1、INTERNATIONAL TELECOMMUNICATION UNION ITU=T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Q.732.7 SERIES Q: SWITCHING AND SIGNALLING Specifications of Signalling System No. 7 - ISDN supplementary servi ces (07196) Stage 3 description for call offering supplementary services using Signalling System
2、 No. 7: Explicit Call Transfer ITU-T Recommendation Q.732.7 (Previously CCITT Recommendation) ITU-T Q-SERIES RECOMMENDATIONS SWITCHING AND SIGNALLING , Signalling connection control part Q.i-Q.3 Q.4-Q.59 Q.60-Q.99 Q.100-Q.119 Q. 120-Q.249 Q. 2 50-Q . 309 Q.3 1 O-Q. 399 Q.400-Q.499 Q.500-Q.599 Q.600-
3、Q.699 Q. 700-Q . 849 Q.700 Q.701-Q.709 Q.711-Q.719 Telephone user part Q.720-Q.729 Data user part Q.740-Q. 749 Signalling System No. 7 management Q.750-Q.759 ISDN user part Q. 760-Q. 769 Transaction capabilities application part Q.770-Q.779 Test specification Q.780-Q.799 Q3 interface Q .800-Q. 849 D
4、IGITAL SUBSCRIBER SIGNALLING SYSTEM No. I Q.850-Q.999 PUBLIC LAND MOBILE NETWORK Q. 1000-Q. 1 O99 INTERWORKING WITH SATELLITE MOBILE SYSTEMS Q.1100-Q.1199 INTELLIGENT NETWORK Q. 1200-Q. 1999 BROADBAND ISDN Q.2000-Q.2999 I For further details, please refer to ITU-T List of Recommendations. STD*ITU-T
5、RECMN d.732-7-ENGL 277b 48b2572 Ob31238 827 = ITU-T RECOMMENDATION 4.732.7 STAGE 3 DESCRIPTION FOR CALL OFFERING SUPPLEMENTARY SERVICES USING SIGNALLING SYSTEM No. 7: EXPLICIT CALL TRANSFER Summary This Recommendation defines the essential functions, procedures and messages of the ISUP protocol requ
6、ired for the provisioning to ISDN users of the Explicit Call Transfer supplementary service, which enables a user who has two calls, each of which can be an incoming call or an outgoing call to connect together the other users in the two calls into one call. Source ITU-T Recommendation 4.732.7 was p
7、repared by ITU-T Study Group 11 (1993-1996) and was approved under the WTSC Resolution No. 1 procedure on the 9th of July 1996. STD-ITU-T RECMN Q.732-7-ENGL L99b m i(Bb2541 Ob31239 7b5 FOREWORD IT (International Telecommunication Union) is the United Nations Specialized Agency in the field of teleco
8、mmunications. The JT Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. 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 T
9、elecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid dow
10、n in WTSC Resolution No. 1. In some areas of information technology 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 telecommunicat
11、ion administration and a recognized operating agency. INTELLECTUAL PROPERTY RIGHTS The ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. The ITU takes no position concerning the evidence, va
12、lidity or applicability 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, the IT hadhad not received notice of intellectual property, protected by patents, which may
13、 be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database. O ITU 1997 All rights reserved. No part of this publication may be reproduced or utilized in any
14、form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. 11 Recommendation Q.732.7 (07/96) 7 7.1 7.2 7.3 I 7.4 7.5 I 7.6 , 7.6.1 7.6.2 7.6.3 7.6.4 7.6.5 7.6.6 7.6.7 7.6.8 7.6.9 7.6.1 O 7.6.1 1 7.6.12 7.6.13 7.6.14 7.6.15 7.6.16
15、 7.6.17 CONTENTS Explicit call transfer Introduction 7.1.1 Scope . 7.1.2 References . 7.1.3 Terms and definitions Description . 7.2,l General description 7.2.2 Specific terminology . 7.2.3 7.2.4 Qualifications on the applicability to telecommunication services . State definitions . :; Operational re
16、quirements . 7.3.1 Provisionwithdrawal 7.3.2 Requirements on the originating network side 7.3.3 7.3.4 Requirements on the destination network side Coding requirements Signalling requirements 7.5.1 Activatioddeactivatiodregistration Requirements in the network . 7.5.2 Invocation and operation . Inter
17、action with other supplementary services . Call Waiting (CW) Call transfer services . Connected line identification presentation (COLP) Connected line identification restriction (COLR) . Calling Line Identification Presentation (CLIP) . Calling Line Identification Restriction (CLIR) . Closed User Gr
18、oup (CUG) Conference calling (CONF) Direct-Dialling-In (DDI) . Call diversion (call forwarding) service; (CDIV) . Line Hunting (LH) Three-Party Service (3PTY) User-to-User Signalling (UUS) . Multiple Subscriber Number (MSN) . Call hold (HOLD) . Advice of Charge (AOC) . : Sub-addressing (SUB) . Recom
19、mendation Q.732.7 (07/96) Page 1 1 1 1 2 2 2 2 3 3 3 3 3 3 3 3 8 8 8 13 13 13 14 14 14 14 14 14 14 14 14 14 14 15 15 15 15 iii 7.6.18 7.6.19 7.6.20 7.6.21 7.6.22 7.6.23 7.6.24 Page Terminal Portability (TP) 15 Completion of Calls to Busy Subscriber (CCBS) . 15 Malicious Call Identification (MCID) .
