Patent ID: 7388850

Claim:
A communication system comprising: a plurality of communication nodes; a communication correspondent in communication with one communication node selected from the plurality of communication nodes; a communication mediator node configured to mediate communication and implement movement of a session between source and destination communication nodes, each source communication node of said plurality of communication nodes comprising: a session managing unit configured to allocate a session identification address for identifying a session at the time of starting communication, and configured to manage an association of the session identification address to each session; a movement notifying unit configured to notify, on the occasion of movement of the session, a destination communication node of movement of the session, each destination communication node of said plurality of communication nodes comprising: a first update notifying unit configured to open a communication session using the session identification address corresponding to the moved session when notified of movement of a session by the source communication node and to notify said communication mediator node of the moved session using session destination correspondence information that includes information regarding a correspondence between the session identification address and a node identification address of the destination communication node, and said communication mediator node comprising: a first managing unit configured to manage the session destination correspondence information and to update the session destination correspondence information based on the notification by the movement notifying unit; and a first tunneling unit configured to encapsulate data and transfer the encapsulated data to the new session identification address of the moved session, on the basis of the updated session destination correspondence information.