Session Date/Time: 03 Jan 2023 15:00

LPWAN

Summary

This interim meeting of the LPWAN Working Group provided updates on the status of current drafts nearing publication and focused primarily on discussing the proposed recharter text. Key drafts are progressing well through the RFC Editor queue and IESG review. The bulk of the meeting was dedicated to refining the scope and wording of the recharter proposal, particularly clarifying the existing scope, separating maintenance from new work, and defining specific "Foos" and "Bars" for future work.

Key Discussion Points

Draft Status Updates:
- [draft-ietf-lpwan-ipv6-chicover]: Remains in the RFC Editor queue and is currently in "EDIT" state, indicating active processing by the editor.
- [draft-ietf-lpwan-iot-chicover-fox]: Has seen significant recent activity and is anticipated to complete IESG review and be queued to the RFC Editor soon.
- [draft-ietf-lpwan-compound-ack]: Is currently under Shepherd review. Comments received during the chicover-v6 YANG model review are being addressed.
Recharter Discussion - General Context Text (Slide 9):
- The introductory text, intended as background, was discussed regarding its placement.
- A sense of those present indicated that adding a "Background" heading would make it clearer that this section is not part of the actionable charter items.
- A suggestion was made to rephrase the first sentence to better introduce the working group's current focus rather than its origin, though the Chair noted the importance of the original first sentence.
Recharter Discussion - Extended Scope (Slides 10-11):
- Clarity on Previous vs. New Scope: A key point of discussion was to clearly delineate between ongoing maintenance/continuation of previous work and entirely new work items.
  - It was suggested to group items 1 and 2 (OAM for SHC, and SHC over various "Foos") as continuation of the previous charter, and items 3-6 as new work.
  - This helps prevent scrutiny of previously agreed-upon scope.
- OAM for SHC (Item 1): No specific issues raised, considered existing work.
- SHC over Foos (Item 2):
  - Discussion on including Ethernet as a "Foo," potentially requiring definition of an EtherType for SHC, separate from IP/UDP.
  - The existing text saying "over IP" might be too restrictive if non-IP Foos like Ethernet are to be considered.
- SHC Header (Item 3): Discussion reiterated the need for a SHC header, particularly for non-IP/PPP/Ethernet Foos where an implicit SHC session indication might be missing. This would help identify which SHC session a packet belongs to between two peers.
- CoAP Optimization (Item 4): Acknowledged the need for optimizing SHC operations within CoAP, as current methods might not be efficient.
- Securing SHC Negotiation (Item 5): Reinforces the need to establish secure SHC session negotiation, potentially leveraging existing security mechanisms (e.g., from HIP).
- SHC Session Setup (Item 6): Focuses on defining mechanisms for establishing and agreeing upon rules for SHC sessions, similar to TCP's three-way handshake, to ensure peers operate under consistent rules.
- "Bar" Discussion (Higher-Layer Protocols for Compression):
  - Clarification was sought regarding what "Bar" protocols (protocols above SHC) beyond IP and CoAP would be targeted.
  - Examples suggested included ICMPv6 based protocols (for OAM), Lightweight M2M (LwM2M), IPv4, TCP, and DTLS.
  - The Chair expressed caution about listing specific protocols without a clear commitment from an author to produce a document, to avoid "scope creep" and unnecessary charter complexity.
  - It was noted that IPv4 compression had been a point of interest for 3GPP in the past, and TCP/DTLS were mentioned as potential areas of interest by Laurence (co-chair).
  - The general sense was to be specific with examples, but not over-commit without concrete proposals.
- Indicating SHC in Packets: Further discussion on how to indicate the presence of SHC within a packet, especially when not directly over IP. Options mentioned included a destination option in IPv6 or defining a new protocol encapsulation.

Decisions and Action Items

Decision: The proposed recharter text for the "Extended Scope" section will be modified to explicitly separate maintenance/continuation of previous charter activities (OAM for SHC, SHC over existing Foos) from new work items.
Decision: The "Bar" discussion will include examples such as "ICMPv6 based protocols," "Lightweight M2M," "IPv4," and "TCP/DTLS" as potential areas for SHC compression, acknowledging that work will only proceed if contributors emerge.
Action Item: The Chair will refine the recharter text based on the discussion, particularly regarding the background section's heading, the separation of previous/new scope, and the examples for "Bar" protocols.
Action Item: The Chair will discuss the refined recharter proposal, especially concerning the breadth of "Bar" protocols, with the Area Director (Eric).

Next Steps

The Chair will finalize the recharter proposal text, incorporating the feedback from this interim meeting.
The refined recharter proposal will be presented to the IESG for review and approval.
Progress on existing drafts (chicover-v6, iot-chicover-fox, compound-ack) will continue through their respective queues and reviews.