20、15 Reverse charging (REV) . 15 Multi-Level Precedence and Preemption (MLPP) 15 Private Numbering Plan (PNP) . 15 International Telecommunication Charge card . 15 7.7 Interaction with other networks 16 7.8 Signalling flows 16 7.9 Parameter value (timers) . 17 Annex A . 22 iv Recommendation 4.732.7 (0
21、7/96) Recommendation Q.732.7 STAGE 3 DESCRIPTION FOR CALL OFFERING SUPPLEMENTARY SERVICES USING SIGNALLING SYSTEM No. 7: EXPLICIT CALL TRANSFER (Geneva, 1996) 7 Explicit call transfer 7.1 Introduction 7.1.1 Scope The explicit call transfer (ECT) enables a user who has two calls, each of which can be
22、 an incoming call or an outgoing call, to connect together the other users in the two calls into one call. 7.1.2 References The following ITU-T Recommendations and other references contain provisions which, through reference in text, constitute provisions of this Recommendation. At the time of publi
23、cation, the editions indicated were valid. All Recommendations and other references are subject to revision; all 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 o
24、f the currently valid ITU-T Recommendations is regularly published. ITU-T Recommendation 1.1 12 (1993), Vocabulary of terms for ISDNs. CCITT Recommendation I. 130 (1 988), Method for the characterization of telecommunication services supported by an ISDN and network capabilities of an ISDN. ITU-T Re
25、commendation 1.2 1 O (1 993), Principles of telecommunication services supported by an ISDN and the means to describe them. CCITT Recommendation 1.250 (1988), DeJinition of supplementary services. CCITT Recommendation E. 164 (1 991), Numberingplan for the ISDN era. ITU-T Recommendation 1.252.71, Cal
26、l ofsering supplementary services: Explicit Call Transfer. ITU-T Recommendation Q.82.7 (1 996), Stage 2 description for call ofsering supplementary services: Explicit Call Transfer. ITU-T Recommendation 4.730 (1 993), ISDN supplementary services. ITU-T Recommendation Q.761 (1993), Functional descrip
27、tion of the ISDN user part of Signalling System No. 7. ITU-T Recommendation 4.762 (1993), General function of messages and signals of the ISDN user part of Signalling System No. 7. ITU-T Recommendation Q.763 (1993), Formats and codes of the ISDN user part of Signalling System No. 7. Presently at the
28、 stage of draft. Recommendation Q.732.7 (07/96) 1 121 13 14 i 51 ITU-T Recommendation 4.764 (1 993), ISDN user part signallingprocedures. ITU-T Recommendation 4.952 (1993), Stage 3 service description for call oflering supplementary services using DSS 1 - Diversion supplementary services. ITU-T Reco
29、mmendation Q.73 1 (1993), Stage 3 description for number identzjkation supplementary services using Signalling System No. 7. ITU-T Recommendation 4.737.1 (1993), Stage 3 description for additional information transfer supplementary services using SS No. 7: User-to- User Signalling (VUS). , I 7.1.3 T
30、erms and definitions This Recommendation defines the following terms. 7.1.3.1 user A: The served user who invokes the ECT supplementary service. 7.1.3.2 user B: The other user in one of the user As calls. By convention, in this Recommendation, it is considered that this user is the one involved in a
31、n answered call. I l 7.1.3.3 user C: The other user in another of user As calls. 7.1.3.4 call A-B: The (answered) call between user A and user B. 7.1.3.5 call A-C: The (answered or alerting) call between user A and user C. 7.1.3.6 call B-C: The call between user B and user Cy i.e. the call between t
32、he remote parties after ECT supplementary service has been completed. 7.1.3.7 remote party number: The number which identifies the remote party. 7.1.3.8 remote partys subaddress: The subaddress associated with the remote party 7.1.3.9 subaddress: See clause 12E.164 5. 7.2 Description 7.2.1 General d
33、escription The ECT supplementary service enables a user (user A) to transform two of that users calls, each of which can be an incoming call or an outgoing call, into a new call between user B and user C. After the call transfer has occurred, each remote party involved may release the new call accor
34、ding to the basic call procedure as specified in 2.2/Q.764 12. NOTE - The new call between the remote users shall no longer be under user As control since the served user is simultaneously disconnected (see clause 7/Q.952 131). The request for ECT supplementary service shall be rejected if, as a net
35、work option (see 7.5.2.1.1.2.1), it can be determined that the resulting connection would lead into a loop in the network. The stage 1 ITU-T definitions for the ECT supplementary service are given in Recommendation 1.252.7 6. The stage 2 ITU-T description for the ECT supplementary service is given i
