1、 International Telecommunication Union ITU-T H.248.15TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (03/2013) SERIES H: AUDIOVISUAL AND MULTIMEDIA SYSTEMSInfrastructure of audiovisual services Communication procedures Gateway control protocol: SDP ITU-T H.248 package attribute Recommendation ITU-T
2、H.248.15 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 Ubiquitous sensor network applications and Internet of Things H.640H.649 IPTV MULTIMEDIA SERVICES AND APPLICATIONS FOR IPTV General aspects H.700H.719 IPTV term
7、inal 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 For further details, please refer to the list of ITU
8、-T Recommendations. Rec. ITU-T H.248.15 (03/2013) i Recommendation ITU-T H.248.15 Gateway control protocol: SDP ITU-T H.248 package attribute Summary Recommendation ITU-T H.248.15 describes a new SDP attribute that allows for the carriage of properties in the local and remote descriptor in the textu
9、al ITU-T H.248 encoding. NOTE This Recommendation has been renumbered. It was formerly known as Rec. ITU-T H.248 Annex N. History Edition Recommendation Approval Study Group 1.0 ITU-T H.248.15 2002-03-29 16 2.0 ITU-T H.248.15 2013-03-16 16 ii Rec. ITU-T H.248.15 (03/2013) FOREWORD The International
10、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 responsible for studying technical, operating a
11、nd 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
12、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 basis with ISO and IEC. NOTE In this Re
13、commendation, 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 mandatory provisions (to ensure, e.g., intero
14、perability 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 use of such words does not suggest tha
15、t 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 no position concerning the evidence, v
16、alidity 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, protected by patents, which may be r
17、equired 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 2013 All rights reserved. No part of this publication may be repro
18、duced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T H.248.15 (03/2013) iii Table of Contents Page 1 Scope 1 2 References. 1 3 Definitions 1 4 Abbreviations and acronyms 1 5 Package attribute . 1 6 IANA considerations 2 Rec. ITU-T H.248.15 (03/2013) 1 Recommendatio
19、n ITU-T H.248.15 Gateway control protocol: SDP ITU-T H.248 package attribute 1 Scope This Recommendation is part of the Gateway Control Protocol family of Recommendations and extends the basic functionality in ITU-T H.248.1. This Recommendation describes a new SDP attribute that allows for the carri
20、age of properties in the local and remote descriptor in the textual ITU-T H.248 encoding. The advantages of this approach are: if ITU-T H.248 properties for Local and Remote Descriptor usage are available (due to existing ITU-T H.248 packages from e.g., the ITU-T H.248.x-series of Recommendations),
21、but a correspondent SDP information element is missing, then new SDP attributes do not have to be defined and registered for each property; that the property is defined in one place and is applicable to both binary and textual encodings. 2 References The following ITU-T Recommendations and other ref
22、erences contain provisions 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 in
23、vestigate the possibility 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
24、status of a Recommendation. ITU-T H.248.1 Recommendation ITU-T H.248.1 (2013), Gateway Control Protocol : Version 3. IETF RFC 2327 IETF RFC 2327 (1998), SDP: Session Description Protocol. 3 Definitions This Recommendation uses the terms defined in ITU-T H.248.1. 4 Abbreviations and acronyms This Rec
25、ommendation uses the following abbreviations and acronyms: SDP Session Description Protocol 5 Package attribute The textual encoding of ITU-T H.248.1 uses SDP (as per IETF RFC 2327) to describe the characteristics of media. SDP value attributes provide a means to extend SDP. To enable the carriage o
26、f package defined properties in the local and remote descriptors of the text encoded ITU-T H.248.1 protocol, the Package attribute shall be used. The format of the Package attribute is as below: a=h248item:/ = 2 Rec. ITU-T H.248.15 (03/2013) where: is the textual package name defined in the package
27、is the textual property name defined in the package is the textual property value name defined in the package of the type (i.e., boolean, integer, octet string) defined by the package. For example: Setting Maximum Jitter Buffer in the Network Package described in clause E.11.1 of ITU-T H.248.1. a=h2
28、48item:nt/jit = 2000 6 IANA considerations Contact details: ITU TSB Place des Nations CH-1211 Geneva 20 tsbmailitu.int Attribute-name: h248item Long-form attribute name: H248.1 Package Property Item Type of attribute (session level, media level, or both): both Attribute value is subject to the chars
29、et attribute: no Purpose of the attribute: This attribute allows for the carriage of ITU-T H.248-series/Megaco-defined properties for local and remote to be carried via SDP. Appropriate attribute values: The format of the Package attribute is as below: a=h248item:/ = where: is the textual package na
30、me defined in the package is the textual property name defined in the package is the textual property value name defined in the package of the type (i.e., boolean, integer, octet string) defined by the package.Printed in Switzerland Geneva, 2013 SERIES OF ITU-T RECOMMENDATIONS Series A Organization
31、of the work of ITU-T Series D General tariff principles Series E Overall network operation, telephone service, service operation and human factors Series F Non-telephone telecommunication services Series G Transmission systems and media, digital systems and networks Series H Audiovisual and multimed
32、ia systems Series I Integrated services digital network Series J Cable networks and transmission of television, sound programme and other multimedia signals Series K Protection against interference Series L Construction, installation and protection of cables and other elements of outside plant Serie
33、s M Telecommunication management, including TMN and network maintenance Series N Maintenance: international sound programme and television transmission circuits Series O Specifications of measuring equipment Series P Terminals and subjective and objective assessment methods Series Q Switching and si
34、gnalling Series R Telegraph transmission Series S Telegraph services terminal equipment Series T Terminals for telematic services Series U Telegraph switching Series V Data communication over the telephone network Series X Data networks, open system communications and security Series Y Global information infrastructure, Internet protocol aspects and next-generation networks Series Z Languages and general software aspects for telecommunication systems