An apparatus for retrieving at least one of an access network or core network assigned user equipment identifier (NGAP ID) from outside of the access or core network using IP addressing information. The apparatus configured to receive IP addressing information of the user equipment; determine a subscriber permanent user identity for the user equipment from the IP addressing information; generate and transmit a request for the at least one of the access network or core network assigned user equipment identifier, the request including the subscriber permanent identity; and receive the at least one of the access network or core network assigned user equipment identifier.