Patent ID: 8520664

Claim:
An internet protocol multimedia subsystem comprising: at least one first home subscriber server comprising at least one hardware component; at least one call session controlling function for interacting with said at least one first home subscriber server; wherein: the internet protocol multimedia subsystem at least interacts with at least one application server; the internet protocol subsystem further comprises at least one apparatus interposed between a source and a destination respectively being one of: a) at least one among said at least one call session controlling function and said at least one application server, and b) said at least one first home subscriber server; the at least one apparatus is configured for performing adaptation of signaling messages coming from said source and directed to said destination by changing at least one parameter carried by said signaling messages to convert said signaling messages into equivalent signaling messages manageable by said destination; and the at least one apparatus is further configured for routing said equivalent signaling messages toward said destination, wherein the internet protocol multimedia subsystem further comprises: a presence server function; and a configuration for: intercepting predefined signaling messages directed to or coming from said at least one first home subscriber server; retrieving user information from the intercepted signaling messages; and sending said retrieved user information to said presence server function.