Authentication in an IP multimedia subsystem network where an in-use line identifier (LID) does not match a registered LID

摘要

A method and telecommunication node for authenticating with an IP Multimedia Subsystem (IMS) network, a nomadic user in an access network. The node receives from the access network, an access identifier defining a mobile terminal's physical location. In response, the node retrieves from a database, a registered access identifier associated with the user and determines whether the received identifier matches the registered identifier. If the identifiers match, the node authenticates the user in the IMS network. If the identifiers do not match, the node performs an alternate authentication method.