1、INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOM M U N I CATI ON STANDARDIZATION SECTOR OF ITU Hm450.1 I (03/200 1 ) SERIES H: AUDIOVISUAL AND MULTIMEDIA SYSTEMS Su p p I e m e n ta ry servi ces for mu It i m ed i a Call intrusion supplementary service for H.323 ITU-T Recommendation H.450.11 (For
2、merly CCITT Recommendation) ITU-T H-SERIES RECOMMENDATIONS AUDIOVISUAL AND MULTIMEDIA SYSTEMS CHARACTERISTICS OF VISUAL TELEPHONE SYSTEMS INFRASTRUCTURE OF AUDIOVISUAL SERVICES General Transmission multiplexing and synchronization Systems aspects Communication procedures Coding of moving video Relat
3、ed systems aspects SYSTEMS AND TERMINAL EQUIPMENT FOR AUDIOVISUAL SERVICES _I_ - I- SUFPLEMENTARY _ SERVICES FOR MULTIMEDIA _- -_ H. 100-H. 199 H.200-H.219 H.220-H.229 H.230-H.239 H.240-H.259 H.260-H.279 H.280-H.299 H.300-H.399 H.450-H.499- Il For further details, please refer to the list of ITU-T R
4、ecommendations. ITU-T Recommendation H.450.11 Call intrusion supplementary service for H.323 Summary This Supplementary Service describes the procedures and the signalling protocol for the Call Intrusion supplementary service in H.323 (Packet Based Multimedia Communications Systems) networks. The Ca
5、ll Intrusion supplementary service (SS-CI) enables a calling user A, encountering a busy destination user B, to establish communication with user B by breaking into an established call between user B and a third user C. This Recommendation makes use of the “Generic functional protocol for the suppor
6、t of supplementary services in H.323“ as defined in ITU-T H.450.1. This Recommendation requires H.323 version 2 (1998) or later. Version 2 products can be identified by H.225.0 messages containing a protocolIdentifier = itu-t (O) recommendation (O) h (8) 2250 version (O) 2) and H.245 messages contai
7、ning a protocolIdentifier = itu-t (O) recommendation (O) h (8) 245 version (O) x, where “XI is 3 or higher. The procedures and the signalling protocol of this Recommendation are derived from the Call Intrusion supplementary service specified in ISO/IEC 14845 and ISO/IEC 14846. Source ITU-T Recommend
8、ation H.450.11 was prepared by ITU-T Study Group 16 (2001-2004) and approved under the WTSA Resolution 1 procedure on 1 March 2001. ITU-T H.450.11 (03/2001) 1 FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU
9、 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 Standardiza
10、tion 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 techn
11、ology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with IS0 and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. INTELLEC
12、TUAL 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, validity or applicability of claimed Intellectual Property Rights, wheth
13、er 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 required to implement this Recommendation. However, implementors are cau
14、tioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database. O ITU 2001 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and m
15、icrofilm, without permission in writing from ITU. 11 ITU-T H.450.11 (03/2001) CONTENTS 1 2 3 4 5 5.1 5.2 5.3 5.4 6 7 7.1 Scope . References . Terms and definitions . Abbreviations and acronyms SS-CI service description Implementation options Provision of capability and protection levels 5.3.1 Activa
16、tioddeactivatiodregistratiodintenogation . 5.3.2 Invocation and operation . 5.3.3 Exceptional procedures Interactions with other supplementary services Call Forwarding Unconditional (SS-CFU) Call Forwarding on No Reply (SS-CFNR)/Call Deflection (SS-CD) . Normal procedures 5.4.1 Call Transfer (SS-CT)
17、 . 5.4.2 5.4.3 5.4.4 Call Forwarding Busy (SS-CFB) . 5.4.5 5.4.6 5.4.7 5.4.8 5.4.9 5.4.10 5.4.1 1 5.4.12 5.4.13 5.4.14 Call Hold Call ParWCall Pickup Call Waiting . Message Waiting Indication Name Presentation . Completion of Calls to Busy Subscriber (SS-CCBS) Completion of Calls on No Reply (SS-CCN
18、R) . Call Offer (SS-CO) Common information Call Linkage Messages and information elements . Signalling procedures . Procedure for initial invocation of SS-CI Optional procedure for invocation of isolation Optional procedure for invocation of forced release . Optional procedure for invocation of wait
19、-on-busy Optional procedure for (re-)invocation of SS-CI on a waiting call . Procedure for completion of SS-CI . Actions at user As endpoint . 7.1.1 7.1.2 7.1.3 7.1.4 7.1.5 7.1.6 Page 1 1 1 2 3 3 4 4 4 4 6 6 6 7 7 7 7 7 7 7 7 7 7 8 8 8 8 9 9 9 9 10 10 11 11 . ITU-T H.450.11 (03/2001) 111 7.2 7.3 8 8
