A mobile Internet Protocol service provider system implements home agent functionality in two separate devices. One device, the home registration agent, is devoted to registration of the mobile node and session control. The other device, the home tunneling agent, is devoted to tunneling and routing functions for the foreign agent. The home registration agent can be a general purpose computer. The home tunneling agent is preferably implemented in a robust routing device, such as an IP switch or router. Multiple home tunneling agents or home registration agents can be implemented in the respective devices as multiple instantiations of a home registration agent or home tunneling agent software program.Foreign agent functionality for mobile IP networking can also be split into separate devices. In a preferred embodiment, a foreign registration agent handles session control and registration traffic with the home registration agent, and a foreign tunneling agent provides packet capsulation/decapsulation and routing services for the mobile node and exchanging data traffic with the home tunneling agent.