A networking system comprises a proxy mobility agent (PMA) module, and a home agent (HA) module. The PMA module sends a first binding update message including a unique identifier to a remote HA based on a trigger signal. The unique identifier identifies a mobile terminal associated with the remote PMA. The HA module receives a second binding update message including the unique identifier from a remote PMA, and selectively sends the trigger signal to the PMA module based on the second binding update message.