To provide a roaming service system and accounting server that can provide a service for a speech from a mobile phone at a fast communication speed and simplify the accounting processing, and to provide, a router, an authentication server, a clearance server, a telephone directory server and computer software.

The roaming service system provided with a cable television network 2, a router 3 that connects with a public telephone network 62, and a accounting server 4 is provided with an access point device 1 receiving a subscription request from a mobile phone. The accounting server 4 has a function of requesting an authentication confirmation to an authentication server 51 and a function of receiving an authentication result notice from the authentication server 51.