Session Date/Time: 27 Jul 2022 14:00

moq

Summary

The moq session focused on reviewing the draft charter, discussing proposed wording, and gauging community interest in forming a working group. Key discussions revolved around the scope of use cases, the terminology for media delivery (e.g., "push" vs. "pull"), the specification of a mandatory-to-implement media format, and the clarity of encryption requirements. Several charter text changes were proposed and accepted to address immediate concerns. Community polls indicated strong interest in the problem statement and a willingness to contribute, with a majority supporting the formation of a working group. However, there was no consensus on mandating a specific media format. A scheduled technical presentation was postponed due to audio issues.

Key Discussion Points

Use Case Wording: Discussion arose regarding the phrasing "may address use cases including" with a suggestion to strengthen it to "shall include at least" to clarify the intent. Sanjay Mishra volunteered to propose a PR for this change.
"Push Protocol" Terminology: Concerns were raised by Victor Vasilev, Luke Curley, and Noam Mazanati that "push protocol" might be too restrictive or imply a purely unidirectional flow, conflicting with aspects like media requests or negotiation. The chairs decided to accept a PR to remove "push" from the charter, deeming it a design decision for the working group and a discussion that was "rat holing."
Scope of Use Cases: Kyle Rose and Bernard Aboba expressed concerns about the broadness of use cases (live streaming, gaming, media conferencing), suggesting it might be "boiling the ocean" and that a more focused approach (like HTTP for Quick) would be better. Colin Jennings and Carol disagreed, arguing for a generic, low-latency, highly scalable video tool that serves multiple use cases, emphasizing the synergy gained by tackling them together and avoiding mapping problems between ingest and distribution. Sanjay Mishra suggested prioritizing use cases within the working group if formed.
Mandatory to Implement Media Format: Stefan Wenger, York Zschaler, and Noam Mazanati raised strong objections to specifying a mandatory-to-implement media format, citing political/licensing complexities (AV1 vs. H.26x), the difficulty of agreeing on a single format across diverse use cases, and the risk of mandating an outdated codec. Luke Curley highlighted the practical distribution challenges and caching costs associated with supporting multiple mandatory codecs. Ted proposed modifying the text to "may specify a mandatory to implement media format for specific use cases," but a subsequent poll showed a significant trend against mandating a format, with no clear consensus.
Encryption and Metadata Clarity: Ecker, Philip Hanbaker, and Bernard Aboba sought clarification on the encryption text, particularly regarding "end-to-end encryption" (proposing "ends plural" to acknowledge multiple hops/transcoding), the role of unencrypted metadata, and authentication. Colin Jennings clarified that Quick provides hop-by-hop encryption, while the charter refers to optional content E2E encryption (e.g., using MLS) and authenticated but unencrypted envelope data (transport metadata) for relay/caching functionality, similar to how IP addresses are unencrypted for network routing. Noam Mazanati emphasized that the protocol should identify E2E encrypted content and its context, not define the encryption itself. PRs (specifically #60 and a later one from Ecker) were accepted to update this text for clarity.
Coordination with Mops: Leslie Daigle, co-chair of the Mops WG, requested that moq coordinate with Mops to avoid isolated work and ensure broader industry representation for video delivery over IP. A PR to add Mops to the coordination list was accepted.
Authentication Mechanism: Victor Vasilev expressed skepticism about the "simple method of authentication to access media," suggesting such wording often leads to insecure or insufficient solutions (e.g., "stun encrypted with MD5") and should potentially be left out of the charter or as an extension.
Discovery Mechanisms: Spencer Dawkins questioned the lack of guidance on discovery mechanisms for sources, sinks, and relays, highlighting potential interoperability and privacy concerns if not addressed.
Caching and Intermediates: Omar Shapiro sought clarification on the relationship between "raw Quick" and "cache-friendly" mechanisms, noting that large-scale caching often implies HTTP. Eric Rescorla added that semi-live/DVR use cases blur the lines between live and on-demand, requiring early consideration for how caching and middle boxes fit in. Colin Jennings explained that "cache-friendly" refers to designing the protocol to enable the building of media-specific caches, not necessarily relying on existing HTTP CDNs. Victor Vasilev suggested that intelligent dropping/selection of media chunks might imply more advanced knowledge of media content for transport, blurring the line between transport and content awareness.

Decisions and Action Items

PRs Accepted:
- PR to remove "push" from "media publication protocol" (addressing Victor Vasilev's feedback).
- PR to add the "Mops" Working Group to the list of groups for coordination (per Leslie Daigle's request).
- PRs #60 (from Richard Barnes) and a subsequent PR from Ecker to clarify the encryption text were accepted to better reflect the intent for optional end-to-end encryption of media content while allowing relays to access authenticated transport metadata.
"Mandatory to Implement Media Format" Poll Result: The community poll showed no consensus (20 for, 63 against, with 152 total participants) on whether the charter should specify a mandatory-to-implement media format (either generally or on a use-case-specific basis). This indicates a strong leaning against such a mandate and suggests further work is needed on this aspect of the charter.
Technical Presentation Postponed: Suhas's presentation on "quicr" was postponed to a future interim meeting due to audio quality issues preventing clear communication.
Action Item: Sanjay Mishra to open a PR to update the use case wording from "may address use cases including" to "shall include at least" or similar.
Action Item: General: Participants are encouraged to open PRs or GitHub issues on the charter repository with specific proposed text changes and discuss them on the mailing list.

Next Steps

The chairs will consult with the Area Directors regarding the formation of the working group based on the buffer results and community feedback.
Further refinement of the charter text will be required, particularly concerning the "mandatory to implement media format" and the remaining aspects of authentication and discovery mechanisms, considering the community's input.
If a working group is formed, the chairs will discuss scheduling an early interim meeting (online or in-person before IETF 115) to kick off technical discussions, including the postponed "quicr" presentation, given that the buff was primarily charter-focused.
The community is encouraged to continue discussions on the mailing list and contribute to the charter draft via GitHub PRs and issues.