Emergency signalling in an IP multimedia subsystem network

摘要

Embodiments of the present invention provide a method and apparatus for handling emergency signaling in an IP Multimedia Subsystem network. A Proxy-Call Session Control Function receives a message requesting set up of a session. The message is associated with an IP Multimedia Private Identity. The P-CSCF determines that the message relates to an emergency call. If an emergency override tag associated with the IMPI is provisioned or set at the P-CSCF, then the message is forwarding the SIP message to a Serving-Call Session Control Function (S-CSCF) for further handling. However, if an emergency override tag associated with the IMPI is not provisioned or set at the P-CSCF, the message is forwarded to an Emergency-Call Session Control Function (E-CSCF). The P-CSCF exercises control over the handling of emergency signaling, according to embodiments of the invention.