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 H.248.89 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (10/2014) SERIES H: AUDIOVISUAL AND MULTIMEDIA SYSTEMS Infrastructure of audiovisual services Communication procedures Gateway Control Protocol: TCP support packages
2、Recommendation ITU-T H.248.89 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 Communi
3、cation procedures H.240H.259 Coding 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
4、multimedia services H.360H.369 Telepresence H.420H.429 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 Mobi
5、le multimedia collaboration applications and services 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
6、procedures H.560H.569 BROADBAND, TRIPLE-PLAY AND ADVANCED MULTIMEDIA SERVICES Broadband multimedia services over VDSL H.610H.619 Advanced multimedia services and applications H.620H.629 Ubiquitous sensor network applications and Internet of Things H.640H.649 IPTV MULTIMEDIA SERVICES AND APPLICATIONS
7、 FOR IPTV General aspects H.700H.719 IPTV terminal devices H.720H.729 IPTV middleware H.730H.739 IPTV application event 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 Digital Signage H.780H.789 E-HEAL
8、TH MULTIMEDIA SERVICES AND APPLICATIONS Interoperability compliance testing of personal health systems (HRN, PAN, LAN and WAN) H.820H.859 Multimedia e-health data exchange services H.860H.869 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T H.248.89 (10/2014) i Reco
9、mmendation ITU-T H.248.89 Gateway Control Protocol: TCP support packages Summary The transmission control protocol (TCP) is a connection-oriented IP transport protocol, which leads to specific requirements on ITU-T H.248 support for the control of bearer procedures related to the establishment and r
10、elease of TCP connections, as well as the MG internal interworking of TCP packets. Recommendation ITU-T H.248.89 provides ITU-T H.248 packages for support of TCP, complemented by models, considerations of package mode operations and signalling flows. History Edition Recommendation Approval Study Gro
11、up Unique ID* 1.0 ITU-T H.248.89 2014-10-14 16 11.1002/1000/12240 _ * To access the Recommendation, type the URL http:/handle.itu.int/ in the address field of your web browser, followed by the Recommendations unique ID. For example, http:/handle.itu.int/11.1002/1000/11830-en. ii Rec. ITU-T H.248.89
12、(10/2014) 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 responsibl
13、e 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-T
14、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 ba
15、sis 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 mandator
16、y 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 u
17、se of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTSITU 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
18、 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,
19、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 2015 All rights reserved. No p
20、art of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T H.248.89 (10/2014) iii Table of Contents Page 1 Scope . 1 1.1 Applicability statements . 1 1.2 Package-less TCP connection control 1 2 References . 2 3 Definitions 3 3.1 Terms
21、defined elsewhere 3 3.2 Terms defined in this Recommendation . 4 4 Abbreviations and acronyms 4 5 Conventions 5 5.1 Naming of stream endpoints and terminations . 5 5.2 TCP bearer 6 5.3 TCP bearer control . 6 5.4 TCP endpoint 6 6 Motivation use cases and models . 7 6.1 Bearer connection network use c
22、ases . 7 6.2 Bearer connection model 8 7 TCP basic connection control package . 10 7.1 Properties 11 7.2 Events . 13 7.3 Signals 14 7.4 Statistics 15 7.5 Error codes 15 7.6 Procedures 15 8 TCP-specific stream endpoint interlinkage procedures 19 8.1 Introduction 19 8.2 Procedures 19 9 TCP retransmiss
