1、 International Telecommunication Union ITU-T H.450.5TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (03/2013) SERIES H: AUDIOVISUAL AND MULTIMEDIA SYSTEMSInfrastructure of audiovisual services Supplementary services for multimedia Call park and call pickup supplementary services in ITU-T H.323 syste
2、ms Recommendation ITU-T H.450.5 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 Commu
3、nication 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 an
4、d multimedia services H.360H.369 Supplementary 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 collabora
5、tion 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 H.560H.569 B
6、ROADBAND, 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 General aspec
7、ts 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 For further details, please r
8、efer to the list of ITU-T Recommendations. Rec. ITU-T H.450.5 (03/2013) i Recommendation ITU-T H.450.5 Call park and call pickup supplementary services in ITU-T H.323 systems Summary Recommendation ITU-T H.450.5 describes the procedures and signalling protocol scenarios for the Call Park and Call Pi
9、ckup supplementary services in ITU-T H.323 systems. The Call Park supplementary service (SS-PARK) enables User A (the parking user) to place an existing call with User B (the parked user) in a parking position. The call can later be picked up by retrieving the parked party from either the same termi
10、nal where the park took place or from another terminal. The Call Pickup supplementary service (SS-PICKUP) enables the picking-up user to pick up either a parked call or an alerting call. Upon successful invocation of SS-PICKUP, the picking-up user is connected with the parked user or with the callin
11、g user, depending on selection. This Recommendation makes use of the “generic functional protocol for the support of supplementary services in ITU-T H.323 systems“ as defined in Recommendation ITU-T H.450.1. This revision introduces a number of corrections and clarifications by incorporating technic
12、al and editorial corrections from the Implementers Guide for Recommendations of the ITU-T H.323 system (2011). History Edition Recommendation Approval Study Group 1.0 ITU-T H.450.5 1999-05-27 16 2.0 ITU-T H.450.5 2013-03-16 16 ii Rec. ITU-T H.450.5 (03/2013) FOREWORD The International Telecommunicat
13、ion 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 and tariff ques
14、tions 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 Recommendation
15、s 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 Recommendation,
16、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., interoperability or
17、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 that compliance w
18、ith 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, validity or app
19、licability 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 received notice of intellectual property, protected by patents, which may be required to impleme
20、nt 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 reproduced, by any mean
21、s whatsoever, without the prior written permission of ITU. Rec. ITU-T H.450.5 (03/2013) iii Table of Contents Page 1 Scope 1 2 References. 1 3 Terms and definitions . 1 4 Abbreviations and acronyms 3 5 Description 3 5.1 Call park . 4 5.2 Call pickup 4 6 Messages and information elements . 5 7 Proced
22、ures 6 7.1 Actions at the Parking Endpoint A . 6 7.2 Actions at the Parked Endpoint B 6 7.3 Actions at the parked-to endpoint . 8 7.4 Actions at the calling endpoint (SS-PICKUP of an alerting call) 9 7.5 Actions at the alerting endpoint (SS-PICKUP of an alerting call) . 10 7.6 Actions at the served
23、endpoint . 11 7.7 Actions at a pickup group member endpoint 12 7.8 Actions at the picking-up endpoint . 12 7.9 Alternative procedures 13 8 Interworking . 14 8.1 Interworking with SCN 14 8.2 Interworking with other supplementary services . 14 8.3 Interaction with ITU-T H.225.0 parameters . 15 9 Gatek
24、eeper actions 15 9.1 Normal procedures . 15 9.2 Alternative GK procedures for SS-PICKUP of an alerting call . 15 9.3 Alternative GK procedures for SS-PARK and SS-PICKUP of a parked call 17 10 Dynamic description . 17 10.1 Operational model and signal flows . 17 10.2 Communication between a signallin
25、g entity and its signalling entity user (primitives and parameters) 23 10.3 Call states 31 10.4 Timers . 32 11 Operation in support of SS-PARK and SS-PICKUP 33 12 Specification and description language (SDL) diagrams . 37 iv Rec. ITU-T H.450.5 (03/2013) Page 12.1 SS-PARK SDLs 38 12.2 SS-PICKUP SDLs
26、42 12.3 SS-PARK, SS-PICKUP group notifications SDLs 50 Rec. ITU-T H.450.5 (03/2013) 1 Recommendation ITU-T H.450.5 Call park and call pickup supplementary services in ITU-T H.323 systems 1 Scope This Recommendation describes the Call Park (SS-PARK) and the Call Pickup (SS-PICKUP) supplementary servi
27、ces that are applicable to various basic services supported by ITU-T H.323 endpoints. 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
28、 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 IT
29、U-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.225.0 Recommendation ITU-T H.225.0 (2009), Call signalling protocols and media stream packetization for packet-based
30、 multimedia communication systems. ITU-T H.245 Recommendation ITU-T H.245 (2011), Control protocol for multimedia communication. ITU-T H.323 Recommendation ITU-T H.323 (2009), Packet-based multimedia communications systems. ITU-T H.450.1 Recommendation ITU-T H.450.1 (2011), Generic functional protoc
31、ol for the support of supplementary services in ITU-T H.323 systems. 3 Terms and definitions 3.1 Terms defined elsewhere This Recommendation uses the following term defined elsewhere: 3.1.1 call ITU-T H.323: Point-to-point multimedia communication between two ITU-T H.323 endpoints. The call begins w
32、ith the call set-up procedure and ends with the call termination procedure. The call consists of the collection of reliable and unreliable channels between the endpoints. A call may be directly between two endpoints or may include other ITU-T H.323 entities such as a Gatekeeper or MC. In the case of
33、 interworking with some SCN endpoints via a Gateway, all the channels terminate at the Gateway where they are converted to the appropriate representation for the SCN end system. Typically, a call is between two users for the purpose of communication, but may include signalling-only calls. An endpoin
34、t may be capable of supporting multiple simultaneous calls. 3.2 Terms defined in this Recommendation This Recommendation defines the following terms: 3.2.1 alerting call: A basic ITU-T H.323 call that is presented to the called user (alerting state) and has not yet been answered by the called user.
