1、 International Telecommunication Union ITU-T H.460.7TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (03/2013) SERIES H: AUDIOVISUAL AND MULTIMEDIA SYSTEMSInfrastructure of audiovisual services Supplementary services for multimedia Digit maps within ITU-T H.323 systems Recommendation ITU-T H.460.7 IT
2、U-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.240H.259 Cod
3、ing 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.360H.369 S
4、upplementary services for multimedia H.450H.499MOBILITY 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 services H.5
5、20H.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 AND ADVANCED
6、 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 terminal device
7、s 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-T Recommen
8、dations. Rec. ITU-T H.460.7 (03/2013) i Recommendation ITU-T H.460.7 Digit maps within ITU-T H.323 systems Summary Recommendation ITU-T H.460.7 specifies the usage of Digit Maps within ITU-T H.323 systems. Digit Maps can improve the post dial delay experienced by the user and can reduce the amount o
9、f provisioning that would otherwise have to occur in order to reduce such delays. This revision introduces a number of corrections and clarifications by incorporating technical and editorial corrections from the ITU-T H.323-series Implementers Guide (03/2011). History Edition Recommendation Approval
10、 Study Group 1.0 ITU-T H.460.7 2002-11-29 16 2.0 ITU-T H.460.7 2013-03-16 16 ii Rec. ITU-T H.460.7 (03/2013) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The IT
11、U Telecommunication 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 Standardiz
12、ation Assembly (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 tech
13、nology which 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. Complia
14、nce with this 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 obli
15、gatory language 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 implementati
16、on of this Recommendation 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
17、 the date of approval of this Recommendation, ITU had not 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
18、 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 reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T H.460.7 (03/2013) iii Table of Contents Page 1 Scope 1 2 References. 1 3 Abb
19、reviations and acronyms 1 4 General considerations 2 5 Capability advertisement 2 6 Conveyance of digit maps 4 6.1 Use of the RCF message . 4 6.2 Use of the SCI message 4 6.3 Timer parameters 5 6.4 Digit map string parameters . 6 6.5 URL parameter . 7 7 Overlapped sending 8 8 Digit map timers and ma
20、tching strings . 8 9 Format of digit map information data stream retrieved via HTTP . 10 10 Digit Map string syntax 11 Rec. ITU-T H.460.7 (03/2013) 1 Recommendation ITU-T H.460.7 Digit maps within ITU-T H.323 systems 1 Scope This Recommendation defines the usage of Digit Maps within ITU-T H.323 syst
21、ems. Digit Maps can improve the post dial delay experienced by the user and can reduce the amount of provisioning that would otherwise have to occur in order to reduce such delays. A Digit Map is a set of textual strings that serve as a template representing the dialling plan available to the endpoi
22、nt. Digit Map information is conveyed from the gatekeeper to the endpoint following registration. The advertisement of capabilities and the conveyance of Digit Maps are performed through the use of the Generic Extensibility Framework, as defined in ITU-T H.323. 2 References The following ITU-T Recom
23、mendations and other references 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 th
24、erefore 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-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a st
25、and-alone document, the status of a Recommendation. ITU-T H.225.0 Recommendation ITU-T H.225.0 (2009), Call signalling protocols and media stream packetization for packet-based multimedia communication systems. ITU-T H.248.1 Recommendation ITU-T H.248.1 (2005), Gateway control protocol: Version 3. I
26、TU-T H.323 Recommendation ITU-T H.323 (2009), Packet-based multimedia communications systems. ITU-T Q.931 Recommendation ITU-T Q.931 (1998), ISDN user-network interface layer 3 specification for basic call control. ITU-T T.50 Recommendation ITU-T T.50 (1992), International Reference Alphabet (IRA) (
27、Formerly International Alphabet No. 5 or IA5) Information technology 7-bit coded character set for information interchange. IETF RFC 2234 ISOC/IETF RFC 2234 (1997), Augmented BNF for Syntax Specifications: ABNF. IETF RFC 2616 ISOC/IETF RFC 2616 (1999), Hypertext Transfer Protocol HTTP/1.1. 3 Abbrevi
28、ations and acronyms This Recommendation uses the following abbreviations and acronyms: ABNF Augmented Backus-Naur Form ARJ Admission Reject ARQ Admission Request GEF Generic Extensible Framework HTTP Hypertext Transfer Protocol RAS Registration, Admission and Status 2 Rec. ITU-T H.460.7 (03/2013) RC
29、F Registration Confirm RRQ Registration Request SCI Service Control Indication SCR Service Control Response ToN Type of Number 4 General considerations A Digit Map is a collection of strings that represent valid dialling plans. The exact syntax of each string is defined in clause 10. The Digit Map i
30、nformation should be used by the endpoint to expeditiously detect a complete number so as to reduce the post-dial delay experienced by the calling user. The Gatekeeper may provide a primary Digit Map for use when the Type of Number is unknown, and separate Digit Maps that are associated with a parti
31、cular Type of Number that is known. In the event that the Gatekeeper does not provide a Digit Map for a particular Type of Number, or in the case that the endpoint or environment has no concept of a Type of Number, the endpoint shall match numbers against the primary Digit Map. Digit Maps may be pro
