Communications call routing
OwnerAnthony david Wilsoninventor
Life of this patent
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Abstract
A method and corresponding apparatus, programs, and signals for maximising the use of trunks between telecommunications network nodes (for example Private Branch Exchanges (PBX's)) whilst avoiding looping during call set-up phase. Looping avoidance is achieved by including in the call set-up request messages a trail log comprising indications of those nodes through which the call set-up message has already passed. Each node in the network can then forward the call set-up sequence for a new voice call dependent both on the local routing tables stored in each routing node and the list of previously passed nodes contained in the call set-up message, and in particular avoiding routing a received call set-up message back to a node indicated in the trail log of that set-up message.
Claims16
A method of routing calls in a telecommunications network routing node, the method comprising the steps of:
- receiving a call set-up request comprising an indication of at least one node through which the set-up request has passed;
- retrieving previously stored call routing information;
- routing the call set-up request responsive to a comparison between the indication and the previously stored call routing information.
A call routing node, for a telecommunications network, comprising:
- a port arranged to receive a call set-up request comprising a trail log, from another call routing node;
- a store for storing call routing information;
- a router arranged to route the call set-up request responsive to a comparison between the trail log and the stored call routing information.
A program for a computer in a machine readable form for routing calls in a telecommunications network comprising a plurality of nodes, the program comprising portions arranged to perform the steps of:
- receiving a call set-up request comprising a trail log;
- retrieving previously stored call routing information;
- routing the call set-up request responsive to a comparison between the trail log and the previously stored call routing information.
A telecommunications signal comprising a call set-up request comprising a trail log for use in routing the call set-up request.
Dependencies are inferred from the claim text.