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 H TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Supplement 14 (10/2015) SERIES H: AUDIOVISUAL AND MULTIMEDIA SYSTEMS Gateway control protocol: SDP codepoints for gateway control Release 2 ITU-T H-series Recommendat
2、ions Supplement 14 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 proc
3、edures 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 multimedia
4、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 Mobile multimed
5、ia 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 procedures
6、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 FOR IPTV G
7、eneral 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-HEALTH MULTIMED
8、IA SERVICES AND APPLICATIONS Interoperability compliance testing of personal health systems (HRN, PAN, LAN, TAN 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. H series Supplement 14 (10/2015) i Supplem
9、ent 14 to ITU-T H-series Recommendations Gateway control protocol: SDP codepoints for gateway control Release 2 Summary Gateway control protocols may require additional session description protocol (SDP) codepoints for specific interworking functions supported at bearer plane level beyond, for examp
10、le, the SDP information used by call control protocols. Supplement 14 to ITU-T H-series Recommendations summarizes SDP codepoints that have been identified in the time-frame from June 2000 to the date of approval of this Supplement. It identifies SDP codepoints that meet ITU-T H.248.x sub-series req
11、uirements for gateway control protocols and that are available for general use by the wider standards community. Release 1 of this supplement covers: SDP codepoints for the ITU-T H.248 based control of transport layer security (TLS) and datagram transport layer security (DTLS) traffic in ITU-T H.248
12、 media gateways; preliminary SDP codepoint information for stream control transmission protocol (SCTP) traffic ITU-T H.248.97. Release 2 adds: information about the Internet Assigned Numbers Authority (IANA) registration process; fixes SDP codepoint information as required for ITU-T H.248.97. This s
13、upplement is used as a codepoint repository for the Internet Engineering Task Force (IETF) driven registration process of SDP codepoints with the IANA. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T H Suppl. 14 2014-07-11 16 11.1002/1000/12309 2.0 ITU-T H Suppl. 14 2015-10-
14、23 16 11.1002/1000/12685 _ * 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 H series Supplement 14 (10/2015) FOREWORD The International T
15、elecommunication 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 responsible for studying technical, operating an
16、d 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 study groups which, in turn, produce R
17、ecommendations 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 basis with ISO and IEC. NOTE In this pub
18、lication, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this publication is voluntary. However, the publication may contain certain mandatory provisions (to ensure, e.g., interoperability
19、 or applicability) and compliance with the publication 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 use of such words does not suggest that compliance
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21、lity of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the publication 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
22、publication. 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 2016 All rights reserved. No part of this publication may be reproduced, by any means whatsoeve
23、r, without the prior written permission of ITU. H series Supplement 14 (10/2015) iii Table of Contents Page 1 Scope . 1 2 References . 1 3 Definitions 2 3.1 Terms defined elsewhere 2 3.2 Terms defined in this Supplement 2 4 Abbreviations and acronyms 2 5 Conventions 2 6 Registration process 2 6.1 Pr
24、ocess for ITU-T H.248-specific SDP registrations . 2 6.2 Background information on IANA registration process 4 7 SDP codepoints for IANA registration . 4 7.1 SDP codepoints related to wildcarding 4 7.2 SDP codepoints related to SDP “m=“ line element 4 7.3 SDP codepoints related to SDP “a=“ lines . 5
25、 H series Supplement 14 (10/2015) 1 Supplement 14 to ITU-T H-series Recommendations Gateway control protocol: SDP codepoints for gateway control Release 2 1 Scope Gateway control protocols such as ITU-T H.248.1 may require additional session description protocol (SDP) codepoints for specific interwo
26、rking functions supported at bearer plane level, beyond, for example, the SDP information used by call control protocols. Supplement 14 to ITU-T H-series Recommendations ITU-T H.248.x summarizes SDP codepoints that have been identified in the time-frame from June 2000 to the date of approval of this
27、 Supplement. It identifies SDP codepoints that meet the ITU-T H.248.x sub-series requirements for gateway control protocols and that are available for general use by the wider standards community. Release 1 of this Supplement covers: SDP codepoints for the ITU-T H.248 based control of transport laye
28、r security (TLS) traffic ITU-T H.248.90 and datagram transport layer security (DTLS) traffic ITU-T H.248.93 in ITU-T H.248 media gateways; and preliminary SDP codepoint information for stream control transmission protocol (SCTP) traffic ITU-T H.248.97. Release 2 adds: information about the Internet
29、Assigned Numbers Authority (IANA) registration process; fixes SDP codepoint information as required for ITU-T H.248.97. This Supplement is used as a codepoint repository for the Internet Engineering Task Force (IETF) driven registration process of SDP codepoints with IANA. 2 References ITU-T H.248.x
30、 ITU-T H.248.x-series of Recommendations, Gateway control protocol. ITU-T H.248.1 Recommendation ITU-T H.248.1 (2013), Gateway control protocol: Version 3. ITU-T H.248.15 Recommendation ITU-T H.248.15 (2013), Gateway control protocol: SDP ITU-T H.248 package attribute. ITU-T H.248.39 Recommendation
