1、INTERNATIONAL TELECOM M UN CATION U NION ITU-T TELECOMM U N KATION STANDARDIZATION SECTOR OF ITU Q.82.7 (07/96) SERIES Q: SWITCHING AND SIGNALLING Functions and information flows for services in the ISDN - Supplementary services Stage 2 description for call offering supplementary services: Explicit
2、call transfer ITU-T Recommendation Q.82.7 (Previously CCITT Recommendation) ITU-T Q-SERIES RECOMMENDATIONS SWITCHING AND SIGNALLING SIGNALLING IN THE INTERNATIONAL MANUAL SERVICE INTERNATIONAL AUTOMATIC AND SEMI-AUTOMATIC WORKING Basic Recommendations Numbering plan and dialling procedures in the in
3、ternational service Routing plan for international service General Recommendations relative to signalling and switching systems (national or international) Tones for use in national signalling systems General characteristics for international telephone connections and circuits Signalling for satelli
4、te systems Signalling for circuit multiplication equipment Methodology Basic services FUNCTIONS AND INFORMATION FLOWS FOR SERVICES IN THE ISDN Q.1-Q.3 Q.4-Q. 59 Q.4-Q. 9 (2.10-Q.11 Q.12-Q.19 (2.204.34 Q.35-a.39 (2.404.47 Q.48-.49 Q.5M.59 Q.60-Q.99 Q.60-Q.67 Q.6-Q.79 1 Sucptementryseryices . Q.8-Q.99
5、 II CLAUSES APPLICABLE TO ITU-T STANDARD SYSTEMS Q.lO-.119 SPECIFICATION OF SIGNALLING SYSTEMS No. 4 AND No. 5 SPECIFICATIONS OF SIGNALLING SYSTEM No. 6 SPECIFICATIONS OF SIGNALLING SYSTEM R1 SPECIFICATIONS OF SIGNALLING SYSTEM R2 DIGITAL EXCHANGES INTERWORKING OF SIGNALLING SYSTEMS SPECIFICATIONS O
6、F SIGNALLING SYSTEM No. 7 DIGITAL SUBSCRIBER SIGNALLING SYSTEM No. 1 PUBLIC LAND MOBILE NETWORK INTERWORKING WITH SATELLITE MOBILE SYSTEMS INTELLIGENT NETWORK BROADBAND ISDN Q.120-Q.249 Q.250-Q.309 (2.31 -Q.399 Q.400-Q.499 Q.500-(2.599 Q.600-Q.699 Q.700-Q .849 Q.850-Q.999 Q.1000-Q.1099 Q.llOO-Q.1199
7、 Q.1200-(2.1999 Q.2000-Q.2999 For further details, please refer to ITU-T List of Recommendations. STD-ITU-T RECMN Q-82J-ENGL L77b qBb2571 Ob2078b ZTU = ITU-T RECOMMENDATION Q.82-7 STAGE 2 DESCRIPTION FOR CALL OFFERING SUPPLEMENTARY SERVICES: EXPLICIT CALL TRANSFER Summary This Recommendation defines
8、 the Stage 2 of the Explicit Call Transfer (ECT) supplementary service. The ECT supplementary service enables a user who has two calls, each of which can be an incoming or an outgoing call, to connect the other users in the two calls. Source RU-T Recommendation 4.82.7 was prepared by ITU-T Study Gro
9、up 11 (1993-1996) and was approved under the WTSC Resolution No. 1 procedure on the 9th of July 1996 . STDOITU-T RECMN Q*82-7-ENGL L77b 48b257L Ob20787 137 FOREWORD ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The lTU Teleco
10、mmunication 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 Telecommunication Standardiz
11、ation Conference (WTSC), which meets every four years, establishes the topics for study by the PU-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 down in WTSC Resolution No. 1 (
12、Helsinki, March 1-12, 1993). In some areas of information technology which fall within EU-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
13、ion administration and a recognized operating agency. O ITU 1996 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. 11 Recommendation Q
14、.82.7 (07/96) STDmITU-T RECMN Q-82-7-ENGL L99b Li8b259L Ob20788 073 9 1 2 3 4 5 6 6.1 6.2 6.3 7 7.1 7.2 8 8.1 8.2 8.3 8.4 8.5 8 -6 9 9.1 9.2 9.3 9.4 9.5 9.6 10 CONTENTS Page Scope Normative references . Definitions . Symbols and abbreviations Description . Derivation of the functional model Function
15、al model description . Description of functional entities . Relationship with a basic service . Information flows . Information flow diagrams . Definition of the individual information flows 7.2.1 Relationship rq 7.2.2 Relationship rr 7.2.3 Relationship rsl 7.2.4 Relationship rs2 7.2.5 Relationship
16、rt . 7.2.6 Relationship ru SDL diagrams for functional entities . FE1 . FE2 . FE3 . FE4 . FE5 . FE6 . Functional Entity Actions (FEAs) FEAs of FE1 FEAs of FE2 FEAs of FE3 FEAs of FE4 FEAs of FE5 FEAs of FE6 Allocation of functional entities to physical locations . 1 1 2 2 2 3 3 4 4 4 4 7 7 7 8 9 10
