**Session Date/Time:** 21 Jul 2025 15:00

# DMM Working Group Session

## Summary

The DMM working group met to discuss the status of four working group documents. The session covered updates on mobility transport network slicing for 5G (nearly complete), SRv6 and DMM architecture documents (in various phases), and mobile traffic steering. Key discussions focused on document status decisions, technical reviews, and adoption processes.

## Key Discussion Points

### Mobility Transport Network Slicing for 5G Document
- **Document Status**: Working group agreed the document should be informational, but one Ops AD suggested it should be standards track due to inclusion of a YANG module
- **Content Structure**: Draft follows slicing model defining AC as a service by IETF's work and 3GPP mapping model
- **Security Considerations**: Currently mentions security mainly on YANG and network configuration operation model, with some discussion on risks from reducing UDP source port number range
- **Working Group Last Call**: Question raised whether another WGLC is needed given the status change discussion

### SRv6 Mobile User Plane Architecture Update  
- **Technical Challenge**: Current M.GTP6.E behavior uses two SIDs in SRH which is difficult for high-speed hardware processing
- **Proposed Solution**: Make behavior hardware-friendly
- **Design Discussion**: Two options being considered for bit field ordering - following current specification vs. placing session field at end for easier hardware processing
- **Next Steps**: Need reviews before working group last call, targeting next IETF meeting for completion

### MAP Architecture Document
- **Post-Adoption Status**: Working group adoption completed, currently discussing API-related topics among authors
- **Key Discussion Points**: 
  - MapC API text syntax clarification needed
  - MapC API candidate options (N4 interface vs. other implementations)
  - Architecture independence from specific mobile service architectures
- **Real-world Deployment**: SoftBank has deployed SRv6 MAP in commercial network with successful trials for low-latency applications
- **Performance Concerns**: Questions raised about session scale, parameter processing efficiency, and co-hosting N3/N6 interfaces

### Mobile Traffic Steering Document
- **Scope**: Extends mobile communication system control for traffic steering across transport networks
- **Architecture Options**: Centralized controller vs. decentralized approaches
- **Operational Modes**: Three modes described - controller-centric, decentralized, and hybrid
- **Use Cases**: User plane anchor relocation, multiple anchors, node ephemerality, route optimization

## Decisions and Action Items

### For Mobility Transport Network Slicing Document:
- **Action**: Eric to chase down Ops ADs regarding YANG module standards track requirements
- **Action**: Request early security directorate review if helpful
- **Decision**: YANG modules do not have to be standards track (confirmed during meeting)

### For SRv6 Document:
- **Action**: Multiple volunteers signed up for document review
- **Action**: Authors to engage with Spring Working Group for feedback before last call
- **Action**: Formal request to Spring WG chairs for review during last call process

### For MAP Architecture Document:
- **Action**: Clarify MapC API text syntax in next revision
- **Action**: Don to review document and provide comments
- **Target**: Working group last call after review completion

### For Mobile Traffic Steering Document:
- **Action**: John and Carlos volunteered to review the document
- **Action**: Authors to uniform information model format and extend operations section

## Next Steps

- Security directorate review to be requested for mobility transport network slicing document
- Multiple document reviews to be completed by volunteers
- Continue technical discussions on mailing list for all active documents
- Prepare for working group last calls on documents ready for advancement
- Next meeting at IETF 124 in Montreal