32、vided directly through RAS signalling, or referenced by a URL provided through RAS signalling. 5 Capability advertisement Endpoints capable of accepting, and willing to accept, Digit Maps from the Gatekeeper shall advertise that capability in all RRQ messages sent to the Gatekeeper, except lightweig
33、ht RRQ messages. The capability shall not be advertised in lightweight RRQ messages. If the capability is not present in the aforementioned RRQ messages, the Gatekeeper shall assume that Digit Map support is no longer present. An endpoint signals support for Digit Maps by advertising the capability
34、in the featureSet.supportedFeatures field of the RRQ message. The Digit Maps capability is indicated with the feature identifier shown in Table 1. Table 1 Indication of the Digit Maps feature Feature name: Digit Maps Feature Description: This feature allows a Gatekeeper to transmit Digit Map informa
35、tion and for an endpoint to use that information in accordance with this Recommendation Feature identifier type: Standard Feature identifier value: 7 The endpoint shall provide the parameter that indicates the total number of bytes of memory that the endpoint can allocate to store the Digit Maps pro
36、vided by the Gatekeeper. That parameter is shown in Table 2. Rec. ITU-T H.460.7 (03/2013) 3 Table 2 Digit Maps Length Parameter name: Digit Maps Length Parameter description: This value represents the total number of bytes of memory that the endpoint can allocate to store the Digit Maps provided by
37、the Gatekeeper, either through RAS or HTTP. A length of 0 indicates that the endpoint does not impose a limit on the length of the Digit Map information it will accept. Parameter identifier type: Standard Parameter identifier value: 1 Parameter type: number32 Parameter cardinality: Once The endpoint
38、 may provide the parameter described in Table 3, which indicates the total number of bytes of memory that the endpoint can allocate to store a temporary Digit Map information provided by the Gatekeeper in an ARJ message when doing overlapped sending. The absence of this parameter indicates that the
39、endpoint does not support the reception of a Digit Map for use within the context of overlapped sending via RAS. If the endpoint wishes to indicate the ability to accept a temporary Digit Map within the context of overlapped sending without specifying a maximum amount of memory, the value of this pa
40、rameter shall be set to zero. Table 3 Digit Map Length for Overlapped Sending Parameter name: Digit Maps Length for Overlapped Sending Parameter description: This value represents the total number of bytes of memory that the endpoint can allocate to store the Digit Map provided by the Gatekeeper whe
41、n performing overlapped sending, or 0 if it does not wish to indicate a limit. Parameter identifier type: Standard Parameter identifier value: 2 Parameter type: number32 Parameter cardinality: Zero or one If the endpoint has the ability to transfer Digit Map information via HTTP, it shall include in
42、 the capability advertisement the parameter shown in Table 4 with its value set to TRUE. Otherwise, the parameter shall be included with the value FALSE. Table 4 HTTP Digit Maps Download Capability Parameter name: HTTP Download Capability Parameter description: The presence of this parameter indicat
43、es that the endpoint has the capability of downloading Digit Maps via HTTP. Parameter identifier type: Standard Parameter identifier value: 3 Parameter type: bool Parameter cardinality: Once Other parameters are for further study and shall be ignored if received. 4 Rec. ITU-T H.460.7 (03/2013) 6 Con
44、veyance of digit maps The Gatekeeper may provide Digit Map information to an endpoint that advertises support for the Digit Maps feature. The Digit Map information is conveyed to the endpoint through the RCF (including a response to a lightweight RRQ), SCI, or ARJ messages by populating the genericD
45、ata field with the Digit Map information or with a URL to said information. The Gatekeeper should provide the Digit Map information in the RCF message, but may utilize the SCI message in order to provide updated information in the absence of an RRQ/RCF exchange. Digit Map information may be updated
46、later by the Gatekeeper in any RCF message or any SCI message. Such an update from the Gatekeeper shall result in the replacement of any previously received Digit Map information in RCF or SCI with the new information. The endpoint shall always utilize the most recently transmitted Digit Map informa
47、tion. The Gatekeeper may also provide a more refined, temporary Digit Map as part of the overlapped signalling procedures defined in clause 8.1.12 of ITU-T H.323. In this case, the Digit Map information shall be provided via the ARJ message and shall contain a single Digit Map for the particular Typ
48、e of Number signalled in the related ARQ. Further, the Digit Map shall only have significance with respect to that particular call. This temporary Digit Map shall be the only Digit Map subsequently considered when matching digits for that call, and can only be updated through subsequent ARJ messages
49、. The reception of Digit Map information within an ARJ shall not result in the replacement of Digit Map information provided in an RCF or SCI, as that information would remain valid for other calls that are initiated. Use of the ARJ message is for support of overlapped sending as described more fully in clause 7. NOTE Implementers should be conscientious of the fact that, since RAS is asynchronous in nature, an RCF containing Digit Map information may be received by an endpoint after an SCI message containing a more u
