Advanced intelligent network (ain) functionality for electronic

Abstract

Following the Communications Assistance for Law Enforcement Act (CALEA), the FBI developed a standard set of communication services and interfaces for lawfully authorized electronic surveillance. For telephone communications, the current industry implementation of compliance with this standard involves deploying certain interface equipment in end office switches of the telephone network. However, the requisite surveillance functionality often resides in a certain limited number of offices. Where the target under surveillance receives service out of an office lacking the surveillance capability, the network routes the call through an office having the requisite capability. For this purpose, the invention relies on intelligent network processing, particularly variations on such processing normally used to implement local number portability. The control node supplying the routing information for local number portability also supplies routing information for surveillance related calls, in order to route calls to and from the target location through an office having the surveillance interfaces in a manner that is entirely hidden from the target and anyone communicating with the target.