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