36、n Recommendation Q.82.7 7. The stage 3 DSS 1 ITU-T description for the ECT supplementary service is given in clause 7/Q.952 13. This stage 3 description of the ECT supplementary service uses ISDN User Part protocol as defined in Recommendations 4.761 9, 4.764 12 and 4.730 8. 7.2.2 Specific terminolo
37、gy See 7.1.3, Terms and definitions. 2 Recommendation Q.732.7 (07/96) STD-ITU-T RECMN Q*732*7-ENGL L77b 98b2571 Ob31294 O22 M Value Call transfer 7.2.3 Qualifications on the applicability to telecommunication services can be found in 2.3A.252.7 6. Qualifications on the applicability to telecommunica
38、tion services , Code O000 0001 7.2.4 State definitions No specific state definitions are required. 7.3 Operational requirements 7.3.1 Provisiodwithdrawal Provision and withdrawal of the ECT supplementary service are specified in 3.1A.252.7 6. 7.3.2 Not applicable. Requirements on the originating net
39、work side 7.3.3 Requirements in the network The network supporting the ECT supplementary service procedures should have the capability to support the propagation delay and echo control procedures according to 2.6/Q.764 and 2.7/Q.764 12, respectively. 7.3.4 Not applicable. Requirements on the destina
40、tion network side 7.4 Coding requirements The ECT supplementary service requires the use of the following messages: - Call progress (CPG); - Facility (FAC); and - Loop prevention (LOP). The format and coding of the Facility and Call progress messages are given in Recommendation Q.763 i i, Table 45/Q
41、.763 i i and Table 2314.763 i i, respectively. The Facility message is used according to the Service Activation procedure defined in 1.3.1/Q.730 8. Clause 3/Q.763 i i gives the format of the Service activation parameter; for this description, the Feature code used in the Service activation parameter
42、 is given in Table 7-1. For this description, parameters which are relevant to the Facility messcrge are: - Service activation; - Generic notification indicators; - Call transfer number; and - Access transport. Table 7-UQ.732.7 - Feature code assigned to the Service activation parameter For this des
43、cription, the Call progress message is used with the Event indicator subfield, in the Event information parameter (see clause 314.763 i i), set to “PROGRESS“. For this description, parameters which are relevant to the Call progress message are: Recommendation 4.732.7 (07/96) 3 STD=ITU-T RECMN Q-732.
44、7-ENGL 177b 4Ab2571 Ob31245 Tb7 F O O O O o - Generic notification indicators; and - Call transfer number. The Loop prevention message is sent in either direction when the loop prevention procedure is performed (see 7.5.2.1.1.2.1). The message type code for the Loop prevention message is given in Ta
45、ble 7-2. i l Table 7-2/Q.732.7 - Loop prevention message type code I Messagetypecode I Code I I oopprevention I O i 00 0000 I The format of the Loop prevention message is given in Table 7-3. Table 7-3/Q.732.7 - Loop prevention message Parameter (octets) I Type Length Message type Loop prevention ind
46、icators Call transfer reference Message compatibility information Parameter compatibility information End of optional parameters 1 3 3 4 4-? 1 The Message compatibility information and Parameter compatibility information parameters are included in the Loop prevention message according to 6.2.UQ.761
47、and 6.2.2/Q.761 9, respectively. The parameters which may be conveyed, when appropriate (see 7.5), by the Facility, Call progress and Loop prevention messages are the following: - Generic notification indicator; - Access transport; - Call transfer number; - Loop prevention indicators; - Call transfe
48、r reference. 9 Generic notijcation indicator parameter The Generic notification indicator parameter (see also clause 3Q.763 i i) is used to noti one remote user that the call is now transferred to another user; it also gives an indication on the state of the new call (Le. answered or alerting). Tabl
49、e 7-4 shows the value used in the Notification indicator subfield of the Generic notification parameter, for this purpose. 4 Recommendation Q.732.7 (07/96) STD-ITU-T RECMN Q=732-7-ENGL 179b 4862573 Ob31246 7T5 W Notification Call transfer, alerting Call transfer, active Code Call state 110 1001 alerting 110 1010 answered Table 74Q.732.7 - Call transfer number parameter code Parameter name Call transfer number Code O100 O101 The format of the Call transfer number parameter is shown in Figure 7-1. 8 7 6 5 4 3 2 1 Odd/ even Spare
