Session Date/Time: 13 May 2025 14:00

SCHC

Summary

This interim SCHC Working Group meeting focused on preparing for IETF 123 in Madrid and reviewing the status of active and expired working group documents. Key discussions included the duration and potential side meetings for the Madrid session, as well as detailed updates and next steps for individual drafts, particularly the SCHC Architecture document and its dependencies. The working group also celebrated the adoption of the Universal Option draft.

Key Discussion Points

IETF 123 Madrid Planning:
- Main Session Duration: A 1 hour 30 minute slot was deemed appropriate, similar to the previous IETF meeting, with a sense that a shorter duration would be insufficient.
- Side Meeting for Management: Initial discussion raised the need for a tutorial or extended discussion on management, particularly CoRECONF, due to its complexity and impact. It was suggested this could be an official meeting topic or an informal discussion.
- Side Meeting for SCHC Architecture: A strong interest was expressed in holding a dedicated 2-hour side meeting prior to the main WG session to intensely discuss and build consensus on the SCHC Architecture document, including terminology and the explanation of "stratum." This would also facilitate progress on dependent documents like the Generic SCHC Header and SCHC over IP.
- Potential Conflicts: 6Lo, T2RG, and CoRE were mentioned as groups to consider for scheduling.
Working Group Document Status Review:
- draft-ietf-schc-8824bis-coap: A new version is planned for Madrid. Updates will include aligning with OSCORE option changes in CoRE and integrating latest developments around the universal option (limiting changes to rule tables and examples, no wire format changes). A pending administrative point regarding a working group GitHub repository for the source was raised.
- draft-ietf-schc-disruptions: An update is expected for Madrid, specifically with changes related to the satellite part.
- draft-ietf-schc-architecture: Co-authors discussed the challenge of integrating concepts like "chiclet" and "stratum" into the informational architecture document. It was agreed that high-level descriptions could be included, but detailed specifications requiring "musts" and "shoulds" would need separate standard-track documents. The proposed side meeting aims to clarify this.
- draft-ietf-schc-icmpv6: This document is considered ready for WG Last Call, with no further work expected from authors. It was confirmed to be independent of the universal option.
- Expired Drafts Review:
  - draft-ietf-schc-protocol-numbers: This draft expired, having previously addressed UDP objections. Authors need to review it and potentially push for a new version for WG Last Call.
  - draft-ietf-schc-access-control: This draft is considered largely obsolete given recent progress in management mechanisms and is currently sleeping. It might be revisited if management work creates a clear need.
- Milestone-related Drafts (Standard Track):
  - Generic SCHC Header (standard track): It was noted that work on this document could be derived from the SCHC Architecture document once architectural discussions converge, making it a key goal for the Madrid side meeting.
  - SCHC over IP (standard track): This document is dependent on the architecture and protocol numbers drafts. It's also a target for discussion at the Madrid side meeting.
  - Rules discovery/negotiation and provisioning (standard track): Not specifically discussed in this meeting.
- draft-ietf-schc-ppp: This document is dependent on the SCHC Architecture progressing, particularly concerning the abstract definition of the SCHC header.
- draft-ietf-schc-universal-option: This document was formally adopted as a working group item.
- draft-ietf-schc-ipsec: Comments were recently submitted, and authors are expected to update the draft. Specific discussion points include vocabulary alignment and a proposed new machine operator for ranges.
- draft-ietf-schc-6lowpan: This document is nearing stability but is critically dependent on the SCHC Architecture's terminology and concepts remaining stable. Authors are waiting for the architecture draft to finalize.
New Drafts and Related Work:
- draft-luhong-schc-quick-compression: This new document was briefly mentioned and its presentation is expected at a future meeting.
- draft-lauron-schc-coreconf-management: A new document on CoRECONF management is expected to be issued soon, detailing how CoRECONF can manipulate SCHC rules and address atomicity.
- sidelocation: This draft was allowed to expire due to limited interest and potential overlap with the CoRE WG.
- SID Allocation: Recent developments in SID allocation, particularly PEN-based allocation allowing large numbers of SIDs without a registry, were highlighted as a relevant update for the WG.
- SCHC adaptation on ETSI stack for vehicular networks: An individual expressed interest in discussing preliminary work and potential collaborations in this area.

Decisions and Action Items

IETF 123 Madrid Main Meeting: Request 1 hour 30 minutes duration.
IETF 123 Madrid Side Meeting: Request a 2-hour side meeting to discuss draft-ietf-schc-architecture, to be scheduled preferably before the main SCHC WG meeting and potentially before the 6Lo WG meeting.
- Action Item (Chairs): Request the 2-hour side meeting for the SCHC Architecture document.
- Action Item (Chairs): Announce the side meeting details on the mailing list.
draft-ietf-schc-8824bis-coap:
- Action Item (Chairs / Pascal): Create a GitHub repository under the WG's control (e.g., LPWAN GitHub organization) for the document's sources.
draft-ietf-schc-icmpv6:
- Action Item (Chairs): Find a shepherd and prepare the document for Working Group Last Call.
draft-ietf-schc-universal-option:
- Action Item (Authors): Submit the document as a 00 version of the SCHC Working Group document.
draft-ietf-schc-protocol-numbers:
- Action Item (Pascal): Review the expired draft, make necessary updates, and prepare for submission to potentially proceed to WG Last Call.

Next Steps

Focus efforts on updating and discussing the SCHC Architecture document, with the dedicated side meeting in Madrid being a critical step.
Advance draft-ietf-schc-icmpv6 to WG Last Call.
Authors of draft-ietf-schc-8824bis-coap and draft-ietf-schc-disruptions to submit updated versions for Madrid.
Submit draft-ietf-schc-universal-option as a working group document.
Continue monitoring and contributing to dependent documents like draft-ietf-schc-6lowpan and draft-ietf-schc-ipsec.
Prepare for discussions on deriving standard-track documents (e.g., Generic SCHC Header, SCHC over IP) from the architecture work.
Look forward to the new CoRECONF management draft.
The next scheduled meeting is in two weeks.