Session Date/Time: 31 Jan 2023 15:00

LPWAN

Summary

This interim meeting of the LPWAN Working Group covered updates on several drafts, notably the SHIC YANG Data Model (now in auth48 as RFC 9363) and the SHIC Compound Arc (shepherd review complete, ready for IESG submission). A significant portion of the meeting was dedicated to the ongoing re-chartering discussion, refining the working group's scope to include multi-hop networks, zero-energy scavenging devices, and broader SHIC applicability. Finally, the group began a detailed discussion on a proposed reorganization of the Architecture document, aiming for a more generic, multi-hop-first approach rather than starting with star topologies.

Key Discussion Points

Meeting Logistics:
- Interim meetings are held bi-weekly at a consistent time.
- New participants interested in presenting should email the LPWAN mailing list to request a slot for future interims.
Draft Status Updates:
- SHIC YANG Data Model:
  - The draft is currently in AUTH48, with RFC number 9363 assigned.
  - Minor editorial changes are pending from the RFC Editor.
  - A participant proposed two changes: re-arranging a union in the model for better validation tool compatibility and adding a distinction for CoAP options from CoAP headers. These changes do not alter semantics and will be applied with a new revision number on GitHub.
  - Discussion on requesting SIDs for the YANG data model highlighted that the SID registry at IANA is not yet established, pending a dedicated RFC. Provisional SIDs may be considered in the interim.
- SHIC over NB-IoT: The document is in the RFC Editor queue.
- SHIC Compound Arc: The shepherd review is complete. The working group last call was confirmed to have been completed in October-November 2021. The document is ready for submission to the IESG for publication.
WG Re-chartering:
- This was the third discussion of the re-chartering text, following previous discussions at IETF-115 and earlier interims.
- The background text for the charter is considered stable.
- Scope: The updated scope aims to enable SHIC for multi-hop, non-LPWAN, and Zero Energy Scavenging devices. It also explicitly lists various protocols and tools for which SHIC could be used (e.g., DTLS, CoAP, TCP, IP tunnels).
- SHIC EtherType: Discussion arose regarding the mention of a "SHIC EtherType" in the charter text. While important for SHIC transport over Ethernet, it was suggested to generalize this point as an example, as the specific work for an EtherType would likely be an IANA/IETF-internal process rather than a direct LPWAN WG output. The text will be adjusted to present it as an example of transport enablement.
- "Remote Endpoint" and "Multi-hop": Clarification was sought on the term "remote endpoint" in the context of SHIC sessions. It was explained that this refers to the application and device endpoints across an L2/L3 network, where SHIC previously focused on one-hop but is now expanding to multi-hop scenarios. There was agreement to use "multi-hop" more explicitly in the charter to describe this expansion.
- Maintenance and New Work: The charter clearly states maintenance of existing mechanisms as a work item. New items include SHIC over multi-hop networks and support for IP tunnels.
Architecture Document Reorganization (draft-ietf-lpwan-architecture):
- A participant presented a proposal to reorganize the document, which currently starts with a focus on one-hop/star topologies.
- The proposal suggests moving towards a more generic, multi-hop architecture as the primary model, with star topologies described as a specialized or collapsed version of the generic model.
- Key proposed changes include merging introductory sections (LPWAN technologies, SHIC profiles, applicability) and integrating aspects of existing section 5.1 (LPWAN architecture) earlier in the document.
- The discussion also touched on the need to explicitly include "rules management" as a core architectural element, possibly within the existing section 7 on deployment and lifecycle.
- No firm decisions were made on the exact structural changes due to time constraints, but the direction towards a generic, multi-hop-first architecture was favored.

Decisions and Action Items

Decisions:

The SHIC Compound Arc document (draft-ietf-lpwan-shic-compound-arc) will be submitted to the IESG for publication.
Minor editorial changes proposed for the SHIC YANG Data Model (RFC 9363) by a participant (rearranging a union, distinguishing CoAP options) are approved and will be implemented with a new revision number.

Action Items:

Pascal: Submit the SHIC Compound Arc document to the IESG for publication.
Pascal: Send the latest version of the re-chartering draft to the LPWAN mailing list for further review and feedback.
Lohann (with Anna's return): Implement the approved minor editorial changes to the SHIC YANG Data Model, including a new revision number on GitHub, and coordinate with the RFC Editor.
Lohann: Continue to track the development of the IANA SID registry RFC and prepare for SID allocation for the SHIC YANG data model once the registry is established.
Ivan and team: Continue developing the proposed reorganization and content for the Architecture document (draft-ietf-lpwan-architecture), focusing on a generic, multi-hop-first approach. This work will be discussed further on the mailing list and in the next interim.
New Participant (Yu): Send an email to the LPWAN mailing list to request a slot to present their IPv6 work at the next interim meeting.

Next Steps

Continued discussion on the LPWAN Working Group re-chartering text via the mailing list, aiming for working group consensus.
Further development and discussion on the reorganization and content updates for the Architecture document (draft-ietf-lpwan-architecture) on the mailing list and at the next interim.
The next interim meeting is scheduled for two weeks from now, around February 14th.