**Session Date/Time:** 21 Jun 2023 14:00 # [CORE](../wg/core.html) ## Summary This interim meeting of the CORE Working Group focused on the progress and next steps for the `core-sid` and `core-comi` drafts, both of which require further working group last calls due to recent revisions and simplifications. Discussions also touched upon the `non-traditional-responses` draft, where an architectural split into informative and normative documents was proposed, along with a new option concept. ## Key Discussion Points ### CoAP YANG SIDs (`core-sid`) * **Status**: The draft was pushed back from ISG processing to the working group, necessitating a new Working Group Last Call (WGLC). * **Current Issues**: * Requirement for status information in the YANG SID allocation files. * The `pyang` tool used for generating examples was found not to output the complete strings (e.g., `/input` and `/output` for RPCs) and missed some tree points for SIDs. * **Proposed Fixes**: * Run a patched `pyang` using the existing SID file as input to avoid renumbering previously allocated SIDs. * Ensure all relevant SIDs are included, not just for data items, but also for specific points in the data tree (e.g., `/rpc/system/1717/*`). * Address editorial aspects to clarify that alternative SID allocation processes are acceptable, provided they meet the objectives outlined in Section 2 of the document. * **Timeline**: Process exception edits and `pyang` work to be done in parallel. Prepare draft -21 for discussion on the mailing list and potentially the next interim. Aim for a WGLC to be completed before IETF 117, allowing for further discussion at IETF 117 before resubmission to ISG. ### CoAP Management Interface (`core-comi`) * **Status**: Following feedback from the IETF London hackathon regarding complexity, a significant simplification has been implemented. * **Simplification Approach**: A non-radical solution was adopted, retaining GET, PUT, and DELETE operations for whole data access, but not introducing FETCH and PATCH for individual tree parts in this draft. * **Current Draft**: The branch incorporating these changes has been merged and submitted as draft -13, available for discussion on the mailing list. * **Wildcard Checks**: * Verify if the `pyang` changes required for `core-sid` also impact `core-comi`'s SID file examples. * Check if the replacement of `rc_yang_data` with `sx_structure` (as done in `core-sid`) is also needed in `core-comi`. * **Timeline**: Aim for a WGLC approximately concurrent with `core-sid`, or even earlier if outstanding questions are quickly resolved. Discuss outcomes at IETF 117 before submitting to ISG. ### Further Outlook (Yang Library and Binary Data Formats) * **YANG Library**: The document is nearing completion, but a check on its complexity level is warranted. * **Binary Data Formats for YANG**: There is growing interest in defining a way to switch existing YANG models from text-based data representations (e.g., text-based IP addresses, dates) to more efficient binary formats within CBOR. This is anticipated to be a significant design effort, requiring careful consideration of how new binary formats are introduced, and how evolution and differing levels of adoption are managed across deployments. ### Non-Traditional Responses * **Context**: The discussion was noted to be missing a key contributor, Christian, but some preliminary points were covered. * **Architectural Approach**: A sense of those present indicates support for a unifying architectural approach. It was suggested that the document could be split: * An informative document describing the broader architecture of CoAP beyond the HTTP blueprint, particularly concerning innovations like multicast responses and observe notifications. * One or more normative documents defining specific options (e.g., `num-additional-responses`, `multicast-timeout`), which currently serve more as illustrations in the draft. These normative options would require more thorough review, implementation experience, and potentially different timelines. * **Terminology**: Discussion around potentially confusing terms such as "multicast responses" (suggesting "multicast sent response" as clearer) and the broader category of "non-traditionally transmitted requests" (e.g., "configured requests" vs. "phantom requests"). * **New Option Idea (from Christian)**: A concept for a new option was brought up, similar to `multicast-timeout` but providing a continuous "send multiple responses until deactivated" mechanism. This would enable a privacy-preserving scenario involving chained proxies with OSCORE, where a generic instruction to forward multiple responses is preferred over explicit timeout values. This would need a corresponding deactivation mechanism, possibly drawing parallels with how the `observe` option deactivates requests. ## Decisions and Action Items * **Decision**: Proceed with a Working Group Last Call for the `core-sid` draft (expected to be a 2-week WGLC). * **Decision**: Proceed with a Working Group Last Call for the `core-comi` draft, aiming to run it in parallel with `core-sid`. * **Action Item**: Shepherd Michael Richardson (for `core-comi`) to be informed of today's discussion points. * **Action Item**: Initiate discussion on the `non-traditional-responses` draft on the mailing list, incorporating existing review comments (e.g., from Marco). * **Action Item**: Further explore the splitting of the `non-traditional-responses` draft into informative architectural guidance and separate normative option definitions. ## Next Steps * Continue discussions on `core-sid`, `core-comi`, and `non-traditional-responses` on the CORE WG mailing list. * Schedule the next interim meeting, tentatively aiming for two weeks. * Plan for `core-sid` and `core-comi` WGLCs to conclude before IETF 117. * Consider a potential side meeting at IETF 117 for further in-depth discussions on these topics, especially `non-traditional-responses` and new options, ensuring remote participation is supported. * Monitor progress on `attacks-on-coap` and `DNS` related topics for inclusion in future interim agendas.