31、ITU-T H.248.39 (2014), Gateway control protocol: ITU-T H.248 SDP parameter identification and wildcarding. ITU-T H.248.90 Recommendation ITU-T H.248.90 (2014), Gateway control protocol: ITU-T H.248 packages for control of transport security using transport layer security (TLS). ITU-T H.248.93 Recomm
32、endation ITU-T H.248.93 (2014), Gateway control protocol: ITU-T H.248 packages for control of transport security using the datagram transport layer security (DTLS) protocol. ITU-T H.248.97 Recommendation ITU-T H.248.97 (2015), Gateway Control Protocol: H.248 support for control of SCTP bearer connec
33、tions. IETF RFC 4566 IETF RFC 4566 (2006), SDP: Session Description Protocol. IETF RFC 4572 IETF RFC 4572 (2006), Connection-Oriented Media Transport over the Transport Layer Security (TLS) Protocol in the Session Description Protocol (SDP). 2 H series Supplement 14 (10/2015) IETF IANA REG IETF draf
34、t-leiba-cotton-iana-5226bis (2015), Guidelines for Writing an IANA Considerations Section in RFCs. IETF IANA SDP IETF draft-schwarz-mmusic-for-gw (2015), SDP codepoints for gateway control. IETF SCTP SDP IETF draft-ietf-mmusic-sctp-sdp (2015), Stream Control Transmission Protocol (SCTP)-Based Media
35、Transport in the Session Description Protocol (SDP). 3 Definitions 3.1 Terms defined elsewhere None. 3.2 Terms defined in this Supplement This Supplement defines the following term: 3.2.1 codepoint: The combination of a “signalling parameter“ plus assigned “value“ in protocol engineering. The “value
36、“ represents a codepoint (or code position) in the code space. 4 Abbreviations and acronyms This Supplement uses the following abbreviations and acronyms: DTLS Datagram Transport Layer Security SCTP Stream Control Transmission Protocol SDP Session Description Protocol TLS Transport Layer Security 5
37、Conventions None. 6 Registration process 6.1 Process for ITU-T H.248-specific SDP registrations Fundamentally, IANA registrations should be based on IETF Standards Track RFCs, particularly in the case of technologies owned by the IETF, such as SDP. The ITU-T could, but should not, bypass the IETF in
38、 the case of SDP-related registrations with IANA. The ultimate goal of unambiguous protocol semantics implies a single instance, which reviews and coordinates registration requests with IANA. Figure 1 summarizes the principles of the process followed by ITU-T Study Group 16 with respect to IANA regi
39、stration requests originated by the ITU-T H.248 protocol: H series Supplement 14 (10/2015) 3 Figure 1 IANA SDP registry Process for ITU-T H.248-specific SDP registrations The process is outlined in more detail as follows: 1. ITU-T: ITU-T H.248 protocol specifications reuse existing IANA-registered S
40、DP codepoints, but could identify additional SDP codepoints, as for example those that are the subject of dedicated use cases. Such extensions to the ITU-T H.248 gateway control protocol are normally related to new ITU-T H.248 “package“ definitions, which are published as part of the ITU-T H.248.x-s
41、eries of Recommendations. However, new SDP codepoints could be also derived as the result of (package-less) ITU-T H.248 procedures or as a result of specific SDP usage according to an ITU-T H.248 “profile“. 2. ITU-T: This Supplement is used as a repository for: a) the documentation of already regist
42、ered ITU-T H.248-specific SDP codepoints with IANA; and b) the collection of newly identified codepoints. 3. IETF: MMUSIC, the IETF multiparty multimedia session control working group, is presently responsible for the SDP. The content of this ITU-T supplement is mapped onto an IETF draft, for exampl
43、e IETF IANA SDP (due to become an RFC), which becomes the baseline for the IANA registration request. 4. IANA: Registration on request by IETF. The process is not a single activity but rather is open to recurrent updates because: ITU-T Supplements support “Release“ versions; and IETF RFCs could be r
44、eplaced (obsoleted) by new RFCs. 4 H series Supplement 14 (10/2015) 6.2 Background information on IANA registration process IETF IANA REG describes the IANA registration process and guidelines for writing IANA considerations. There is a specific situation where an existing IANA registry is requested
45、 to be updated from outside the IETF. IETF RFC 4566 represents the framework document for SDP codepoints and its clause 8 contains the IANA consideration section. In order to be consistent with IETF IANA REG, the following policies are particularly relevant: Registration policy: The same policy appl
46、ies as for the core RFC of the SDP (i.e., IETF RFC 4566). This is the well-known registration policy “RFC required“ (clause 4.7 of IETF IANA REG), which is a superset of policies “Experts review“ and “Specification required“. The importance of the concerned SDP codepoints justifies such a stringent
47、registration policy. Registration requirements: The requirements related to documentation and update of existing registrations (according to clause 3 of IETF IANA REG) are covered. Contact person: It is recommended that the contact (in the IANA registry) for the SDP codepoints requested is the ITU-T
48、 TSB, due to the aspects related to “private persons“ as outlined in clause 9.5 of IETF IANA REG. 7 SDP codepoints for IANA registration 7.1 SDP codepoints related to wildcarding The ITU-T H.248-specific SDP wildcards “-“, “, “r“, “l“ and “0-F“ (see ITU-T H.248.39) can be used in various SDP lines a
49、nd line fields, see Table 1. Such wildcards represent a codepoint space, but are outside of the scope of any IANA registry. NOTE The wildcard characters are compliant with the SDP grammar according to IETF RFC 4566. Table 1 SDP codepoints related to wildcarding Type SDP name (value) Reference Various SDP field elements “-“, “, “r“, “l“ and “0-F“ ITU-T H.248.39 7.2 SDP codepoints related to SDP “m=“ lin
