# LS on Initiation of New Work Item Q.IMS-INT-RS "IMS Interconnection Restoration Architecture and Procedures"

## Document Overview

This is a Liaison Statement (LS) from ITU-T Study Group 11 to 3GPP (for information) announcing the initiation of a new work item Q.IMS-INT-RS on "IMS interconnection restoration architecture and procedures" during the ITU-T SG11 meeting in Geneva, November 17-26, 2025.

## Main Technical Contribution

### New Work Item Initiation

ITU-T SG11 has initiated work on **Q.IMS-INT-RS**, which specifies restoration architecture and procedures based on a **shared backup interconnection point** to enhance service resilience in IMS interconnection scenarios.

### Scope of Q.IMS-INT-RS

The draft Recommendation covers the following technical areas:

#### 1. Restoration Architecture
- Defines the restoration architecture for IMS interconnection
- Focuses on shared backup interconnection point mechanisms

#### 2. Service Interruption Conditions
- Specifies conditions under which IMS interconnection service interruptions occur
- Identifies scenarios requiring restoration procedures

#### 3. Restoration Signaling Procedures
- Details the signaling procedures for IMS interconnection restoration
- Defines protocol interactions for failover and recovery

#### 4. Interface Descriptions
- Provides interface descriptions specific to IMS interconnection restoration
- Defines reference points and protocols for restoration mechanisms

## Collaboration Request

ITU-T SG11 is seeking collaboration with 3GPP on this subject matter, given the relevance to IMS interconnection which is a key area of 3GPP specifications.

## Reference Documents

The baseline text of Q.IMS-INT-RS is available in **SG11-TD657/GEN** (attached to the LS).