Patent ID: 8588388

Claim:
A telephone system comprising: a plurality of telephone terminals; a first server apparatus configured to register the telephone terminals; and a second server apparatus configured to function as a standby system for the first server apparatus, the first server apparatus comprising a license memory configured to store a terminal ID in association with a license authentication code, wherein the terminal ID corresponds with the telephone terminal, wherein the license authentication code is code for permitting the use of at least one of a plurality of functions or a plurality of hardware circuits or for expanding a capacity, wherein the plurality of functions or a plurality of hardware circuits are concerned with exchange processing between the telephone terminals; a license setting module configured to set a corresponding function or hardware circuit to be usable/unusable in the telephone terminal based on the license authentication code stored in the license memory, a license authentication module configured to perform license authentication by comparing a terminal ID included in a registration request with a terminal ID stored in the license memory when the registration request is transmitted from any one of the telephone terminals, and a transmission controller configured to read from the license memory a license authentication code corresponding to a telephone terminal whose terminal ID coincides with that stored in the license memory, and transmit to the telephone terminal a license authentication code added check information, wherein the check information is information for checking that the code is valid, and the telephone terminal comprising an authentication code memory configured to store check information and a license authentication code sent from the first server apparatus, and a server switching controller configured to transmit to the second server apparatus a registration request and a license authentication code and check information stored in the authentication code memory when a failure has occurred in the first server apparatus in which the telephone terminal is registered, and the second server apparatus comprising a registration controller configured to store in a management table the terminal ID in association with the license authentication code or reject the storing in the management table the terminal ID in association with the license authentication code based on the check information added to the license authentication code sent from the telephone terminal when the telephone terminal send a registration request, and a service controller configured to set a corresponding function or hardware circuit usable/unusable in the telephone terminal to use the corresponding function or hardware circuit continuously for the first server apparatus, based on a license authentication code stored in the management table.