statistics of the received accounting information for each mobile station referring to the flowchart of fig4 a web redirect authentication method in the communication system 100 for managing wifi roaming according to an exemplary embodiment will be described in detail first when in the same subnet the user of the mobile station 110 desires to use a wireless internet service in an area where the wireless ap 120 has been installed the mobile station 110 transmits an association request message to the ap 120 in operation s 110 and the ap 120 transfers the association request message to the ac 150 in operation s 111 the association request message includes the mac address of the mobile station 110 and may further include parameters required for a request for a wireless internet service such as the mac address of the destination such as the ap 120 accordingly the authenticator 151 of the ac 150 determines whether roaming service is available whether an association has already been allowed for the mobile station 110 using the mac address and assigns an ip address if there is no assigned ip address in operation s 120 next the authenticator 151 performs the authentication of the corresponding mobile station e g mac address authentication through communication with the authentication server 140.