35、During the alerting state, the call may be picked up by any authorized picking-up user. 3.2.2 alerting endpoint/user: The endpoint/user that is being alerted (alerting call), which is picked up by a picking-up user. 2 Rec. ITU-T H.450.5 (03/2013) 3.2.3 calling endpoint/user: The endpoint/user that o
36、riginated a call to the alerting endpoint/user that is picked up by the picking-up user. 3.2.4 directed park: Directed park enables the parking user to park a call at a parking position that is associated with a terminal endpoint. Typically, the parking user explicitly provides the parked-to number
37、that is used to address the parking position. 3.2.5 directed pickup: Directed pickup enables a picking-up user to pick up a parked call or an alerting call by means of explicitly providing the number of a parking position (i.e., parked-to user) or of an alerting user. 3.2.6 group member endpoint/use
38、r: The endpoint/user that is a member of a pickup group and receives a notification about a parked call/alerting call that can be picked up. 3.2.7 group park: Group park enables the parking user to park a call at a parking position that is associated with a pickup group and which may typically be lo
39、cated in a server endpoint. A preconfigured number may be used to address the parking position. 3.2.8 group pickup: Group pickup enables a picking-up user to pick up a parked call or an alerting call that is associated with a group. Typically, a preconfigured number is used to address the parked-to
40、position or the alerting endpoint. 3.2.9 number: A reference to the number of a user (e.g., “number of the parked-to user“ or “number of the alerting user“) is meant to indicate any type of ITU-T H.225.0 alias address (an ITU-T E.164 number, a URL address, an e-mail address, etc.). 3.2.10 parking en
41、dpoint/user; User A: The user/endpoint that invokes SS-PARK during the active state of a call with a User B that results in User B being connected to a parking position. 3.2.11 parked endpoint/user; User B: The user/endpoint that is connected to a parking position following the invocation of SS-PARK
42、 by a parking user. Once User B is parked, the user/endpoint waits to be picked up by a picking-up user. 3.2.12 parking position (parked-to endpoint/entity/user): A place assigned to a parked-to endpoint where the parked endpoint is parked and subsequently from which it is picked up. A parking posit
43、ion may also be located within a gatekeeper. The parking position may allow one call to be parked or more than one call to be parked simultaneously. Depending on the implementation, a particular parking position within a parked-to endpoint may either be explicitly identified (park position), or queu
44、ing concepts may be used for allowing multiple calls to be parked and subsequently picked up. A particular call parked at the parked-to endpoint may explicitly be identified via either the park position or by means of a call identifier. If SS-PICKUP does not provide any explicit information that ide
45、ntifies the call to be picked up, then any parked call at that parked-to endpoint (e.g., the call at the top of a queue) may be selected. The parking position may be located either within an ITU-T H.323 terminal endpoint or within an ITU-T H.323 server endpoint. The definition of parking position ap
46、plies to both directed park and pickup as well as to group park and pickup. The parking position may request that a user that is parking a call shall verify its respective access rights and that a user that is picking up a call shall verify its respective access rights. 3.2.13 picking-up endpoint/us
47、er: A user/endpoint that picks-up a parked call or an alerting call. 3.2.14 pickup group: A group of users that may be notified when one of the group members receives a call that can be picked up. Each group member is authorized to answer the call by using SS-PICKUP. Rec. ITU-T H.450.5 (03/2013) 3 3
48、.2.15 primary call: Call between a parking user and a parked user. 3.2.16 parked call: Call between a parked user and a park position. 3.2.17 served endpoint: A parked-to endpoint or an alerting endpoint that indicates to pick up group members that a parked call/alerting call is available to be pick
49、ed up. 3.2.18 unparking endpoint/user: When picking up a parked call, the picking-up user is also referred to as the unparking user. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: (A)PDU (Application) Protocol Data Unit ASN.1 Abstract Syntax Notation One GK Gatekeeper MC Multipoint Controller NFE Network Facility Extension SCN Switched Circuit Network SDL Specification and Description Language SS Supplementary Service SS-PARK Supplementary Service Call Park SS-PICKUP Supplem
