| 摘要 |
A Serving Call Session Control Function (S-CSCF) receives a registration request message from a User Equipment (UE) and determines that this message carries not only a "reg-id" parameter, but also deregistration information, and also determines that the S-CSCF itself stores no registration information corresponding to the user identity. The S-CSCF then requests registration backup data associated with the user identity from a Home Subscriber Server (HSS) and compares it with the registration data comprised in the registration request message. If the registration backup data is different from the registration information in the registration request message the S-CSCF updates the registration backup data and returns updated registration backup data to the HSS for backup. If, however, the registration backup data is the same as the registration information in the registration request message, the S-CSCF instructs the HSS to deregister the user identity. |
