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

Abstract:

In one aspect, an application server (AS) node comprises a processor configured to receive a first SIP Invite request from the UE device, the first SIP Invite request having call information which includes a URI of a called party and data indicating that the first SIP Invite request is for a bearer over a circuit-switched (CS) network. An E.164 number is associated with the call information in the first SIP Invite request and a SIP response including the E.164 number is sent to the UE device in response to receiving the first SIP Invite request. When a call setup message including the E.164 number received from the CS network, the received E.164 number is verified if it is valid and if so, the call information is identified based on the E.164 number and is sent to the called party via a second SIP Invite request.