Stage 2 Description for Call Offering Supplementary Services Clause 2 - Call Forwarding Clause 3 - Call Deflection - General Recommendations on Telephone Switching and Signalling - Functions and Information Flows for Services in the ISDN (Study Group XI)
This Recommendation defines the Stage 2 for the Call Forwarding supplementary services (CFB, CFNR, CFU) of Integrated Services Digital Network (ISDN) as provided by public telecommunicationsoperators. Stage 2 identifies the functional capabilitiesand the information flows needed to support the service description.The Stage 2 description also identifiesuser operationsnot directly associated with a call (see Recommendation I.130 [i]).This Recommendation is specifiedaccording to the methodology specifiedin Recommendation Q.65 [2].This Recommendation does not formally describe the relationshipbetween this supplementary service and the basic call,but where possible this information is included for guidance.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 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 is not an ISDN.This Recommendation describes the three versions of Call Forwarding supplementary services, when implemented using the “forward switching” network routing algorithm and partial reroutingat the public/private network interface as contained in Recommendation Q.80 [3].The descriptionof full reroutingas describedin Recommendation Q.80 is outside the scope of this Recommendation.The procedures for the activatioddeactivationkegistrationof the forwarding services are contained in Annex B.The CFU supplementary servicepermits a served user to have the network send to another number all incoming calls for the served user’s number (orjust those associated with a specifiedbasic service).The served user’s originating service is unaffected. If this serviceis activated, calls are forwarded no matter the conditionof the termination.The CFB supplementary servicepermits a served user to have the network send to another number all incoming calls for the served user’s number (or just those associated with a specified basic service) which meet busy at the served user’s ISDN number.The served user’s originating serviceis unaffected.The CFNR supplementary service permits a served user to have the network send to another number all incoming calls for the served user’s number (or just those associated with a specified basic service) which meet no reply at the served user’s ISDN number. The served user’s originating serviceis unaffected.The forwarded-to number is registeredwith the network for use on all calls.