1、COVERING NOTE GENERAL SECRETARIAT INTERNATIONAL TELECOMMUNICATION UNION Subject: INFORMATION NOTE Geneva, June 1999 Recommendation ITU-T 4.734 (03/93) TE LEC0 M M U N I CAT I ON STANDARDIZATION SECTOR OF ITU ITU-T Recommendation Q.734 (03/93) Stage 3 description for multiparty supplementary services
2、 using Signalling System no. 7 Clause 1 - Conference calling Clause 2 - Three-party service This covering note is to warn readers that the version of ITU-T Q.734.2 (03/93) contained in the volume ITU-T Q.734 (03/93) is “obsolete“, superseded by ITU-T Q.734.2 (07/96) Only ITU-T Q.734.1 (03/93) remain
3、s in force. ITU-T Q.734.2 (03/93) was originally published with ITU-T Q.734.1 (03/93) in the same volume named ITU-T Q.734 (03/93). ITU-T Q.734.2 (07/96) was subsequently published separately. To correct this situation, the electronic version of ITU-T Q.734 (03/93) was split into two, with ITU-T Q.7
4、34.1 (03/93) remaining “in-force“ and ITU-T Q.734.2 (03/93) labelled as “obsolete“. Union internationale des tlcommunications Place des Nations 121 1 GENEVE 20 Suisse Switzerland Suiza COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesINT
5、ERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU S P EC I FI CATI O NS OF SIGNALLING SYSTEM No. 7 Q.734 (03193) STAGE 3 DESCRIPTION FOR MULTIPARTY SUPPLEMENTARY SERVICES USING SIGNALLING SYSTEM No. 7 CLAUSE 1 - CONFERENCE CALLING CLAUSE 2 - THREE-PARTY SERVICE
6、 ITU-T Recommendation Q.734 (Previously “CCITT Recommendation”) COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesFOREWORD The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the International Telecom- municat
7、ion Union. The 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 Standardization Conference (WTSC), which meets every four years, establishe
8、d the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. ITU-T Recommendation Q.734, clauses 1 and 2, was prepared by the ITU-T Study Group XI (1988-1993) and was approved by the WTSC (Helsinki, March 1-12, 1993). NOTES 1 As a consequence of a r
9、eform process within the International Telecommunication Union (ITU), the CCITT ceased to exist as of 28 February 1993. In its place, the ITU Telecommunication Standardization Sector (ITU-T) was created as of 1 March 1993. Similarly, in this reform process, the CCIR and the IFRB have been replaced b
10、y the Radiocommunication Sector. In order not to delay publication of this Recommendation, no change has been made in the text to references containing the acronyms “CCITT, CCIR or IFRB” or their associated entities such as Plenary Assembly, Secretariat, etc. Future editions of this Recommendation w
11、ill contain the proper terminology related to the new ITU structure. 2 telecommunication administration and a recognized operating agency. In this Recommendation, the expression “Admmistration” is used for conciseness to indicate both a O ITU 1994 All rights reserved. No part of this publication may
12、 be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesCONTENTS 1 Conference ca
13、lling . 1.1 1.2 1.3 1.4 1 . 5 1.6 1.7 1.8 1.9 1.10 Definition Description Operational requirements Coding requirements . Signalling requirements Interactions with other supplementary services Interaction with other networks Signalling flows Parameter values (timers) . Dynamic description . 2 Three p
14、arty . 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 Definition Description Operational requirements Coding requirements . Signalling requirements Interactions with other supplementary services Interactions with other networks . Signalling flows Parameter values (timers) . Dynamic description . Recommend
15、ation Q.734 (03/93) Page 1 1 1 2 2 3 6 8 8 16 16 16 16 16 17 17 18 20 22 22 25 25 i COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesCOPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling
16、ServicesRecommendation Q.734 STAGE 3 DESCRIPTION FOR MULTIPARTY SUPPLEMENTARY SERVICES USING SS No. 7 (Helsinki, 1993) 1 Conference calling 1.1 Definition conference calling (CONF) is an ISDN supplementary service which allows a user to communicate simultaneously with multiple parties, which may als
17、o communicate among themselves. 1.2 Description 1.2.1 General description This supplementary service provides a user with the ability to have multi-connection call, i.e. a simultaneous communication between more than two parties. When conference calling is invoked, the conference resources (e.g. a “
18、bridge”) are allocated to the served user and any calls indicated by the service request are allocated to the conference. This description is only applicable in case the conference bridge is located at the local exchange of the served user. Once a conference is active, parties may be added, dropped,
