Patent ID: 8861380

Claim:
An IP telephone terminal that meditates a connection between an external terminal used by a user and a network and that offers a user-specific IP telephone function to the user when address information of the user is registered with a server apparatus connected by way of the network, the IP telephone terminal comprising: a transferring unit that transfers a message received from the external terminal or the network to a destination address designated in the received message; a first judging unit that monitors messages transferred between the external terminal and the network by way of the transferring unit and that judges whether an authentication message, that is used for authentication of the user of the external terminal and includes identification information of the user, is transferred from the external terminal to the network by way of the transferring unit; an identification information acquiring unit that acquires the identification information from the authentication message when the authentication message is transferred by way of the transferring unit; a second judging unit that monitors messages transferred between the external terminal and the network by way of the transferring unit and that judges whether a grant message indicating that the user is authenticated is transferred from the network to the external terminal by way of the transferring unit; a message processing unit that, when the second judging unit determines that the grant message is transferred to the external terminal by way of the transferring unit, creates a registration message including the address information of the user having the acquired identification information and transmits the registration message to the server apparatus; and an IP telephone function enabling unit that enables the user to use the user-specific IP telephone function when receiving, from the server apparatus, an acknowledgement message of the registration message created by the message processing unit.