20、.1 8.2 9 9.1 9.2 10 10.1 10.2 Actions at user Bs endpoint . 7.2.1 Procedure for invocation of SS-CI 7.2.2 Optional procedures for invocation of isolation 7.2.3 Optional procedures for invocation of forced release . 7.2.4 7.2.5 Actions at user Cs endpoint . Optional procedures for wait-on-busy (WOB)
21、Procedures for completion of SS-CI Interworking and interactions . Interworking with SCN . Protocol interaction between SS-CI and other supplementary services . 8.2.1 Call Transfer (SS-CT) . 8.2.2 8.2.3 8.2.4 Call Forwarding Unconditional (SS-CFU) Call Forwarding Busy (SS-CFB) . Call Forwarding on N
22、o Reply (SS-CFNR)/Call Deflection (SS-CD) . 8.2.5 8.2.6 8.2.7 8.2.8 8.2.9 8.2.10 8.2.1 1 8.2.12 8.2.13 Call Hold Call ParWCall Pickup Call Waiting . Name Presentation . Completion of Calls to Busy Subscriber (SS-CCBS)/on No Reply (SS- CCNR) . Call Offer (SS-CO) Common Information Call Linkage Messag
23、e Waiting Indication Gatekeeper/Proxy actions . Gatekeepedproxy acts on behalf of an endpoint Gatekeepedproxy acts on behalf of endpoint A Gatekeepedproxy acts on behalf of endpoint B Gatekeepedproxy acts on behalf of endpoint C Gatekeeper passes on SS-CI operations to the endpoint . 9.2.1 9.2.2 9.2
24、.3 Dynamic description . Operational model . Signalling flows 10.2.1 Successful SS-CI - direct call signalling 10.2.2 Unsuccessful SS-CI . 10.2.3 Successful SS-CI - GK routed call signalling . Page 11 11 13 14 14 15 15 15 15 15 15 16 16 16 17 17 17 17 17 17 17 17 17 15 18 15 18 18 18 19 19 19 19 25
25、26 iv ITU-T H.450.11 (0312001) Page 10.3 10.4 10.5 10.6 10.7 11 12 12.1 12.2 12.3 Communication between an endpoint A signalling entity (EASE) and its Signalling entity user (for information purposes) . 10.3.1 Table of primitives . 10.3.2 Primitive definition 10.3.3 Parameter definition Communicatio
26、n between an endpoint B signalling entity (EBSE) and its signalling . entity user (for information purposes) 10.4.1 Table of primitives . 10.4.2 Primitive definition 10.4.3 Parameter definition Communication between an endpoint C signalling entity (ECSE) and its signalling . entity user (for informa
27、tion purposes) 10.5.1 Table of primitives . 10.5.2 Primitive definition 10.5.3 Parameter definition Call states 10.6.1 Call states at endpoint A 10.6.2 Call states at endpoint B 10.6.3 Call states at endpoint C Timers . 10.7.1 Timers at endpoint A . 10.7.2 Timers at endpoint B . . . Operations in su
28、pport of Call Intrusion supplementary service . Specification and description language (SDL) diagrams for SS-CI . Behaviour of user As endpoint . Behaviour of user Bs endpoint . Behaviour of user Cs endpoint . 29 29 29 30 30 31 31 32 33 33 33 33 34 34 34 34 35 35 35 35 39 40 45 51 ITU-T H.450.11 (03
29、/2001) V ITU-T Recommendation H.450.11 Call intrusion supplementary service for H.323 1 Scope This Recommendation specifies the Call Intrusion supplementary service (SS-CI), which is applicable to various basic services supported by H.323 multimedia endpoints. Call Intrusion (SS-CI) is a supplementa
30、ry service which, on request from the served user, enables the served user to establish communication with a busy called user (user B) by breaking into an established call between user B and a third user (user C). The service description, the procedures and the signalling protocol of this Recommenda
31、tion are derived from the Call Intrusion supplementary service as specified in ISO/IEC 14845 and 14846. 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 publica
32、tion, the editions 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
33、currently valid ITU-T Recommendations is regularly published. ITU-T H.225.0 (2000), Call signalling protocols and media stream packetization for packet-based multimedia communication systems. ITU-T H.245 (2000), Control protocol for multimedia communication. ITU-T H.248 (2000), Gateway control proto
34、col. ITU-T H.323 (2000), Packet-based multimedia communications systems. ITU-T H.450.1 (1 998), Generic functional protocol for the support of supplementary services in H.323. ITU-T H.450.2 (1 998), Call transfer supplementary service for H. 323. ITU-T H.450.3 (1 998), Call diversion supplementary s
35、ervice for H. 323, ITU-T H.450.4 (1 999), Call hold supplementary service for H. 323. ITU-T H.450.6 (1 999), Call waiting supplementary service for H. 323. ITU-T H.450.10 (2001), Call offer supplementary service for H.323. Terms and definitions This Recommendation defines the following terms: 3.1 bu