19、 isolated (i.e. prevented from communicating with the conference), reattached or split (i.e. removed from the conference but remain connected to the conference controller). The controller can place her/his connection to the conference on hold, retrieve the conference, disconnect herself/himself from
20、 the conference and release the entire conference. The stage 1 definition for the conference calling supplementary service is given in Recommendation 1.254.1. The stage 2 description for the conference calling supplementary service is given in Recommendation Q.84.1. The stage 3 DSS 1 description is
21、given in Recommendation Q.954.1. This stage 3 description of the conference calling supplementary service uses ISDN user part protocol as defined in Recommendations Q.761-Q.764 and Q.730. 1.2.2 Specific terminology Served user - The user which requests the conference call. The served user will be th
22、e user controlling the conference call. The served user may also be referred to as user A. Conferee - The users involved in the conference not controlling the conference, i.e. all participants except the served user are referred to as conferees or parties. The conferees may also be known as users B,
23、 C, . . . Isolate - An action at the access that restricts communication in both direction with a participant of the conference. Reattach - An action at the access that re-establishes the communication with a participant of the conference. Split - An action at the access that creates a private commu
24、nication between the served user and a remote user. The private communication is a normal “two-party” call. Drop - An action at the access that clears the connection to a remote party. Floating - The situation where the conference calling supplementary service exist without the served user. Recommen
25、dation Q.734 (03/93) COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling Services1.2.3 See stage 1 description, Recommendation 1.254.1. 1.2.4 State definitions No specific state definitions are identified. Qualifications on the applicability to tel
26、ecommunication services 1.3 Operational requirements 1.3.1 Provision/withdrawal See stage 1 description, Recommendation 1.254.1. 1.3.2 Not applicable. 1.3.3 Requirements in the network No specific requirements are needed in the network. 1.3.4 Not applicable. Requirements on the originating network s
27、ide Requirements on the terminating network side 1.4 Coding requirements The call progress message containing the generic notification inL,cator parameter including the notification in Tak,: will be sent towards the remote user when appropriate. TABLE 1-1/Q.734 Generic notification indicator paramet
28、er field Bits 7654321 1000010 100001 1 1000100 1 O001 o1 1000110 10001 11 1 O01 O00 1 O01 O01 1 O01 o1 o 1001011 Description Conference established Conference disconnected Other party added Isolated Reattached Other party isolated Other party reattached Other party split Other party disconnected Con
29、ference floating The event indicator shall be coded O000010 “Progress”. The generic notification indicator parameter is accompanied by the parameter compatibility information parameter. The procedures for compatibility are defined in Recommendation Q.764. 2 Recommendation Q.734 (03/93) COPYRIGHT Int
30、ernational Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling Services1.5 Signalling requirements The following ISUP procedures apply in case network option for user notifications is supported. 1.5.1 Ac tivation/deac tivation/registration Not applicable. 1.5.2 Invocation
31、 and operation 1.5.2.1 Actions at the originating local exchange In this case, the originating exchange is the exchange where the service is controlled. The originating exchange for this service is not necessarily the originating exchange for basic call. 1.5.2.1.1 Normal operation 1.5.2.1.1.1 Requir
32、ements related to echo control a) General The originating local exchange where the conference bridge is located should have the capability to invoke echo control procedures. This is necessary in case the total propagation delay for two legs in the conference is above the value where echo control is
33、necessary (ref. 2.6/Q.764). The exchange must also have the capability of storing propagation delay information received either in a received IAM (for incoming calls) or in ANMICON (for outgoing calls) until call release. This must be done for all legs included in the conference. Criteria to initiat
34、e echo control procedures Upon adding a new call to the conference, the received propagation delay value related to this leg shall be added to each of the other legs to decide whether echo control apply for the legs concerned. b) If echo control is necessary, the exchange will initiate echo control
