handling H.740H.749 IPTV metadata H.750H.759 IPTV multimedia application frameworks H.760H.769 IPTV service discovery up to consumption H.770H.779 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T H.248.67 (12/2009) i Recommendation ITU-T H.248.67 Gateway control pr
8、otocol: Transport mode indication package Summary Gateway control signalling traffic is carried over a transport connection between the media gateway controller (MGC) and media gateway (MG). Recommendation ITU-T H.248 supports multiple, different transport technologies. Each possible protocol stack
9、variant is called ITU-T H.248 transport mode. Recommendation ITU-T H.248.67 contains an ITU-T H.248 package to determine the supported transport modes by a MG and the indication of a preferred mode. The package enables an MGC to audit and change the transport mode. Transport mode changes may be driv
10、en by network evolution, i.e., transitioning from IP version 4 to IP version 6 environments. The added value of this package is given by the capability to support online transport mode changes. History Edition Recommendation Approval Study Group 1.0 ITU-T H.248.67 2009-12-14 16 ii Rec. ITU-T H.248.6
11、7 (12/2009) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsi
12、ble 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 Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-
13、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 which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative
14、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 this Recommendation is voluntary. However, the Recommendation may contain certain mandat
15、ory 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 language such as “must“ and the negative equivalents are used to express requirements. The
16、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 Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes
17、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 approval of this Recommendation, ITU had not received notice of intellectual property
18、, 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 patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2010 All rights reserved. No
19、 part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T H.248.67 (12/2009) iii CONTENTS Page 1 Scope 1 1.1 Examples for typical transport mode changes 1 1.2 Applicability . 2 2 References. 4 3 Definitions 5 3.1 Terms defined elsew
20、here 5 3.2 Terms defined in this Recommendation . 5 4 Abbreviations and acronyms 5 5 Conventions 6 6 Gateway control protocol transport mode indication package . 6 6.1 Properties 6 6.2 Events . 7 6.3 Signals 8 6.4 Statistics 8 6.5 Error codes 8 6.6 Procedures 8 Bibliography. 12 Rec. ITU-T H.248.67 (
21、12/2009) 1 Recommendation ITU-T H.248.67 Gateway control protocol: Transport mode indication package 1 Scope ITU-T H.248 is a “transport technology independent“ or “bearer-independent“ signalling protocol. This means it may be carried over multiple, different transport technologies. There is no tigh
22、t coupling to a single, specific underlying protocol stack. Such a protocol design satisfies multiple protocol engineering requirements like: a) the signalling protocol is independent of network infrastructure, b) the signalling protocol may be used in present network infrastructures that are very h
23、eterogeneous concerning deployed bearer technologies, and c) the signalling protocol can be used in network infrastructures that evolve over time. The choice of a particular transport technology, either due to an initial negotiation process or due to a later change procedure, may benefit from corres
24、pondent signalling elements. This Recommendation provides functionality for the indication and negotiation of an ITU-T H.248 transport mode (see clause 3.1.1). 1.1 Examples for typical transport mode changes The transport mode is tightly coupled to the concept of the ITU-T H.248 control association
25、(CA). A static, never changing transport mode may be considered as a priori knowledge, i.e., a provisioning subject. There would be then configuration management actions, on the MG and MGC sides, before any registration attempt would be issued by the MG. This might be sufficient for some use cases,
26、but the lack of flexibility has shortcomings in regard to evolving networks, multi-transport mode capable ITU-T H.248 entities and/or high service availability requirements. The transport mode may be characterized by two protocol stack segments (see also definition in clause 3.1.1): “network and low
27、er layers“ and “transport and higher layers“, represented in the x- and y-axis in Figure 1. Figure 1 shows some typical transport mode changes: 1) ATM network replacement by IP infrastructure: e.g., from “MTP-3b/AAL5/ATM“ to “SCTP/IPv4“. 2) Introduction of IP version 6 in an IPv4 infrastructure: e.g
28、., from “UDP/IPv4“ to “UDP/IPv6“. 3) Replacement of an inappropriate transport technology by an optimized protocol for signalling transport: e.g., from “TCP/IPv4“ to “SCTP/IPv4“. 4) Combination of 2) and 3) in one step: e.g., from “UDP/IPv4“ to “SCTP/IPv6“. 2 Rec. ITU-T H.248.67 (12/2009) “Network l
29、ayer“ H.248.67(09)_F01 AAL5/ATM IPv4 MTP3b/N-SAAL SSCOP ALF IPv6 M3UA/SCTPNativeSCTP UDP TCP “Transport layer“, framingTransport mode for ITU-T H.248 protocol data units (“signalling transport“) Transport mode changes examples Examples: No. From To 1) MTP-3b/AAL5/ATM SCTP/IPv42) UDP/IPv4 UDP/IPv6 3)
30、 TCP/IPv4 SCTP/IPv44) UDP/IPv4 SCTP/IPv61 342Figure 1 Example typical transport mode changes for ITU-T H.248 control associations 1.2 Applicability 1.2.1 Online versus offline transport mode changes It may be noted that any transport mode change does not necessarily require the application of the (S
