Roaming Scenarios Based on SIP

This work deals with the problem of IP mobility amongst different access domains. In particular the problem of the integration of the SIP (Session Initiation Protocol) signaling within a roaming environment is considered. Although SIP natively supports only user mobility, it can be also used to manage full terminal mobility. In this work different SIP registration scenarios for the so-called Pre-call terminal mobility are identified and described in detail. The general aim is allowing mobile users to remain reachable under the same application-layer identifier as terminals change IP address and thus while roaming. In the proposed scenarios the problem of service control from both home and foreign domains has been also considered.