23、ion metrics package 21 9.1 Properties 21 9.2 Events . 21 9.3 Signals 21 9.4 Statistics 21 9.5 Error codes 22 9.6 Procedures 22 10 Package-less TCP control . 23 10.1 Package-less TCP control in other ITU-T H.248.x-Recommendations . 23 10.2 Principal ITU-T H.248 control steps for communication establi
24、shment . 24 10.3 Release of TCP connection 27 iv Rec. ITU-T H.248.89 (10/2014) Page 11 Security considerations . 27 Annex A State modelling for TCP bearer connection endpoints 28 A.1 Introduction and purpose 28 A.2 Original state model for TCP bearer connection endpoints . 28 A.3 Simplified state mo
25、del for ITU-T H.248-based TCP basic connection control . 28 A.4 State models versus TCP modes of operation 30 Appendix I Sample use-cases of TCP connection control 31 I.1 Use case #1: WebRTC to NGN/IMS interworking function with termination of transport security by MG 31 Appendix II Example call flo
26、ws . 32 II.1 Overview 32 II.2 Basic TCP bearer connection control . 32 II.3 Extended TCP bearer connection control . 36 Appendix III Illustration of the TCP basic connection control package protocol semantics . 38 III.1 Overview 38 III.2 Conventions 38 III.3 Establishment of TCP bearer connections 3
27、8 III.4 Release of TCP bearer connections 41 Appendix IV Illustration of the TCP-specific interlinkage procedures 43 IV.1 Overview 43 IV.2 Conventions 43 IV.3 Usage of stream endpoint interlinkage capability 43 IV.4 Usage of Oneway Release Indicator property 47 IV.5 Combined consideration of both pr
28、operties . 49 Appendix V Relation to similar ITU-T H.248 packages 53 V.1 Overview of TCP related packages 53 V.2 ITU-T Q.1950 . 53 V.3 ITU-T H.248.67 56 V.4 ITU-T H.248.84 56 V.5 ITU-T H.248.43 and ITU-T H.248.79 58 Bibliography. 59 Rec. ITU-T H.248.89 (10/2014) 1 Recommendation ITU-T H.248.89 Gatew
29、ay Control Protocol: TCP support packages 1 Scope In scope of this Recommendation are ITU-T H.248 IP media gateway TCP-based bearer interfaces. Such an ITU-T H.248 MG provides various functions for processing of TCP/IP packets, TCP payload data and is involved in functions related to TCP protocol co
30、ntrol information (based on TCP header flags). This Recommendation focuses primarily on the aspect of TCP connection control, which comprises the establishment and release of TCP bearer connections. The Recommendation considers: connection models with a single or multiple TCP bearer connection endpo
31、ints within an ITU-T H.248 context; establishment, through-connection and release behaviour in case of end-to-end TCP bearer connections across two ITU-T H.248 TCP terminations (“a so-called ITU-T H.248 TCP media stream“); different ITU-T H.248 control models. Further, this Recommendation provides i
32、nformation on existing ITU-T H.248 tools with respect to other TCP support functions. 1.1 Applicability statements Table 1 summarizes all possible TCP-based interfaces of ITU-T H.248 entities (under the assumption of an underlying IP network) and their relevance for this Recommendation. Table 1 Prin
33、cipal TCP-based interfaces of ITU-T H.248 entities and their relevance for this Recommendation TCP-based transport ITU-T H.248 entity Relevance Call control interface (e.g., SIP) MGC Out of scope of this Recommendation. Gateway control interface (ITU-T H.248) MGC, MG Out of scope of this Recommendat
34、ion. Possible ITU-T H.248 transport modes are indicated by ITU-T H.248.67. Usage of a TCP-based ITU-T H.248 transport mode would be typically specified by an ITU-T H.248 profile (as part of clause 6.12 in the profile definition template (see Appendix III in ITU-T H.248.1). Bearer interface MG Within
35、 the scope of this Recommendation. 1.2 Package-less TCP connection control Figure 1 summarizes the methods for ITU-T H.248-based TCP connection control (at the MG bearer interface). The required approach for TCP connection control concerning the TCP proxy mode and TCP to non-TCP interworking is base
