A general global gateway (GGG) internetworks between a first network and a second network so that a mobile station having a subscription in a first network can roam into a second network and be authenticated to use the second network. The GGG obtains authentication parameters from the mobile station and determines whether the authentication parameters satisfy GGG authentication criteria. If it does, then the GGG accesses the first network and stores authentication information from the first network for subsequent accesses to the first network by the mobile station.