17、10 11 12 14 15 19 22 25 26 26 26 26 27 27 28 28 . Recommendation Q.82.7 (07196) 111 STD-ITU-T RECMN Q*82*7-ENGL L77b 48b257L Ob20787 TOT Recommendation Q.82.7 STAGE 2 DESCRIPTION FOR CALL OFFERING SUPPLEMENTARY SERVICES: EXPLICIT CALL TRANSFER (Geneva, 1996) 1 Scope This Recommendation defines the S
18、tage 2 of the Explicit Call Transfer (ECT) supplementary service. Stage 2 identifies the functional capabilities and the information flows needed to support the service as described in Stage 1. The Stage 2 description also identifies user operations not directly associated with a call (see Recommend
19、ation 1.130 2). This Recommendation is specified according to the methodology specified in Recommendation Q.65 3. In addition, this Recommendation does not specify the requirements where the service is provided to the user via a private ISDN. This Recommendation does not specify the requirements for
20、 the allocation of defined functional entities within a private ISDN, it does however define which functional entities may be allocated to a private ISDN. This Recommendation does not specify the additional requirements where the service is provided to the user via a telecommunications network that
21、is not an ISDN. The ECT supplementary service enables a user who has two calls, each of which can be an incoming or an outgoing call, to connect the other users in the two calls. The ECT supplementary service is applicable to all circuit-switched telecommunication services. This Recommendation is ap
22、plicable to the Stage 3 Recommendations for the integrated services digital network. 2 Normative references The following Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editi
23、ons 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 of the currently v
24、alid ITU-T Recommendations is regularly published. 13 RU-T Recommendation I. 1 12 (1993), Vocabulary of terms fur ISDNs. 2 CClTT Recommendation I. 130 (1988), Method fur the characterization of telecornmunication services supported by an ISDN and network capabilities of an ISDN. 3 CCITT Recommendati
25、on Q.65 (1988), Stage 2 of the method for the characterization of services supported by an ISDN. 141 RU-T Recommendation 4.7 1 (1 993), ISDN circuit mode switched bearer services. 5 ITU-T Recommendation Z. 100 (1993), CCITT Specijkation and Description Language (SDL). Recommendation 4.82.7 (07196) 1
26、 STD.ITU-T RECMN Q-82-7-ENGL 199b m 48b2591 Ob20791 bb8 3 Definitions For the purposes of this Recommendation, the following definitions apply: 3.1 3.2 3.3 3.4 3.5 calls at user As local exchange. 3.6 the primary and secondary calls. 3.7 3.8 3.9 integrated services digital network (ISDN): See 2.3n.1
27、12 i, definition 308. primary call: One of the user As (answered) calls secondary call: The other user A call (answered or alerting). service; telecommunications service: See 2.2K 1 12 i, definition 201. transfer by join: The effecting of transfer by joining together the primary and secondary transf
28、er by re-routing: The effecting of transfer by establishing a new connection to replace user A: The served user, i.e. the user requesting the ECT supplementary service. user B: The other user in user As primary call. user C: The other user in user As secondary call. 4 Symbols and abbreviations For t
29、he purposes of this Recommendation, the following abbreviations are used. CC Call Control CCA Call Control Agent ECT Explicit Call Transfer FE Functional Entity FEA Functional Entity Action ISDN Integrated Services Digital Network LE Local Exchange PTNX Private Telecommunications Network Exchange SD
30、L Specification and Description Language TE Terminal Equipment 5 Description This Stage 2 supports only one variant of the ECT supplementary service, that of transfer by join. The functional model supports intenvorking with transfer by re-routing, which may occur within a private network but involvi
