Integrated Services Digital Network (ISDN) – Call Deflection Supplementary Service
|Publication Date:||1 June 2014|
Scope & Purpose
This standard is one of a series that defines and describes supplementary services within the context of an Integrated Services Digital Network (ISDN). The interaction of this service with other ISDN services is also included. The purpose of the standard is to allow maximum compatibility among network- and user-owned telecommunication equipment in order to increase the attractive- ness and usefulness of ISDN-based capabilities.
This standard describes the Call Deflection (CD) service in terms of service definition, protocol, and procedures needed for implementation. CD permits a served user to request, in real time, that the network redirect an incoming call addressed to the served user's ISDN number to another number (the deflected-to number). The served user sends the network a deflection request with the deflected-to number provided in the request. The served user's originating service is unaffected.
Unlike ISDN Call Forwarding, the network will redirect a call only after receipt of a specific user request to deflect that call.
The CD capability is applicable to both the Basic and Primary Rate ISDN Interfaces. It is intended to supplement the basic Circuit Mode Bearer Service contained in American National Standard for Telecommunications - Integrated services digital network (ISDN) - Circuit mode bearer service category description, ATIS-1000620. It should be used in conjunction with other American National Standards for ISDN supplementary service for complete understanding of the interactions between this and other services.
This supplementary service is applicable to the following circuit-mode bearer services:
- 3.1-kHz audio;
- 64-kbit/s unrestricted digital information;
- multi-rate (n × 64 kbit/s).