Patent ID: 7133500

Claim:
A method of intercepting calls for a subject under surveillance (SUS) in a Signaling System 7 (SS7) Intelligent Network (IN) compliant telephone system, wherein the SUS has an assigned first telephone number that others use to call the SUS on a SUS subscriber line, the method comprising: assigning to the SUS a surveillance telephone number for surveillance purposes, wherein both the first telephone number and the assigned surveillance telephone number are used to route telephone calls to the SUS, and wherein the surveillance telephone number and the first telephone number for the SUS are different; in an end office switch, configuring the identity of a line card for the SUS to the surveillance telephone number so that calls placed by the SUS identify the SUS as a calling party by the surveillance telephone number; configuring a routing table of the end office switch so that the calls placed by the SUS to a called party telephone number are forwarded to a delivery function unit, and so that calls placed to the SUS using the first telephone number are forwarded to the delivery function unit; the delivery function unit receiving the forwarded calls, and identifying the SUS by the surveillance telephone number as the calling party or by the first telephone number as a called party; the delivery function unit forwarding calls placed by the SUS back to the end office switch with the calling party identified with the SUS's first telephone number and with the called party telephone number provided by the SUS so that the end office switch forwards calls placed by the SUS to the called party, and forwarding calls placed to the SUS to the end office switch with the surveillance telephone number as the called party telephone number and with the calling party telephone number the same as received from the end office switch so that calls placed to the SUS are connected to the SUS's subscriber line; and the delivery function unit further obtaining a copy of call content for any calls forwarded through the delivery function unit.