Patent ID: 8228787

Claim:
A method for disaster recovery, comprising: obtaining, when a redundant Call Session Control Function (CSCF) is triggered, by the redundant CSCF, user backup data of registered IP Multimedia Subsystem (IMS) Private User Identities (IMPIs) that are associated with IMS Public User Identities (IMPUs) and user service configuration data of the IMPUs in an IMS subscription from a network storage device of a user, wherein the step of obtaining comprises: obtaining, by the redundant CSCF, information of the registered IMPIs that are associated with the IMPUs in the IMS subscription transmitted by the network storage device of the user; determining, by the redundant CSCF, an IMPU to be recovered according to the obtained information of the registered IMPIs, and requesting the network storage device of the user to recover user service configuration data of the IMPU and user backup data of a registered IMPI directly associated with the IMPU; and receiving, by the redundant CSCF, the user service configuration data of the IMPU and the user backup data of the registered IMPI directly associated with the IMPU carried in a response returned by the network storage device of the user; and performing, by the redundant CSCF, a corresponding service according to the obtained user backup data of the registered IMPIs and user service configuration data of the IMPUs in the IMS subscription.