The specification has evolved through multiple "Releases" to keep pace with mobile technology:
: These are specific Diameter protocol messages (Server-Assignment-Request and Location-Information-Request) used by the HSS and S-CSCF to update and overwrite user data during restoration events. 123380
The specification covers several critical failure and recovery scenarios across the IMS domain: The specification has evolved through multiple "Releases" to
: Procedures for recovering the Home Subscriber Server, which acts as the central database for user identities and profiles. and authentication schemes—to the HSS.
: During initial registration, the S-CSCF backs up critical data—such as the list of SIP proxies, contact information, and authentication schemes—to the HSS.