Session Date/Time: 18 Mar 2024 05:30

webtrans

Summary

This session covered the latest updates on WebTransport, focusing on interop runner updates, a W3C update on browser-side progress, and discussions on WebTransport over HTTP/2 and HTTP/3. Key topics included session management, stream handling, flow control, and TLS keying material exporters.

Key Discussion Points

Interop Runner: Martin Seemann has added WebTransport support to his QUIC interop runner, enabling tests between Chrome and WebTransport Go.
W3C Update: The W3C WebTransport group provided an update on their progress towards Candidate Recommendation and Proposed Recommendation. Highlights included the lost AUTF back option for stream creation, support for reliable HTTP collections, and the addition of new stats.
Anticipated Concurrent Incoming Unidirectional Streams: Discussion about the newly added attribute, including its purpose and the minimum requirement set by the browser.
WebTransport over HTTP/2: Notable updates included pulling in new capsules for session management and clarifying the settings requirements for clients and servers. The group agreed to not rename the capsules for session management ("closed web transport session" and "drain web transport session").
WebTransport over HTTP/3: Discussions focused on issues related to stream reset reliability, flow control, and TLS key exporters. Martin Seemann raised a concern about head-of-line blocking with the proposed flow control mechanism.
Flow Control Head-of-Line Blocking: Martin Seemann raised a point about potential head-of-line blocking issues related to capsules being sent on a single stream. Several alternative solutions were mentioned, but they were deemed too complex to implement for the current version of the specification.
TLS Key Exporters: Reopened discussion on key exporters and a proposal to point to TLS spec.

Decisions and Action Items

Action Item: Editors to prioritize generating PRs for open issues.
Decision: The proposed flow control mechanism for WebTransport over HTTP/3 will be used, despite the potential for head-of-line blocking.
Action Item: Ensure documentation specifies high priority for the control stream, as noted by Victor.
Decision: TLS Key Exporters proposal is considered good enough and will be merged if no significant objections are raised.
Action Item: Martin Seemann to file an issue about his concerns regarding head-of-line blocking.

Next Steps

Editors to finalize and submit PRs for the remaining open issues.
Review and implementation of the current WebTransport over HTTP/3 draft, paying close attention to stream reset reliability.
Monitor the mailing list for discussion regarding the new PRs and potential issues.
Assess the need for a virtual interim meeting based on the progress of the PRs and any arising points of contention.