Patent ID: 8775642

Claim:
A method for managing user terminal identification information in a communications system, wherein in response to receiving, in a network apparatus, an invitation message to establish communication between user terminals, the method comprises: examining a first communication address identification of a user terminal included in the invitation message, the examining comprising: retrieving, based on the first communication address identification, a first communication number identification maintained for a corresponding user terminal; based on the retrieved first communication number identification, retrieving a second communication number identification maintained for the user terminal; and checking whether the first communication number identification and the second communication number identification correspond to each other; and wherein based on a result of said checking, the method further comprises: retrieving a second communication address identification corresponding to the second communication number identification; and forwarding the invitation message toward a recipient such that the second communication address identification is included in the invitation message; and updating in the invitation message, if needed, at least one of a communication address identification of an A subscriber and a communication address identification of a B subscriber.