Information exchange between the gateway for route optimization by the network-based mobility management

The present invention is, with respect to two access gateway, by notifying the existence and identity of each other in order to establish a data path between them, are located in different network 2 of the mobile node (MN the entire data path on how to reduce the data packets exchanged between). Especially, the access gateway includes an address of the other gateway, the additional, and the address of the other MN to the access gateway transfers the data packet of another MN addressed to another access gateway. The combination of a session initiation protocol message (invite and Ringing) and route optimization messages are used to give information about the ID and address of the MN in a gateway to the respective gateways.