moq

Summary

The moq working group meeting covered several key topics including interop updates, live streaming via MOQ, a high-level status update, recent draft changes, catalog format discussions, secure objects, and implementation experiences with subscribe V2. The group discussed partial reliability model, the semantics of stream reset, fetch vs. subscribe, and publisher-related issues.

Key Discussion Points

Interop Update: Several implementations are working on draft 5. A call for a new MOQ interop czar was made to document behaviors of sample apps and define interop use cases.
Live Streaming via MOQ: A live stream of the IETF meeting was demonstrated using MOQ. The setup involved a webcam, laptop, IETF network connection, a relay in Los Angeles, and open-source software components.
High-Level Status Update: The group reviewed progress made over the past year, highlighting improvements to subscribe parameters, the object model, consensus on splitting up transport layers, and the adoption of the catalog draft. Focus areas for the remainder of the year include partial reliability, stream reset semantics, fetch vs. subscribe, security, and DDoS considerations.
Draft Changes: Discussion of updates in drafts 04 and 05, focusing on subscribe V2, priority in group send order, object status, and track status requests.
Catalog Format: A lengthy discussion on the catalog format, including the term "format" versus "packaging," extensibility, the use of IANA registries, the addition of a "type" attribute for tracks, and streaming format identifiers.
Secure Objects: Discussion on end-to-end encryption of data, drawing parallels with SRTP and SFrame. Keying mechanisms were noted as out of scope. The group discussed integrating SFrame with MOQ, including how to handle group IDs and object IDs.
Implementation Experience with Subscribe V2: Victor presented issues encountered implementing subscribe V2, particularly with range subscriptions, live edge behavior, and handling non-existent objects. The group discussed fetch vs. subscribe and potential solutions. The need to address how to handles objects from the past was discussed.

Decisions and Action Items

Interop Czar: The group will continue to seek a volunteer to serve as the MOQ interop czar. In the meantime, authors of interop applications should write drafts detailing how their implementations work.
PR Assignments: The editor will assign out PRs for various issues to interested contributors, who will then work on them and present them in weekly interim meetings for review.
Catalog Format Design Team: A design team will be formed to address concerns related to packaging, formats, and descriptions, involving relevant people from different streaming formats and the catalog draft.
Extensibility of Mott: Mo will file a MOQT issue to discuss whether trailers in the transport is needed.
Subscribe V2/Fetch PR: Victor was encouraged to submit a PR focusing on a revised subscribe/fetch mechanism, with an emphasis on eliminating backfill problems, and some discussion around excluding caches.

Next Steps

Address open issues and assigned PRs, and continue discussions in virtual interims.
Continue iterating on the secure objects draft, focusing on integration with SFrame.
Explore solutions for improving the subscribe V2 mechanism.
Further investigate extensibility of the object header and whether the transport needs trailers.
The catalog format design team should be formed.
Will to present his warp slides on Thursday.

Session Date/Time: 25 Jul 2024 20:00

moq

Summary

This session covered several key aspects of the Media over QUIC (moq) protocol, including Warp updates, diagnostic reporting, a proposed object model enhancement ("Peeps"), and track switching. Discussions focused on refining the protocol's object model, enhancing its efficiency, and addressing real-world implementation challenges. The session ended with administrative announcements about upcoming interims.

Key Discussion Points

Warp Update: Discussion on compartmentalization and how it splits things up, overview of the Lock packaging and Timeline Tracks PRs. Issues remaining with Warp.
Diagnostic Reporting: Discussion on sending diagnostic information like metrics and logging over moq tracks instead of HTTP. Concerns were raised about shared congestion context.
Peeps Proposal: Presentation of a new layer of hierarchy between groups and objects to improve stream mapping and temporal scalability. Strong interest expressed by attendees in seeing a PR for this work. Discussion on implications to stream and group handling.
Track Switching: Presentation of a solution for seamless track switching under congested scenarios, suggesting that the end subscriber hints to the relay. Alternative suggestions were given on how to make this work with existing APIs.
Missing Objects: Discussion on whether missing objects should be required, touching on implications for caching and fetch vs subscribe.
Subscribe Limits: Consideration of limiting the number of concurrent subscriptions. Trade-offs between quick-style max subscriptions and stream-per-subscription approaches were discussed.

Decisions and Action Items

Warp Adoption: Will to ask for adoption of Warp draft prior to the interim.
Mo Zanaty Action: Mo to send an email identifying communities to include in future moq discussions regarding media formats.
Peeps PR: Martin Duke to write a PR based on the "Peeps" proposal.
In-Person Interim: Attempt to find a venue in New York City. If not, the interim will be held in Cambridge, MA.

Next Steps

Continue discussions on diagnostic reporting, track switching, missing objects, and subscribe limits on the mailing list.
Prepare and review PRs for Warp updates and the "Peeps" proposal.
Determine the venue for the in-person interim in October.
Virtual interims will be bi-weekly for August, then return to weekly in September. Next virtual interim will be August 7th.