Patent ID: 8069365

Claim:
A method for realizing an Internet protocol multimedia subsystem (IMS) disaster tolerance, comprising: receiving, by a serving call session control function (S-CSCF), a user registration, and backing up necessary data which is required when a user service processing is restored on a storage entity in a network; receiving, by an interrogating CSCF (I-CSCF) of the user's home domain, a service request of the user, and if it is found that the S-CSCF currently providing a service for the user fails, assigning a new S-CSCF to the user, and forwarding the service request to the newly assigned S-CSCF; and interrogating and acquiring, by the newly assigned S-CSCF, subscription data of the user and the necessary data backed up by the original S-CSCF from the storage entity, and then restoring the user service processing according to the subscription data and the necessary data.