Patent ID: 8520609

Claim:
A method for providing an interface between a visited network that supports the Simple Internet Protocol (SIP) and a home network that supports the Mobile Internet Protocol (MIP), the method comprising: by an interoperability and interworking function (IIF) module: determining that a mobile station, visiting the visited network or the visited network does not support MIP; upon determining that at least one of the mobile station, visiting the visited network, and the visited network does not support MIP, establishing a SIP compatible tunnel, between an access gateway process in the visited network and a Proxy Mobile Gateway of the IIF, and a MIP compatible tunnel between a Home Agent (HA) in the home network and a Proxy Foreign Agent of the IIF; and transmitting, over one of the SIP compatible tunnel and the MIP compatible tunnel using data packet encapsulation, data packets received at the IIF over the other tunnel.