Patent ID: 9674345
Date: 2017-06-06
CPC Classifications: H04L,H04M

Claim:
1. A call identifying method, comprising: receiving an Invite message sent by an IP multimedia subsystem (IMS) network element, wherein the Invite message carries called identifying information; when a called terminal identified by the called identifying information is a circuit switched (CS) network user, generating a CS call reference (CR) parameter or global call reference (GCR) parameter, so as to carry the CR parameter or the GCR parameter in an initial address message (IAM) to be sent to a CS network element; and generating a CS call reference header field according to the CR parameter or the GCR parameter, and sending a response message to the IMS network element, wherein the response message carries the CS call reference header field that is used to identify a call corresponding to the Invite message; wherein the CS call reference header field further comprises a protocol indication parameter which is used to indicate a protocol type used to define the CR parameter or the GCR parameter.