36、d on package-defined ITU-T H.248 elements introduced by this Recommendation. However, the package-less option should be used in the stateless TCP interworking configurations TCP relay and TCP merge mode (see clause 10.1). Furthermore, the package-less option is required for transparent forwarding of
37、 TCP traffic. TCP transparent forwarding covers both TCP protocol control information (“the TCP header“) and TCP payload data, and is typically 2 Rec. ITU-T H.248.89 (10/2014) characteristic of the application-agnostic TCP relay mode and application-agnostic TCP merge mode (after TCP connection esta
38、blishment). Figure 1 Overview: Methods for ITU-T H.248-based TCP connection control The usage of some SDP elements is appropriate in package-based TCP connection control, as long as their semantics do not contradict the ITU-T H.248 elements. The bearer type indication TCP is always required (see cla
39、use 10.2.3). The SDP “a=setup“ attribute is also used in the package-based approach. 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
40、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 Recommendations and other references listed below. A list of the currently valid ITU
41、-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 H.248.1 Recommendation ITU-T H.248.1 (2013), Gateway control protocol: Version 3. ITU-T H.248.37 Recommendation ITU-T H
42、.248.37 (2008), Gateway control protocol: IP NAPT traversal package. ITU-T H.248.40 Recommendation ITU-T H.248.40 (2013), Gateway control protocol: Application data inactivity detection package. ITU-T H.248.43 Recommendation ITU-T H.248.43 (2008), Gateway control protocol: Packages for gate manageme
43、nt and gate control. ITU-T H.248.50 Recommendation ITU-T H.248.50 (2010), Gateway control protocol: NAT traversal toolkit packages. ITU-T H.248.53 Recommendation ITU-T H.248.53 (2009), Gateway control protocol: Traffic management packages. ITU-T H.248.64 Recommendation ITU-T H.248.64 (2013), Gateway
44、 control protocol: IP router packages. ITU-T H.248.67 Recommendation ITU-T H.248.67 (2009), Gateway control protocol: Transport mode indication package. Rec. ITU-T H.248.89 (10/2014) 3 ITU-T H.248.69 Recommendation ITU-T H.248.69 (2009), Gateway control protocol: Packages for interworking between MS
45、RP and H.248. ITU-T H.248.78 Recommendation ITU-T H.248.78 (2013), Gateway control protocol: Bearer-level application level gateway. ITU-T H.248.79 Recommendation ITU-T H.248.79 (2012), Gateway control protocol: Guidelines for packet-based streams. ITU-T H.248.84 Recommendation ITU-T H.248.84 (2012)
46、, Gateway control protocol: NAT-traversal for peer-to-peer services. ITU-T H.248.88 Recommendation ITU-T H.248.88 (2014), Gateway control protocol: RTP topology dependent RTCP handling by ITU-T H.248 media gateways with IP terminations. ITU-T H.248.90 Recommendation ITU-T H.248.90 (2014), Gateway co
47、ntrol protocol: ITU-T H.248 packages for control of transport security using transport layer security (TLS). ITU-T H.248.92 Recommendation ITU-T H.248.92 (2014), Gateway control protocol: Stream endpoint interlinkage package. ITU-T Q.1950 Recommendation ITU-T Q.1950 (2002), Bearer independent call b
48、earer control protocol. ITU-T X.200 Recommendation ITU-T X.200 (1994) | ISO/IEC 7498-1: 1994, Information technology - Open Systems Interconnection - Basic Reference Model: The basic model. IETF RFC 793 IETF RFC 793 (1981), Transmission Control Protocol. IETF RFC 1191 IETF RFC 1191 (1990), Path MTU
49、Discovery. IETF RFC 1981 IETF RFC 1981 (1996), Path MTU Discovery for IP version 6. IETF RFC 4022 IETF RFC 4022 (2005), Management Information Base for the Transmission Control Protocol (TCP). IETF RFC 4145 IETF RFC 4145 (2005), TCP-Based Media Transport in the Session Description Protocol (SDP). IETF RFC 4898 IETF RFC 4898 (2007), TCP Extended Statistics MIB. IETF RFC 4976 IETF RFC 4976 (2007), Relay Extensions fo
