Patent ID: 7529232

Claim:
A system for telephone communication, comprising: an IP-LAN including an IP telephony server; a dual-mode communication device comprising first communication interface for conducting telephone calls on a cell-phone network, including a cell-phone number, and second communication interface for conducting telephone calls over the IP-LAN; a publicly-switched telephone network (PSTN) having a trunk connection to the IP telephony server; and the PSTN-connected routing server hosted by the cell-phone network; wherein the IP telephony server, upon connection of the dual-mode communication device to the IP-LAN, assigns a temporary IP address to the connected device and informs the routing server of the connection and a destination address for the IP telephony server, and wherein the routing server then routes calls for the cell phone number to the IP telephony sewer, which in turn routes the calls on the IP-LAN to the temporary IP address.