31、ng users of a public network. Table 1 shows the states for the invocation of the ECT supplementary service, 2 Recommendation Q.82.7 (07/96) TABLE 114.82.7 Primary call Active, idle Secondary call Active, idle Active, held Active, idle Active, idle Active, held Active, idle The procedures are current
32、ly restricted to basic telecommunication services involving a single 64 kbit/s connection. This Recommendation is not applicable to a videotelephony call involving two 64 kbit/s connections. Active, idle (Note 2) Active, held (Note 2) Alerting, idle (Note i) Alerting, idle (Note 1) Alerting, held (N
33、ote 1) 6 Derivation of the functional model I 6.1 Functional model description The functional model for the ECT supplementary service is shown in Figure 1. ru user B N - FE6 FE4 FES FE6 FIGURE UQ.82.7 Functional model for the ECT supplementary service Recommendation Q.82.7 (07196) 3 STD-ITU-T RECMN
34、Q.Z-7-ENGL L77b LiAb257L b20793 430 R 6.2 Description of functional entities The Functional Entities (FES) required by the ECT supplementary service in addition to those of basic call are as follows: FE 1 : Transfer invoke entity; FE4 FE5 FE6 FE2: Transfer validate entity; FE3: Transfer execute enti
35、ty; FE4: Transfer screen entity; FE5: Transfer complete receive entity; FE6: Transfer inform receive entity. cc 6.3 The relationship with a basic service is as shown in Figure 2. Relationship with a basic service CCA rl or FEZ FE3 or r3 N N I or r3 T1175230-95 FIGURE 214.82.7 Relationship with a bas
36、ic service 7 Information flows 7.1 Information flow diagrams The information flow diagrams assume the existence of a primary call and a secondary call and that both calls are maintained until the completion of the transfer. Clearing of the primary and secondary calls with respect to the served user
37、is not shown as this uses basic call information flows only. Similarly any information flows concerned with holding and retrieving the primary and secondary calls are outside the scope of this Recommendation. The TERMINAL DETAILS information flow may occur between both FEs. Where there is no informa
38、tion to be sent at all, the information flow is not present in either direction. The information flow is only shown in one direction in Figure 3 for reasons of clarity. 4 Recommendation Q.82.7 (07/96) STD-ITU-T RECMN Q.82-7-ENGL 377 D The TRANSFER ACTIVE information flow will only occur in the case
39、of an alerting transfer where the alerting user subsequently answers. In such a case, a TERMINAL DETAILS information flow from user Bs FE6 may also occur as a result of receiving the second TRANSFER INFORM indication. rt . - - - - - - RANSFEF INFORM req.ind rs2 . - - - - - - RANSFEF OM PLETI reqhd 9
40、1 - l? 1( 1: rr INVOKE reqhd r RANSFEI INVOKE RANSFER NVOKE r- 9 resp.conf resp.conf TRANSFER COMPLETE reqhd I / 931 932 933 (Note) 934 - 936 937 938 - TRANSFEI 339COMPLET req.ind NOTE - If the optional procedures for preventing loops are provided, the information before proceeding with the rest of
41、the information flow shown in this figure. FIGURE 3/Q.82.7 (sheet 1 of 2) Successful call transfer rs2 -_ RANSFER OMPLETE flow shown in Figure 4 occurs rt . - - - - - RANSFEI INFORM a I I I l l T1175uD85 at this point, Recommendation 4.82.7 (07196) 5 STD-ITU-T RECMN Q-82-7-ENGL 177b LiBb2571 Ob20775
42、 203 I E( 6: 54 - - - 61 62 63 64 “ _) reqhd RANCFER INFORM reqhd rs2 ERMINAI DETAILS req.ind - RANSFEf ACTIVE reqhd TERMINAL DETAILS reqhd I TRANSFER ACTIVE reqhd SETUP :$? i-; I fromFE1 FEA921, Yes I-_ Awaiting confirmation TRANSFER resp.conf I I - -_ I FEA925, I from FE3 I INVOKE to local FE6 I r
43、eqhd I -7- _-_-_-_I -_ A terminal details FEA 956 _I I TERMINAL DETAILS _ FEA 957 to local FE4 _-_-_I FIGURE 914.82.7 (sheet 2 of 3) SDL diagrams for FE5 Recommendation 4.82.7 (07196) 23 STD-ITU-T RECMN Q-82-7-ENGL 177b iBbZ.571 Ob20813 059 FIGURE 9/Q.82.7 (sheet 3 of 3) SDL diagrams for FE5 24 Recommendation Q.82.7 (07/96)
