Patent ID: 9467485
Filing Date: 2016-10-11
CPC Classification: H04L,H04W

Claim Text:
1. A method for switching a session of an IP Multimedia Subsystem (IMS) network, comprising: receiving, by an Emergency Access Transfer Function (EATF) entity, an emergency call which is routed by a Proxy-Call Session Control Function (P-CSCF) in a call initiation domain; anchoring, by the EATF entity, the emergency call, and routing the emergency call to an Emergency-Call Session Control Function (E-CSCF); receiving, by the EATF entity, a call transfer invite message sent by a Mobile Switching Center (MSC) server in a call termination domain; and when identifying that the call transfer invite message is an invite message inviting to perform transfer of the emergency call, performing, by the EATF entity, media negotiation, and sending a response message carrying media information to the MSC server in the call termination domain.