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: Integrated support for LTE and 5G networks, ensuring that high-speed packet-based services remain resilient. Summary Table: Typical Restoration Nodes Role in Restoration Primary Data Stored S-CSCF Serving node; handles session control SIP proxies, Contact info, Auth info HSS Central database; restores S-CSCF data Private User Identity, Registration Sets P-CSCF Entry point; detects UE status UE local IP, Security associations

: Mechanisms for the Proxy-CSCF to recover its relationship with the user equipment (UE) after a restart.

The primary goal of TS 23.380 is to ensure service continuity and high availability within the IMS core network. While network nodes (like the S-CSCF, HSS, and P-CSCF) are designed for reliability, maintenance or unforeseen failures can cause data loss or corruption. This document standardizes automatic restoration procedures to minimize user impact when these events occur. 2. Core Restoration Scenarios 123380

: Handling failures of application servers that provide specific services (e.g., VoLTE, messaging). 3. Key Technical Mechanisms

: 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. : Integrated support for LTE and 5G networks,

: 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.

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) While network nodes (like the S-CSCF, HSS, and

Restoration relies on specific signaling flows and data synchronization methods: