System, device and method for moving a communication session between network nodes by means of a communication mediator

摘要

An object is to ensure reachability of data even with movement of a session between communication nodes. A home node HN-1 generates a home session address HSA-1 and establishes a session with communication correspondent 90. On the occasion of movement of the session, the home node HN-1 notifies a foreign node FN-1 that it desires to move the session to the foreign node FN-1. The foreign node FN-1 internally generates an IP address HSA-1, copies a state of the session in the home node HN-1, and thereafter notifies a communication mediator node 1 of correspondence update information "HSA-1->HNA-2" in order to let the communication mediator node 1 pass data addressed to HSA-1 to a home node identification address HNA-2 by tunneling. The communication mediator node 1 passes the data to HNA-2 by tunneling on the basis of the correspondence update information and another communication mediator node 2 again passes the data to a care-of address CoA-2 by tunneling.