123380

For further technical reading, the latest versions (such as ) are available via the ETSI Deliverable Repository . ETSI TS 123 380 V9.6.0 (2014-03)

: Procedures for recovering the Home Subscriber Server, which acts as the central database for user identities and profiles.

: Focused on basic IMS recovery for GSM and UMTS. 123380

The specification covers several critical failure and recovery scenarios across the IMS domain:

: Handling failures of application servers that provide specific services (e.g., VoLTE, messaging). 3. Key Technical Mechanisms For further technical reading, the latest versions (such

: Procedures for when a Serving-Call Session Control Function (S-CSCF) fails or loses registration data. It defines how the Home Subscriber Server (HSS) and other nodes collaborate to re-register users or restore sessions.

Restoration relies on specific signaling flows and data synchronization methods: It defines how the Home Subscriber Server (HSS)

: 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.