US Patent 7016343 PSTN call routing control features applied to a VoIP

A system and method of sending and receiving voice calls over the Internet is described. The system includes a PSTN-derived intelligent call routing engine that receives call control messages from the Voice over IP (VoIP) network and routes calls via previously stored, customized routing procedures. Special dialing plan, 800 numbers, minimized cost routing, time and day-based least cost routing, transferring, conferencing, and additional messaging capabilities are provided. The system operates on standard server computers with interface cards connected to the packetized networks via TCP/IP and, indirectly, to VoIP gateways to accessing PSTN networks and to virtual and/or private networks (PBXs).