Patent ID: 8433289

Claim:
A communication apparatus used in a radio access network to relay data transmission to and from a remote network, the communication apparatus comprising: a monitoring unit configured to monitor an authentication procedure performed when a mobile station makes a connection of a link to the remote network, as well as when the mobile station disconnects the link to the remote network; a producing unit configured to produce information for disconnecting a session of the mobile station based on progress of the authentication procedure monitored by the monitoring unit; a translation table to translate address information of the mobile station; a filtering table to store the address information that is transferred from the translation table when the mobile station is deauthenticated in response to disconnection of the link of the mobile station; and an allocation unit, responsive to completion of the authentication procedure of the mobile station which is performed when the mobile station makes a connection of a link, to select address information that is different from the address information stored in the filtering table and allocate the selected address information to the mobile station, as well as entering the selected address information in the translation table.