1、INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMM U N CATION STAN DARD IZATION SECTOR OF ITU DIGITAL SUBSCRIBER SIGNALLING SYSTEM No. 1 Q.952 (03/93) STAGE 3 SERVICE DESCRIPTION FOR CALL OFFERING SUPPLEMENTARY SUPPLEMENTARY SERVICES SERVICES USING DSS 1 - DIVERSION ITU-T Recommendation Q.952 (Pre
2、viously “CCIlT Recommendation”) ITU-T RECMN*Q.752 73 4862573 0590758 884 FOREWORD The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the International Telecom- munication Union. The ITU-T is responsible for studying technical, operating and tariff questions and issuing
3、Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Conference (WTSC), which meets every four years, established the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these
4、 topics. ITU-T Recommendation Q.952 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 reform process within the International Telecommunication Union (ITU), the CC ceased to exist as of 28 February 1993. In i
5、ts 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 Similarly, in this reform process, the CCIR and the IFRB have been replaced by the Radiocommunication Sector, In order not to delay publication of this Recommendation, no change has been made in the te
6、xt to references containing the acronyms “CCITT, CCIR or IFRB” or their associated entities such as Plenary Assembly, Secretariat, etc. Future editions of this Recommendation will contain the proper terminology related to the new ITU structure. 2 telecommunication administration and a recognized ope
7、rating agency. In this Recommendation, the expression “Administration” is used for conciseness to indicate both a O ITU 1994 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, wit
8、hout permission in writing from the ITU. ITU-T RECMN*Q.952 93 m 4862593 0590759 730 m CONTENTS 1 Definition . 2 Description . 4 Coding requirements 5 Signalling procedures at the coincident S and T reference point . 6 Interaction with other supplementary services . 7 Interactions with other networks
9、 8 Signalling flows . 9 Parameter values (timer) 3 Operational requirements . 10 Dynamic description (SDLS) . Annex A References . Recommendation Q.952 (03/93) Page 1 2 4 6 8 24 26 29 37 37 65 65 I Recommendation Q.952 STAGE 3 SERVICE DESCRIPTION FOR CALL OFFERING DIVERSION SUPPLEMENTARY SERVICES SU
10、PPLEMENTARY SERVICES USING DSS 1 - (Helsinki, 1993) The stage 3 services described below correspond to those of stage 1 which appeared in the I-Series Recommendations as follows: - - - - Call Forwarding Unconditional (CFU): Recommendation 1.252.4 Call Forwarding Busy (CFB): Recommendation 1.252.2 Ca
11、li Forwarding No Reply (CFNR): Recommendation 1.252.3 Call Deflection (CD): Recommendation 1.252.5 1 Definition 1.1 Scope This Recommendation specifies the stage 3 of the diversion supplementary services for the Integrated Services Digital Network (ISDN) as provided by public telecommunications oper
12、ators at the T reference point or coincident S and T reference point (as defined in Recommendation 1.41 1 I) by means of the Digital Subscriber Signalling System No. 1 (DSS 1). Stage 3 identifies the protocol procedures and switching functions needed to support a telecommunications service (see Reco
13、mmendation 1.130 2). In addition, this Recommendation specifies the protocol requirements at the T reference point where the service is provided to the user via an intermediate private ISDN. This Recommendation does not specify the additional protocol requirements where the service is provided to th
14、e user via a telecommunications network that is not an ISDN. The diversion supplementary services comprise the following services: - Call Forwarding Unconditional (CFU) - Call Forwarding Busy (CFE3) - - Call Deflection (CD) Call Forwarding No Reply (CFNR) The Cali Forwarding Unconditional (CFU) supp
15、lementary service permits a served user to have the network send all incoming calls, or just those associated with a specific basic service, addressed to the served users ISDN number to another number. The served users originating service is unaffected. If this service is activated, calls are forwar
16、ded no matter what the condition of the termination. The Call Forwarding Busy (CFB) supplementary service permits a served user to have the network send all incoming calls, or just those associated with a specific basic service, which meet busy and are addressed to the served users ISDN number to an
17、other number. The served mers originating service is unaffected. The busy condition may be either network determined or user determined. The Call Forwarding No Reply (CFNR) supplementary service permits a served user to have the network send all incoming calls, or just those associated with a specif
18、ic basic service, which meet no reply and are addressed to the served users ISDN number to another number. The served users originating service is unaffected. The Call Deflection (CD) supplementary service allows the served user to respond to an incoming call offered by the network by requesting red
19、irection of that call to another number specified in the response. This redirection is only allowed before the called user has answered the call. The served users originating service is unaffected. Recommendation Q.952 (03/93) 1 ITU-T RECMNtQ.952 93 m 48b2591 05907bL 379 m The diversion supplementar
20、y services are applicable to all telecommunications services. Further subclauses of this Recommendation specify the method of testing required to identify conformance to this Recommendation. Annex A provides the ASN. 1 definition of basic services in call fowarding supplementary service procedures.
