IETF 121 MOQ Working Group Update: Key Decisions and Next Steps

IETF 121 Summary

The MOQ Working Group met at IETF 121 for two sessions covering the latest developments in Media over QUIC standardization. Here are the key takeaways.

Catalog Format Consensus

The working group reached rough consensus on the catalog format (draft-ietf-moq-catalogformat). The catalog is a JSON-based document that describes:

• Available tracks and their properties
• Codec information (audio/video codecs, parameters)
• Track relationships (e.g., audio/video synchronization)
• Quality variants for adaptive streaming

The agreed format is designed to be extensible while keeping the common case simple:

{
  "version": 1,
  "streamingFormat": 1,
  "tracks": [
    {
      "namespace": "conference/room1",
      "name": "video",
      "packaging": "loc",
      "renderGroup": 1,
      "selectionParams": {
        "codec": "av01.0.08M.10",
        "width": 1920,
        "height": 1080,
        "framerate": 30,
        "bitrate": 3000000
      }
    }
  ]
}

Relay Protocol Discussion

A significant portion of the session focused on relay-to-relay communication. Key discussion points included:

• How relays discover and connect to upstream relays
• Authentication and authorization between relays
• Cache management and eviction policies
• Load balancing across relay clusters

No consensus was reached on this topic, and it will be a focus area for upcoming interim meetings.

Priority and Delivery Order

The group discussed how publishers signal priority and delivery preferences:

• Group order: Should objects within a group be delivered in order?
• Track priority: When bandwidth is limited, which tracks get priority?
• Drop policy: How should relays handle congestion — drop old objects or new ones?

Timeline

The chairs indicated that moq-transport is targeting Working Group Last Call (WGLC) in 2025, though this depends on resolving the remaining open issues. The catalog format may advance to WGLC sooner, as it has fewer open issues.