Patent ID: 9560084
Date: 2017-01-31
CPC Classifications: H04L

Claim:
1. A method of changing allocation of serving Call Session Control Functions (S-CSCFs) to a user equipment (UE) of an IP Multimedia Subsystem (IMS) network, wherein the UE is being provided with services via a first S-CSCF allocated to the UE, the method comprising: receiving at the first S-CSCF criteria for de-allocating the first S-CSCF from the UE, the received criteria specifying one or more conditions that are required to be met prior to de-allocating the first S-CSCF from the UE; receiving at the first S-CSCF a de-allocation instruction; in response to receipt of the deallocation instruction, the first S-CSCF determining if the one or more conditions specified in the criteria are met; and if the one or more conditions specified in the criteria are met, the first S-CSCF de-allocating itself from the UE, the one or more conditions including: wherein the received criteria for de-allocating the first S-CSCF is included in an instruction received from a home subscriber server (HSS) for re-allocating the UE for the first S-CSCF.