21、This Recommendation is applicable to equipment, supporting at least one of the diversion supplementary services, to be attached at either side of a T reference point or coincident S and T reference point when used as an access to the public ISDN. 2 Description 2.1 General description For a given ISD
22、N number, the diversion supplementary services (including options) may be subscribed to for each basic service to which the user(s) of the number subscribes, or collectively for all the bearer service or/and teleservice to which the user(s) subscribes. Since subscription is on an ISDN number basis,
23、the same diversion subscriptions will apply to all terminals using this number. The served user can request a different forwarded-to number for each basic service subscription parameter value and diversion supplementary service to which he has subscribed. An indication that a call forwarding service
24、 is activated on a number may, as subscription option, be given to the forwarding user who has forwarding activated, each time an outgoing call is made. The CFNR supplementary service shall only apply when a SETUP message is sent by the network and at least one user responds with an ALERTING message
25、, possibly subsequent to other valid call control message. The deflection functions are implemented in the network and they are invoked by the terminai on a call by call basis. 2.2 Definitions For the purposes of this Recommendation, the following definitions apply: integrated services digital netwo
26、rk (ISDN): See 2.3h.112 5, definition 308. service; telecommunications service: See 2.2h.112 5, definition 201. supplementary service: See 2.4A.210 171. user: The DSS 1 protocol entity at the user side of the user-network interface. network: The DSS 1 protocol entity at the network side of the user
27、network interface. served user: The DSS 1 protocol entity at the user side of the user-network interface used to subscribe to the specific diversion supplementary service; to register, to activate, to deactivate and the interrogate diversion supplementary services; to request and to control the dive
28、rsion supplementary services. forwarded-to user: is a user to which a call is to be forwarded. All procedures at the forwarded-to user are provided as part of the basic service; the forwarded-to user need not have subscribed to any specific call forwarding supplementary service. deflected-to user: i
29、s a user to which the call shall be deflected. diverted-to user: Refere either to the forwarded-to user or the deflected-to user. calling user: is a user that initiated a call that has been diverted. All procedures at the calling user are provided as part of the basic service; the calling user need
30、not have subscribed to any specific diversion supplementary service. diverted-to number: is the ISDN number of the forwarded-to/deflected-to user. forwarded-to number: is the ISDN number of the forwarded-to user. deflected-to number: is the ISDN number of the deflected-to user. 2 Recommendation Q.95
31、2 (03/93) diverting number: is the ISDN number of the forwarding/deflecting user. forwarding number: is the ISDN number of the forwarding user. deflecting number: is the ISDN number of the deflecting user. activating user: is a user on a served users access that initiates the activation procedures f
32、or a call forwarding service. deactivating user: is a user on a served users access that initiates the deactivation procedures for a call forwarding service. caii forwarding profde: is the set of data containing all the parameters pertaining to subscription and activation, involved in the decision p
33、rocess which leads to the forwarding of an incoming call. ISDN number: a number conforming to the numbering plan and structure specified in Recommendation E.164 14. ISDN address: it is an ISDN number, and uses a sub-address, as specified if provided by that. network determined user busy (NDUB): See
34、3.1.4A.210 17. user determined user busy (UDUB): is specified for the case that the network offers the call to the subscriber and if no compatible terminal responds “positively” but one or more compatible terminal respond “user busy”. This condition will be determined when the response-to-call offer
35、ing timeout occurs. invoke component: See Recommendation 4.932 4. return result component: See Recommendation 4.932 4. return error component: See Recommendation 4.932 4. reject component: See Recommendation 4.932 4. 2.3 Abbreviations ISDN Integrated Services Digital Network DSS 1 CFU Call Forwardin
