Digital cellular telecommunications system (Phase 2+); Universal Mobile Telecommunications System (UMTS); LTE; IMS Restoration Procedures (V9.6.0; 3GPP TS 23.380 version 9.6.0 Release 9)
The present document specifies the procedures required in 3GPP IMS to handle a S-CSCF service interruption scenario with minimum impact to the service to the end user. NOTE: IMS Restoration Procedures covering service interruption of other network elements are not defined in this version of the specification.