Patent ID: 8161523

Claim:
A network access control (NAC) method for roaming services applicable to a local network comprising at least a local authentication server, a local security policy server, and a local access device, the method comprising: authenticating a roaming terminal by the local authentication server, the local authentication server instructing the local access device to apply a roaming quarantine access policy to the roaming terminal after the roaming terminal is authenticated; applying, by the local access device, the roaming quarantine access policy according to the instruction; executing a security check on the roaming terminal carried out by the local security policy server, the local security policy server instructing the local access device to apply a roaming secure access policy to the roaming terminal after the roaming terminals passes the security check; and applying, by the local access device, the roaming secure access policy according to the instruction; wherein authenticating the roaming terminal further comprises: the local authentication server receiving an authentication request from an access terminal, determining that the access terminal is a roaming terminal, and forwarding the authentication request to a separate home authentication server for processing; and after an “authentication passed” message is returned from the separate home authentication server, instructing the local access device to apply the roaming quarantine access policy to the roaming terminal by the local authentication server replacing a home quarantine access policy ID carried in the “authentication passed” message sent by the home authentication server with a local quarantine access policy ID before sending the message to the local access device.