36、g Unconditional CFB Call Forwarding Busy CFNR Call Forwarding No Reply CD Call Deflection CDA Call Deflection Alerting UDUB User Determined User Busy NDUB Network Determined User Busy ISPBX ISDN PABX Digital Subscriber Signalling System No. 1 2.4 State definitions The following states are conceived
37、for the call forwarding supplementary service management procedures at the served users access and are applicable to the network and optionally the user: Idle srciCe - The specific call forwarding supplementary service is idle for this ISDN number and/or particular basic service. This is the initial
38、 state on subscription of the particular call forwarding supplementary service. Activate Request srafe - The user has requested that a supplementary service is activated for this ISDN number and/or particular basic service. Deactivate Request sture - The user has requested that an active supplementa
39、ry service shall be deactivated for this ISDN number and/or particular basic service. Interrogate Request state - The user has requested that a supplementary service be interrogated. - - - - Recommendation Q.952 (OY93) 3 ITU-T RECMN*Q.952 93 4862593 0590763 141 M Subscription options Allowable defle
40、cted to user numbers A state machine may exist for each specific instance of the following parameter values: - procedure; - served user number; - basic service. Value Applicability All 3 Operational requirements Calls which may be deflected 3.1 Provision/withdrawai Others (for furthtr study) CD All
41、The CFU, CFB, CFNR and CD supplementary sen .:es shall be provided after prior arrangement with the network. Each diversion supplementary service can be withdrawn separately by the network at the subscribers request or for administrative reasons. The diversion supplementary services can be offered s
42、eparately with subscription options. Options apply separately to each bearer service odand teleservice subscribed to on each ISDN number. For each subscription option, only one value can be selected. These subscription options form part of the diversion profile for the served user. The subscription
43、options for the CFU supplementary service are included in 3.1A.252.4 7. The subscription options for the CFB supplementary service are included in 3.1n.252.2 8. The subscription options for the CFNR supplementary service are included in 3.1A.252.3 9. The subscription options for the CD supplementary
44、 service are included in 3.1K252.5 IO. These requirements are summarized in Table 1. Others (for further study) TABLE VQ.952 Subscription options for diversion supplementary services CD Served user receives notification that a call has been forwarded CFU CFB CFNR No Yes, with call offering informati
45、on Calling user receives notification that his call that his call has been diverted (forwarded or deflected) CFU No Yes. with diverted-to number CFB Yes, without diverted-to number CFNR CD I No Served user receives reminder notification on outgoing Yes I CFNR calls that forwarding is currently activ
46、ated Diverting number is released to diverted-to-user I Do not release diverting number information I Release diverting number information CFNR I CD 5 to 60 seconds in steps of 5 seconds Length of call forwarding on no reply timer 4 Recommendation Q.952 (03/93) ITU-T RECMN*d.952 93 48b259L 0590764 0
47、88 iii) Served user call retention when deflection is rejected The following network provider options are available for the supplementary services. The network options for the CFU supplementary service are included in 3.3.2A.252.4 7. The network options for the CFB supplementary service are included
48、 in 3.3.20.252.2 8. The network options for the CFNR supplementary service are included in 3.3.2I.252.3 9. The network options for the CD supplementary service are included in 3.2.uI.252.5 and 3.3.3fl.252.5 IO. These requirements are summarized in Table 2. Continue the call, this option shall be use
49、d for deflection after alerting has commenced Clear the call 3.2 The procedures at the coincident S and T reference point of 5.UQ.931 3 and the notification procedures of 5.2.1 and 5.2.2 shall be applied. Requirements on the originating network side: Call forwarding on no reply timer Partial rerouting Notification to calling user 3.3 The procedures at the S and T reference point of 5.UQ.931 3, the common element procedures of 5.2.3 and the notification procedures of 5.2.4 shall be applied. Requirements on the destinati
