**Session Date/Time:** 25 Oct 2023 16:00

# [ASDF](../wg/asdf.html)

## Summary

This interim meeting focused primarily on preparations for rechartering the ASDF Working Group, including a review of the current SDF base document's status and a detailed discussion of potential new work items. A significant portion of the discussion revolved around the integration of non-IP protocol support via the `draft-brinkman-nipy` document and various extensions to the core SDF model, such as mapping files, instance/class support, and improved handling of links. The group also discussed the process for editing the existing charter text in preparation for the IETF 118 meeting in Prague.

## Key Discussion Points

*   **Note Well:** The IETF Note Well was read and its principles were reiterated to attendees.
*   **Non-IP Protocols (NIPY Draft):**
    *   Elliot provided an overview of `draft-brinkman-nipy-00`, which aims to provide Application Layer Gateway (ALG)-like functionality for non-IP protocols (e.g., Zigbee, BLE).
    *   The draft proposes a model using a restful interface for control and MQTT for events, serving as a content-neutral gateway infrastructure.
    *   It's seen as a way to instantiate the SDF model for non-IP devices, addressing the "dongle dash" problem in IoT deployments.
    *   The authors hope this work fits into a rechartered ASDF, covering part of the group's future scope.
    *   Further discussion on this topic is planned for the Thing-to-Thing Research Group (T2TRG) meeting on the Friday before IETF 118.
*   **SDF Base Document Update (draft-ietf-asdf-sdf-00):**
    *   The document (`-dash-16`) has passed Working Group Last Call, with additional reviews currently being processed.
    *   David Neo's review has been integrated, and another pull request is pending.
    *   The plan is to generate `dash-17` and submit it before Thanksgiving, potentially followed by another short Working Group Last Call.
*   **Rechartering Discussion (Carsten's Buckets):**
    *   **SDF Infrastructure:**
        *   **Mapping File Concept:** A mechanism to add ecosystem-specific information (e.g., OMA object IDs) to a base SDF specification without modifying the core. Current needs include a better name and tool awareness.
        *   **Class vs. Instance:** A recognized need to define how instance-specific information combines with SDF class information. No draft yet, but considered essential infrastructure.
    *   **Tool Support:**
        *   **SDF Compact Notation:** An informational document for easier human readability of SDF JSON files.
        *   **Ecosystem Mappings:** Documents explaining mappings to other ecosystems (e.g., Yang). This knowledge base exists but is not the primary rechartering motivation.
    *   **Extension Points:**
        *   **Links:** SDF currently lacks a robust way to describe links (e.g., restful links for CoAP/HTTP, or abstract links between instances/specifications). The `ASDF relations` draft addresses meta-level links. This work is reasonably advanced but needs further refinement and clarification on its relationship to instance/class support.
        *   **Extended Information for Digital Twin:** A new submission focusing on providing location and identity information for SDF instances, recognized as a specific case of the broader instance/class identity issue.
    *   **NIPY Work:** Consideration of how `draft-brinkman-nipy` fits into the ASDF charter, with further definition pending the Prague discussion.
*   **Custom Syntax / Renaming Affordances:**
    *   Michael Coster proposed allowing custom syntactical elements (e.g., renaming "SDF property," "SDF action," "SDF event") that map to existing SDF constructs. This could help internalize SDF within specific ecosystems.
    *   A sense of those present indicated that a clear proposal (draft or slides) would be beneficial for further discussion on whether this falls within charter scope.
*   **Review of Existing Charter:**
    *   Discussion on whether all existing charter milestones and objectives have been met. The IETF Journal article's mention of potential collaboration with an IRTF research group (UFMG) on formal description techniques was noted, though UFMG is currently focused on protocol verification.
    *   The charter's clause stating "we do not deal with serializations at all" was highlighted as a specific point for revision, as the NIPY work and general transport considerations challenge this existing boundary.
    *   The second paragraph of the current charter (listing entities for collaboration) was considered for revision or removal, as some relationships did not materialize as anticipated.

## Decisions and Action Items

*   **Decision:** The current ASDF Working Group charter text will be moved to a GitHub repository to facilitate collaborative editing through pull requests in preparation for rechartering discussions in Prague.
*   **Action Item:** Michael Coster to prepare a proposal (e.g., draft, two slides) outlining the concept of "custom syntax" or renaming SDF affordances for discussion.
*   **Action Item:** The ASDF chairs will post the current charter text to a GitHub repository and announce its location on the ASDF mailing list.
*   **Action Item:** Working group participants are encouraged to submit pull requests with proposed edits to the charter text on GitHub prior to the IETF 118 meeting.

## Next Steps

*   **IETF 118 in Prague:**
    *   A short slot is reserved for further discussion on the NIPY draft.
    *   The ASDF working group meeting will review and discuss proposed charter edits submitted via GitHub pull requests.
*   **T2TRG Meeting (Friday before IETF 118):** Discussion will include the non-IP segment and the NIPY work.
*   **IETF Hackathon:** Potential for some related work, though not explicitly detailed.