US Patent 7525987 Changing a first subscriber identifier to a second identifier

The invention relates to telecommunications systems, in which a subscriber is identified in a network with a first identifier and with a second identifier in a server providing services to the subscriber through the network. In the invention, the first identifier is changed (3-3) in a message to be transferred to the server to a second identifier before transferring the message to the server. Thus the message received from the network can be associated with a particular subscriber in the server.