Link establishment method for call diversion or forwarding in communications network

摘要

The method is applied to a call from a subscriber station (TS-A) in one communication system (KS-A) to a station (TS-B) in another system (KS-B) for which call diversion or forwarding to a station (TS-C) in a third system (KS-C) is in force. The link is set up initially between the second and third systems. The third system then sends a rerouting request to the originating system, which responds by working out an alternative route which bypasses the second system, and authorising the destination system to switch to the alternative route.