Patent ID: 8875238

Claim:
An authentication server that is connected to a plurality of connection devices that connect a communication terminal and a network, that authenticates said communication terminal, and assigns one of said plurality of connection devices as a connection device that connects said communication terminal and said network if the authentication is successful, said authentication server comprising: a storage section that stores a preset threshold; a traffic management table that manages traffic data with respect to each said connection device, said traffic data representing a traffic amount, with respect to said connection device, that is contained in a charging information notification signal that provides notification of charging information transmitted from said connection device, the charging information notification signal comprising current charging rate information transmitted from a charging rate server, the current charging rate information comprising the traffic data; a comparison section that compares said traffic data, with respect to each said connection device, with the threshold stored in said storage section and writes the compared result as assignment validity/invalidity information to said storage section, wherein the traffic data is compared with the threshold; and an HA assignment section that reads the assignment validity/invalidity information from said storage section and assigns a connection device other than connection devices whose assignment validity/invalidity information is invalid as a given connection device that connects said connection terminal and said network, wherein the HA assignment section of the authentication server assigns the given connection device based on a result of the comparison made by the comparison section between the traffic data and the threshold, wherein the charging information includes the traffic data, wherein the given connection device is assigned based on a comparison result resulting from comparison of the traffic data and the threshold, wherein if said traffic data are equal to or greater than said threshold, said comparison section writes said assignment validity/invalidity information that is caused to be invalid to said storage section, and wherein if said traffic data are smaller than said threshold, said comparison section writes said assignment validity/invalidity information that is caused to be valid to said storage section.