Abstract: A method and apparatus 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) includes establishing a SIP compatible tunnel between an access gateway process in the visited network and a Proxy Mobile Node of a local process. An MIP compatible tunnel is established between a Home Agent (HA) in the home network and a Proxy Foreign Agent of the local process. Data packets received at the local process over one tunnel are transmitted over the other using data packet encapsulation.