Patent ID: 8776184

Claim:
A method for accessing a visited network, comprising: receiving, by an authentication, authorization and accounting (AAA) server device, an access request initiated by a user for selecting a visited network; detecting, by the AAA server device, whether the visited network selected by the user has changed; if the visited network selected by the user has changed, requesting, by the AAA server device, a home subscriber server (HSS) to check whether the user is authorized to access the visited network according to a list of authorized visited networks; and if the user is authorized to access the visited network, returning, by the AAA server device, an access accept response to the user to allow the user to access the visited network; if the visited network selected by the user has not changed, checking, by the AAA server device, whether the user is valid and authorized to access the visited network; and if the user is valid and authorized to access the visited network, returning, by the AAA server device, the access accept response to the user; checking, by the AAA server device, that the user is valid in response to a request sent from the user for updating the list of authorized visited networks according to a preset period; and sending, by the AAA server device, the list of authorized visited networks, which is stored in the AAA server device or obtained from the HSS, to the user.