Patent ID: 7286520

Claim:
Mobile terminal equipment having a packet communication function and a communication route optimizing function according to a mobile IP (Internet Protocol), comprising a session controller for setting a session between terminals in accordance with a session control message of a protocol different from the mobile IP, the session controller having: means for deciding, after a session control message from the other party is received in a visited network apart from a home network of the mobile IP and before beginning transmitting a data packet, whether an optimization of a communication route to the other party by said communication route optimizing function is necessary or not according to the session control message, and means for executing optimization of said communication route to the other party by said communication route optimizing function if the optimization of a communication route to the other party is decided as necessary, before sending a response message for the session control message, wherein the packet communication function transmits said data packet only after completing optimization of said communication route and only through said optimized communication route.