35、procedures for each of the legs concerned. (2.7/Q.764). 1.5.2.1.1.2 Requesting a conference from an active call and adding conferees Upon successful request to begin the conference from an active call, user B participating in the active call will be added to the conference. A notification “conferenc
36、e established” shall be sent to user B informing that a connection to the conference is now established. The notification is conveyed in a call progress message (CPG). Upon request to add a new conferee (user C) to the conference, a check is performed whether or not the maximum number of conferees i
37、s reached for that conference. Upon the successful outcome of the add-on request, a notification “conference established” is sent to user C informing that connection to the conference is now established. The notification is conveyed in a CPG message. A notification “other party added” is sent in a C
38、PG message towards all the non-affected conferees informing them that a new party is added to the conference call. 1.5.2.1.1.3 Isolate a party The conference controller may request to isolate one conferee from the conference. The conferee is still connected to the conference, but communication in ei
39、ther direction is impossible. A notification “isolated” is sent to the affected conferee informing that he/she is isolated from the conference. The notification is conveyed in a CPG message. A notification “other party isolated” is sent within a CPG message towards all the non-affected conferees inf
40、orming them that one party is isolated from the conference. Recommendation Q.734 (03/93) 3 COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling Services1.5.2.1.1.4 Reattach a party The conference controller may request to reattach the isolated confe
41、ree to the conference. A notification “reattached” is sent to the affected conferee informing that he/she is reattached to the conference. The notification is conveyed in a CPG message. A notification “other party reattached” is sent within a CPG message towards all the non-affected conferees inform
42、ing them that the isolated party is now reattached to the conference call. 1.5.2.1.1.5 Split a party The conference controller may request to create a private communication with one of the conferees (splitting). A notification “conference disconnected” is sent to the affected conferee informing that
43、 he/she is connected to the conference controller only. The notification is conveyed in a ISUP CPG message. A notification “other party disconnected” is sent within a CPG message towards all the non-affected conferees informing them that the conference controller has split off with another party. 1.
44、5.2.1.1.6 Disconnect a party The conference controller may request to disconnect (drop) one or more of the parties on a one at a time basis. Normal release procedures apply towards the dropped conferee(s). A notification “other party disconnected” is sent within a CPG message towards all the non-aff
45、ected conferees informing them that another party is dropped from the conference. 1.5.2.1.1.7 Disconnect by a party A conferee may request to be disconnected from the conference call. Normal release procedure apply for the leg between the conferee and the conference bridge. A notification “Other par
46、ty disconnected” is sent within a CPG message towards all the non-affected conferees informing them that another party has disconnected from the conference. 1.5.2.1.1.8 Terminate the conference The conference controller may request to release the conference. The conference resources shall be release
47、d and normal release procedures apply towards all the conferees. 1.5.2.1.1.9 Disconnect the served user The conference controller may explicitly request to be disconnected from the conference. The conferees will still be connected to the conference. A notification “conference floating” is sent withi
48、n a CPG message towards all the conferees informing them that the conference is now within a floating state, i.e. no conference controller is connected to the conference. The conference resources shall be released when only one conferee is connected to the bridge or requirements for charging cannot
49、be met. Normal basic call release procedures apply towards the remaining conferee. 1.5.2.1.1.10 Call clearing by served user The conference controller may request to disconnect from the conference according to normal basic call procedure. If the conditions for floating are met the served user will be disconnected from the conference bridge, but the conferees will still be connected to the conference. A notification “conference floating” is sent within a call progress message towards all the conferees informing that the conference is now within a floating state, i.e. no conference control