31、erviceChange based) procedures defined by this Recommendation. Transport mode changes could be completely “controlled“ by management plane activities, i.e., via configuration management. Such a procedure implies the transition of all involved ITU-T H.248 entities (MGC and associated MG(s) in a parti
32、cular management state in order to execute the configuration changes. Such a management state correlates with an “Out-of-Service“ phase, the ITU-T H.248 entities are therefore entirely “offline“. The ITU-T H.248 control association does not exist anymore during the “provisioned“ transport mode chang
33、e. In order to minimize such network “Out-of-Service“ periods, it may be beneficial for ServiceChange based (termed “online“ here) transport mode change support. The coordination and synchronization of transport mode changes via such ITU-T H.248 “call-independent“ procedures might be a further advan
34、tage of the application of the trm package. 1.2.2 Supported attributes of transport mode Figure 2 summarizes the IPv4 based transport modes. The usage of an encryption protocol for ITU-T H.248 traffic may be considered as third dimension of the transport mode. Figure 3 illustrates possible transport
35、 modes with encryption on network (L3) or transport (L4) protocol layer (see also IETF RFC 3788). Rec. ITU-T H.248.67 (12/2009) 3 L2L1H.248IPv4UDPL2L1H.248IPv4TCPL2L1H.248IPv4SCTPL2L1H.248IPv4M3UA/SCTP1.1) IPv4 (unsecured)Figure 2 Overview of major transport modes with IP version 4 and without encry
36、ption protocol L2L1H.248IPv4UDPL2L1H.248IPv4TCPL2L1H.248IPv4SCTPL2L1H.248IPv4M3UA/SCTP1.2) IPv4 (L3 secured)IPsec IPsec IPsec IPsecL2L1H.248IPv4UDPL2L1H.248IPv4TCPL2L1H.248IPv4SCTPL2L1H.248IPv4SCTP1.3) IPv4 (L4 secured)DTLS TLS TLSTLSM3UAFigure 3 Overview of major transport modes with IP version 4 a
37、nd security support on network or transport layer Figure 4 provides an overview of major transport modes with IP version 6 as network layer protocol. Figure 5 provides an overview of major transport modes for ATM networks. 4 Rec. ITU-T H.248.67 (12/2009) L2L1H.248IPv6UDPL2L1H.248IPv6TCPL2L1H.248IPv6
38、SCTPL2L1H.248IPv6M3UA/SCTP2.1) IPv6 (unsecured)L2L1H.248IPv6UDPL2L1H.248IPv6TCPL2L1H.248IPv6SCTPL2L1H.248IPv6M3UA/SCTP2.2) IPv6 (L3 secured)IPsec IPsec IPsec IPsec2.3) IPv6 (L4 secured)L2L1H.248IPv6UDPL2L1H.248IPv6TCPL2L1H.248IPv6SCTPL2L1H.248IPv6DTLS TLS TLSSCTPTLSM3UAFigure 4 Overview of major tra
39、nsport modes with IP version 6 (unsecured and secured transport) L1H.248AAL5/ATMMTP3b/N-SAALL1H.248SSCOPAAL5/ATML1H.248ALFAAL5/ATM3.1) AAL5/ATM (unsecured)Figure 5 Overview of major transport modes for ATM networks 2 References The following ITU-T Recommendations and other references contain provisi
40、ons 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 references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibili
41、ty 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 to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendat
42、ion. ITU-T H.248.1 Recommendation ITU-T H.248.1 (2005), Gateway Control Protocol: Version 3, plus Amendment 2 (2009), New Appendix IV, plus corrections and clarifications. ITU-T H.248.4 Recommendation ITU-T H.248.4 (2009), Gateway control protocol: Transport over Stream Control Transmission Protocol
43、 (SCTP). ITU-T H.248.5 Recommendation ITU-T H.248.5 (2009), Gateway control protocol: Transport over ATM. Rec. ITU-T H.248.67 (12/2009) 5 ETSI TS 129 202 ETSI TS 129 202 (2009), Universal Mobile Telecommunications System (UMTS); Signalling System No. 7 (SS7) signalling transport in core network; Sta
44、ge 3 (3GPP TS 29.202 version 8.1.1 Release 8). IETF RFC 3788 IETF RFC 3788 (2004), Security Considerations for Signaling Transport (SIGTRAN) Protocols. IETF RFC 4301 IETF RFC 4301 (2005), Security Architecture for the Internet Protocol. IETF RFC 4347 IETF RFC 4347 (2006), Datagram Transport Layer Se
45、curity. IETF RFC 5246 IETF RFC 5246 (2008), The Transport Layer Security (TLS) Protocol Version 1.2. 3 Definitions 3.1 Terms defined elsewhere None. 3.2 Terms defined in this Recommendation 3.2.1 transport mode: The actual protocol stack below the ITU-T H.248 protocol layer. This protocol stack may
46、be divided into two main portions: a) transport protocol (L4) and higher layers, and b) network protocol (L3) and lower layers. Any transport mode may also provide encryption on network (L3) or transport (L4) protocol layer. NOTE See also clauses 5.3.1, 10 and 11 of b-ITU-T H.Sup7 concerning IP-base
47、d transport connections. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations: AAL5 ATM Adaptation Layer type 5 ALF Application Level Framing ATM Asynchronous Transfer Mode CA (H.248) Control Association DTLS Datagram Transport Layer Security IP Internet Protocol IPsec I
48、P security IPv4 IP version 4 IPv6 IP version 6 L1 (Protocol) Layer 1 L2 (Protocol) Layer 2 M3UA Signalling System No. 7 (SS7) Message Transfer Part 3 (MTP3) User Adaptation Layer MG Media Gateway MGC Media Gateway Controller mID (H.248) Message Identifier MTP-3b Message Transfer Part level 3 using I
49、TU-T Q.2140 6 Rec. ITU-T H.248.67 (12/2009) NNI Network-to-Network Interface N-SAAL NNI Signalling ATM Adaptation Layer SCTP Stream Control Transmission Protocol SSCOP Service Specific Connection-Oriented Protocol UDP User Datagram Protocol TCP Transmission Control Protocol TLS Transport Layer Security 5 Conventions None. 6 Gateway control protocol transport mode indication package Package name: Gateway Control Protocol Transport Mode Indication Package Package ID: trm (0x00d3) Description: This package all
