Session Date/Time: 09 Nov 2023 08:30

core

Summary

The IETF core working group meeting at IETF 118 covered several key documents and topics, including core YANG, group communication, pubsub architecture, DNS over CoAP, key updates for OSCORE, and performance measurement for CoAP. Discussions ranged from simplification and implementation feedback to addressing open issues and planning future steps.

Key Discussion Points

core YANG (Kirsten):
- Discussed the status of several YANG-related documents, including the informational RFC on YANG representation in CBOR, the SID allocation document (carsid) in ISG processing, Koma (Yang over CoAP), and the YANG Library.
- Implementer feedback suggests simplifying Koma.
- Concerns raised about all-or-nothing semantics for multiple RBCs/actions in one payload and potential use of YANG Library to address this.
- Reviewed and addressed working group last call comments.
Group Communication for CoAP (ESCO):
- Updates since IETF 112 including a new proxy subsection and transport section (multicast over 6LoWPAN).
- Clarified terminology related to group types and group URIs.
- Addressed comments from John Mattsson's review, including use cases for unsecured discovery (device onboarding).
Pubsub Architecture for CoAP:
- Implementation progress reported.
- Addressed Ayana related fields and security considerations.
- Discussed hosting of data resources elsewhere (broker) and compatibility with subscribers, potential for a separate document.
- David Nava raised concerns about scalability and topic discovery compared to MQTT, and implicit creation of topics.
DNS over CoAP:
- Mentioned amendment of introduction to contextualize constraint environment, and addition of research paper to appendix.
- Discussed service binding records (SVCB) and potentially starting a separate draft on the topic.
- Cachable OSCORE draft was referenced.
Key Updates for OSCORE:
- Mandated support for both 401 and reverse message flows.
- Clarified definition of kudos message.
- Updated existing methods for picking up internal score.
- Discussed more flexible message flow.
- Discussed the combination of kudos and application messages.
- Mentioned the use of non-random nouns and the use of counters as nonsense.
- Questioned whether to split out the section regarding OSCORE ID updates to a separate working group document.
CoAP Performance Measurement Option:
- Presented updates on the CoAP performance measurement option.
- Explained the use of spin bits and square bits for loss and delay measurements.
- Mentioned different application scenarios (non-proxy, collaborating proxies, non-collaborating proxies).
- Discussed implementation considerations for DTLS and OSCORE.
Topic from TTRG Meeting (Kirsten):
- Discussion on transport indication and the need for "coap+" syntax for literals with insufficient information to determine the protocol.

Decisions and Action Items

Group Comp Proxy Document: Adopt the group communication proxy document
core YANG: Address remaining working group last call comments and consider another short last call.
Group Communication for CoAP: Wait for confirmation from John Mattsson and the working group that review comments have been adequately addressed.
Pubsub Architecture for CoAP: Encourage more thorough reviews of the document.
DNS over CoAP: Summarize current status regarding SVCB records and include an informative reference to the problem statement.
Key Updates for OSCORE: Address open points and consider whether to split out the OSCORE ID update section into a separate document, will start with implementation.
CoAP Performance Measurement Option: The group will compare the results between different bit combinations.
Transport Indication: Update core interfaces and the core get documents, and ask customs to update our slip max.

Next Steps

Address all outstanding comments and issues in the various documents.
Continue implementation work for key projects (e.g., CoAP performance measurement).
Prepare documents for working group last call as appropriate.
Consider a tutorial session on core YANG at a future meeting.
Core interim meetings will continue on alternating weeks with the seabor working group, with the first one in 2 weeks from today.