Patent ID: 11445560

Abstract:
A method of establishing a Voice over Internet Protocol, VoI P, call between a calling User Equipment, UE, and a called UE, wherein said calling UE is served by a core network via a packet-switched radio access network, PS-RAN, and wherein a bearer is to be established between said calling U E and a gateway node in said core network, over said PS-RAN, for obtaining access to an Internet Protocol, IP, multimedia subsystem, I MS, network, wherein said method comprises the steps receiving, by a an IMS Call Session Control Function, CSCF, node a notification message thereby notifying said I MS node that said VoIP call establishment is in progress and initiating, by said I MS CSCF, re-establishment of said bearer between said calling UE and said gateway node, over said PS-RAN, in case said establishment of said bearer has failed due to a temporary failure.