**Session Date/Time:** 22 Jan 2026 17:00

# [AVTCORE](../wg/avtcore.html)

## Summary

This AVTCORE interim virtual meeting focused on updates for three key drafts: `draft-ietf-avtcore-s-frame`, `draft-ietf-avtcore-rtcp-temporal-spatial-resolution` (Green Metadata), and `draft-ietf-avtcore-rtp-over-quic`. Key discussions included the integration of S-Frame with the Matter specification, the call for a second Working Group Last Call (WGLC) for the green metadata draft, and the ongoing development of RTP over QUIC, including a new sub-draft for ICE negotiation.

## Key Discussion Points

*   **S-Frame Status (`draft-ietf-avtcore-s-frame`)**
    *   Aaron Rosenberg provided an update on the draft, noting its importance for Matter camera standardization, which will adopt S-Frame for all cameras.
    *   The latest draft proposes:
        *   An updated packetization header supporting per-frame and per-packet S-Frame cryptography.
        *   A new SDP attribute for S-Frame negotiation, indicating offer and acceptance.
        *   A key derivation algorithm to generate individualized keys per SSRC (M-Line in WebRTC) from a single master key, ensuring cryptographic isolation and preventing CTR/key reuse across media streams.
    *   The key derivation and ratcheting mechanisms are based on existing RFC 9605 algorithms; no new cryptography is introduced.
    *   The goal is to enable direct S-Frame encryption from cameras into RTP without intermediate decryption, supporting various cipher suites and ratcheting schedules.
    *   The derivation of per-stream keys was highlighted as the most complex new part of the draft for implementation.
    *   An early review from the Security Directorate has already occurred.
    *   It was agreed that a dedicated presentation on this draft would be beneficial at the IETF 125 meeting in Shenzhen to facilitate wider security review.

*   **Green Metadata (RTCP for Temporal/Spatial Resolution `draft-ietf-avtcore-rtcp-temporal-spatial-resolution`)**
    *   The latest version (V7) addresses comments from Eric and Young Guang, focusing on background, development, and primary use cases (point-to-point video conferencing for battery saving, timely session completion, and software resource allocation).
    *   It corrects typos and mismatches in figures.
    *   The technology for spatial/temporal resolution changes is widely deployed and supported by various SDKs (NVIDIA, WebRTC API, Microsoft Draft) and codecs (AV1, H.267VC) without significant overhead.
    *   The draft aims to promote interoperability for exchanging resolution change capabilities across devices and platforms.
    *   The authors requested a second WGLC.

*   **RTP over QUIC (SDP Offer/Answer for RTP over QUIC `draft-ietf-avtcore-rtp-over-quic`)**
    *   Spencer Dawkins provided an update, noting progress on three open pull requests (PRs) since IETF 124.
    *   A PR clarifying the relationship between bundle and ROC flow was merged, defining the RTP session as equivalent to a ROC flow and bundled.
    *   Discussion on changing the draft title from "SDP for RTP offer/answer over QUIC" to a more generic "SDP for RTP over QUIC" was initiated via a PR, with a suggestion to consider adding text for declarative SDP usage.
    *   New work is underway to define a `ROC-ICE` transport protocol, potentially as a separate draft, to clarify ICE negotiation over QUIC. This aims to be similar to `UDP-ICE` and `TCP-ICE`, focusing on identifying "obvious differences" in areas like candidate selection, preferences, collection techniques, and connection initiation.
    *   Outstanding issues include:
        *   Specifying RTCP feedback replacement with QUIC equivalences (consensus is to gain more implementation experience first).
        *   Interaction with MassGDP Connect (deferred for now).
        *   Ensuring synchronization between the base ROC and SDP ROC drafts.
    *   The base ROC specification (`draft-ietf-avtcore-rtp-over-quic`) has expired, requiring attention before IETF 125.

*   **AVATAR Draft Adoption Call**
    *   A question was raised regarding the outcome of the AVATAR draft adoption call. The chairs acknowledged this needs review.

*   **HEVC WebRTC**
    *   Fippo was expected to provide an update but was unable to attend.

*   **Working Group Resources**
    *   Chairs reminded participants about the new repository for WG materials (e.g., agendas) and the GitHub organization for housing drafts.

## Decisions and Action Items

*   **Decision:** A security directorate review for `draft-ietf-avtcore-s-frame` will be initiated.
*   **Decision:** A second Working Group Last Call (WGLC) for `draft-ietf-avtcore-rtcp-temporal-spatial-resolution` will be initiated.
*   **Action Item:** Chairs (Jonathan Lennox, Marius Kleidel) to initiate a security directorate review for `draft-ietf-avtcore-s-frame`.
*   **Action Item:** Chairs (Jonathan Lennox, Marius Kleidel) to initiate a second WGLC for `draft-ietf-avtcore-rtcp-temporal-spatial-resolution` before IETF 125.
*   **Action Item:** Spencer Dawkins to consider adding text to `draft-ietf-avtcore-rtp-over-quic` regarding its usage in declarative SDP mode.
*   **Action Item:** Spencer Dawkins to notify the QUIC and AVT mailing lists when the `ROC-ICE` draft is ready for broader review.
*   **Action Item:** Chairs (Jonathan Lennox, Marius Kleidel) to review the outstanding adoption call for the AVATAR draft.
*   **Action Item:** Spencer Dawkins to address the expiration of the base ROC specification (`draft-ietf-avtcore-rtp-over-quic`) before IETF 125.

## Next Steps

*   A full presentation and discussion of `draft-ietf-avtcore-s-frame` at IETF 125, with an emphasis on security review.
*   Proceed with the second WGLC for `draft-ietf-avtcore-rtcp-temporal-spatial-resolution`.
*   Continue work on `draft-ietf-avtcore-rtp-over-quic` and the new `ROC-ICE` draft, soliciting feedback from relevant communities.
*   Chairs to resolve the AVATAR draft adoption call.
*   Participants are encouraged to utilize the new AVTCORE repository and GitHub organization for draft management.