Patent ID: 7372861

Claim:
An access control apparatus which controls connection to a public network via a service provider terminal from a plurality of user terminals manipulated by unspecified users, comprising: means for holding a predetermined number of addresses provided in advance by the service provider terminal and converting two addresses into each other: an address capable of specifying an arbitrary apparatus on the public network and a unique address under control of said means for holding a predetermined number of addresses; means for issuing IDs for specifying users of the user terminals; means receiving addresses, assigned by the service provider terminal, transferred by the means for holding a predetermined number of addresses for managing these addresses; means for, upon reception of a connection request from one of the user terminals, determining whether a logical address has already been assigned to the requesting user terminal; means for assigning a logical address for which a time limit is set, to a user terminal not assigned any logical address; means for, in response to a connection request from the user terminal assigned the logical address, requesting the user terminal serving as a transmission source of the connection request to transmit the ID; means for determining, on the basis of the ID acquired from the user terminal serving as the transmission source of the connection request, a user and a used user terminal by which the connection request to the public network has been transmitted; means for connecting the user terminal to the public network when a use time of the logical address assigned to the user terminal serving as the transmission source of the connection request falls within the time limit set for the logical address; and means for disconnecting the user terminal from the public network when the use time of the logical address assigned to the user terminal connected to the public network reaches the time limit set for the logical address.