36、sy, busy condition: A condition where a destination endpoint engaged in one or more calls cannot accept another incoming call due to resource limitations. NOTE - In the absence of any supplementary services that might modi the behaviour, the endpoint will in this situation send a Release Complete me
37、ssage containing a ReleaseCompleteReason of inConf or a Cause IE with cause value #17, “user busy“; an H.323 endpoint may be busy with one call or may be busy with more than one call depending on implementation. ITU-T H.450.11 (03/2001) 1 3.2 3.3 common information: Supplementary service capability
38、information which may be exchanged between H.323 endpointdentities at call establishment time or during a call. 3.4 conference type connection: A connection between the served user, user B and user C, where all users have user information connection with each other. 3.5 delayed invocation: Invocatio
39、n of SS-CI after the calling user has been informed that a call has failed because of busy at the destination. 3.6 endpoint, gatekeeper, gateway, terminal, user: See ITU-T H.323. 3.7 established call: The active call that is selected for intruding on. 3.8 forced release: The release of the establish
40、ed call on request from the served user. 3.9 immediate invocation: Invocation of SS-CI as part of the initial call setup. 3.10 intruding call: A call in which the served user requests SS-CI. 3.1 1 intrusion state: The condition after establishment of communication between the served user and user B
41、using SS-CI and prior to termination of SS-CI. 3.12 isolation, Held type of connection: The breaking of the user information connection to and from user C during the intrusion state by means of isolating user C. NOTE - For example, user C may be held using the procedures of ITU-T H.450.4. 3.13 proxy
42、: An entity that acts on behalf of an endpoint for the SS-CI procedures. The proxy may or may not be Co-located with the gatekeeper. 3.14 served user, user A: The user who requests SS-CI (calling user). 3.15 silent monitoring type of connection: A connection between the served user, user B and user
43、C, similar to a conference type of connection but with the served user monitoring the established call without users B and C being informed about that fact. 3.16 3.17 3.18 waiting for user B to become not busy. call: Refer to ITU-T H.323. user B: The wanted user that is subject to the call intrusion
44、 (called user). user C: The other user in the established call, also referred to as the unwanted user. wait-on-busy: A condition in which the intruding call is disconnected from user B and is 4 Abbreviations and acronyms This Recommendation uses the following abbreviations: APDU Application Protocol
45、 Data Unit ASN. 1 CICL Call Intrusion Capability Level CIPL Call Intrusion Protection Level EASE Endpoint A Signalling Entity EBSE Endpoint B Signalling Entity ECSE Endpoint C Signalling Entity GK Gatekeeper IE Information Element MC Multipoint Control Abstract Syntax Notation One 2 ITU-T H.450.11(0
46、3/2001) MP Multipoint Processor NFE Network Facility Extension SCN Switched Circuit Network SDL Specification and Description Language ss-CI Supplementary Service Call Intrusion SS-CO Supplementary Service Call Offer WOB Wait On Busy 5 SS-CI service description Call Intrusion (SS-CI) is a supplement
47、ary service which, on request from the served user, enables the served user to establish communication with a busy called user (user B) by breaking into an established call between user B and a third user (user C). On successful intrusion, user C is either connected in a held type of connection, con
48、nected in a conference type connection, connected in a silent monitoring type of connection, or user C is force-released. Upon SS-CI request, if no specific option is requested, either the held type or the conference type of SS-CI is invoked depending on the implementation options supported within u
49、ser Bs endpoint. As an option, the forced release type of SS-CI may be requested by a served user that is authorized appropriately, either within the initial call setup or after the held type or conference type of SS-CI have been invoked successfully. As an option, the silent monitoring type of SS-CI may be requested by a served user that is authorized appropriately. 5.1 Implementation options o Conference type of Connection Upon successful invocation of SS-CI, the served user (user A), user B and user C are merged into a conference type of connection. As an option, users B and
