1、CCITT RECMN*E.353 92 = 4862593 0574377 975 m INTERNATIONAL TELECOMMUNICATION UNION CCITT THE INTERNATIONAL TELEGRAPH AND TELEPHONE CONSULTATIVE COMMITTEE E.151 (08/92) TELEPHONE NETWORK AND ISDN OPERATION, NUMBERING, ROUTING AND MOBILE SERVICE TELEPHONE CONFERENCE CALLS Recommendation E.151 INTERNAT
2、IONAL TELECOMMUNICATION UNION CCITT THE INTERNATIONAL TELEGRAPH AND TELEPHONE CONSULTATIVE COMMITTEE TELEPHONE NETWORK AND ISDN OPERATION, NUMBERING, ROUTING AND MOBILE SERVICE E.151 (08/92) TELEPHONE CONFERENCE CALLS , Recommendation E.151 CCITT RECMN*E*L5L 92 48b259L 0574379 748 FOREWORD The CCITT
3、 (the International Telegraph and Telephone Consultative Committee) is a permanent organ of the International Telecommunication Union (ITU). CCllT is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to stanhdizing telecommunications o
4、n a worldwide basis. The Plenary Assembly of CCIT which meets every four years, establishes the topics for study and approves Recommendations prepared by its Study Groups. The approval of Recommendations by the members of CCllT between Plenary Assemblies is covered by the procedure laid down in CCIT
5、T Resolution No. 2 (Melbourne, 1988). Recommendation E.151 was revised by Study Group I and was approved under the Resolution No. 2 procedure on the 4th of August 1992. CC NOTE In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication admini
6、smtion and a recognized private operating agency. O ITU 1992 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 microfilm, without permission in writing from the ITU. CCITT RECMN*E.LSL 92 W
7、4862591 0574380 4bT -2 Recommendation E.151 TELEPHONE CONFERENCE CALLS (revised 1992) 1 Scope A conference call is one in which three or more locations are coected through a bridging arrangement. Conference calls may be accepted in the international public telephone service by agreement between the
8、Administrations concerned. 2 Types of conference calk Conference calls are normally of two types: - - bidirectional calls in which each participant can listen and speak; unidirectional calis in which only one of the participants can speak, the other participants being able only to listen. However, a
9、 conference call may consist of both types of cail defined above. 3 Operating conditions 3.1 calls. The technical equipment shall in every case be such that good quality of service is guaranteed for conference 3.2 available in the Administrations concerned. Conference calls may be set up by automati
10、c, semi-automatic or manual working, according to the facilities 4 4.1 4.1.1 4.1.2 5 5.1 Setting up a call by automatic working Where the assistance of an operator is not required to establish the conference, the conference originator accesses the conference bridge and dials the conference participa
11、nts directly, or the conference participants dial into the conference bridge facility at a predetermined time. Setting up a call by semi-automatic or manual working In setting up a conference cail, one of two configurations may be used a) The operator of the country in which the originator is locate
12、d connects all the called subscribers to the appropriate equipment. Each foreign participant will therefore be connected by an international circuit and the connection configuration wiii thus take the form of a single-star network. The operator in the country in which the originator is located asks
13、the operator in one or more foreign international exchanges with the appropriate equipment to call and connect the called subscribers, through that equipment, to the equipment of the international exchange of the Administration in the country of origin. In this way, several interconnected star netwo
14、rks will be created. b) Recommendation E.151 (08/92) 1 CCITT RECMN$E-353 92 4862593 0574363 3Tb The choice of the dguration to be used for setting up each conference cail shail be left to the operator in the controlling exchange (that is, the operator in the intemational outgoing exchange which has
15、the appropriate equipment). It should be noted that there are significant operating advantages in the single star network, in terms of setting-up, charging and supervision of the d. 5.2 or individuals (or with additional stations). All or some of the communications making up conference cas may be se
16、t up either with specified stations 5.3 Conference calls may be granted priorities in each relation concerned for all or some of the calls involved, in accordance with the provisions cited in Recommendation E.1411. These calls shall normally take their turn, depending on their class and the priority
17、 with which they were requested. Nevertbeless, in view of their special nature, efforts should be made to set them up as near as possible to the time specified by the originator due regard being paid to the availability of circuits and special equipment. 5.4 these facilities to conference calls. Adm
18、inistrations which accept collect charge card or credit card facilities for telephone calls may extend 6 Charging and accounting for conference calls 6.1 Recommendation E.230 2 shall be applied. In determining the chargeable duration of an international conference call, the basic principles outlined
19、 in 6.2 The tariff and accounting provisions applicable to conference calis are contained in Recommen- dation D.110 3. Note - Some Administrations offer the facility of setting up conference calls, treated as personal calk or stations calls, with the introduction or withdrawal of participants, on re
20、quest, during the call. The introduction of such a service is a national affair and is not contrary to the provisions of the present Recommendation, provided that the bridging equipment for conference calls is used solely in the country of origin and that the call with each of the participants situa
21、ted outside the country of origin appears in the international accounts as a separate international call of the appropriate type between the country of origin and the country of each of the participants. References il CCITT Recommendation Instructionsfor the International Telephone Service, Blue Book, Rec. E.141, ITU, Geneva 1988. 121 CC Recommendation Chargeable duration of calls, Rec. E.230, ITU, Geneva 1992. 31 CC Recommendation Charging und accounting for conference calls, Rec. D. 1 10, IT, Geneva 1992. 2 Recommendation E.151 (OW2)
