Internet service provider call redirection

摘要

A telephone network constructed according to the present invention includes call redirection functions that redirect calls intended for a toll-free-number or central number of an Internet Service Provider (ISP) to one of a plurality of available Internet Protocol (IP) gateways operated by the ISP. Call redirection may be performed within a coupled signaling network during a database lookup or Service Control Point operation, at a signal switching point of a destination switch or by a PBX operated by the ISP. The call redirection may be static or may be dynamic. In static call redirection, all calls are redirected to a single IP gateway. In dynamic call redirection, one of a plurality of available IP gateways is selected based upon operating conditions. In making such selection, IP gateway loading, IP gateway availability, telephone network loading, telephone network availability and telephone network routing costs are considered. In a first embodiment, a call is received by the telephone network and a number lookup is performed to identify the DN of the destination switch. The call is routed via the signaling network to the destination switch and redirected by the destination switch to a new IP gateway. The call is then completed to the new IP gateway. In a second embodiment, the call is first routed to a PBX operated by the ISP and the PBX redirects the call to a new IP gateway. In a third embodiment, the signaling network itself redirects the call to a new IP gateway.