Information service communication network system and session management server

A session management server, which is provided with a service determination table having a plurality of entries each indicating a service identifier in association with possible particular items of information which may be extracted from a session setup request packet, receives a session setup request packet issued from a client to a particular application server and determines whether the client terminal is authorized to receive an information service by referring to the determination table, in place of the particular application server. When the determination results in success, the session setup request packet is forwarded to the particular application server.