System and method for originating a call via a circuit-switched network from a user equipment device

摘要: Methods and apparatus for originating a Session Initiation Protocol (SIP) call from user equipment (UE) device in network environment including circuit-switched (CS) an IP multimedia subsystem (IMS) to called party are disclosed. In one illustrative example, when the SIP is originated by UE CS domain, Invite message which includes Uniform Resource Indicator (URI) or Tel URI of sent IMS (e.g. application server (AS) node). At AS node, pool E.164 numbers maintained as routing (IMRNs) utilized mapping otherwise associating with URIs. Thus, node dynamically allocates select number respect party's received device, returns it Response message, e.g., 380 (Alternative Service) message. Subsequently, dynamically-allocated setup identification at via mapping, so that may be properly routed towards party.