draft-ramadan-moq-multicast-00 | Individual submission | -00 posted 2026-10-14 | 27 pages | Standards Track | Datatracker
Authors
- Omar Ramadan (Blockcast)
Abstract
Describes how MoQ integrates multicast delivery with unicast QUIC sessions to achieve scalable live streaming. MMTP (MPEG Media Transport) packets are used uniformly across every delivery path — native SSM (Source-Specific Multicast), AMT tunneling, and broadcast television — while catalog-based endpoint discovery lets a receiver find the right source regardless of path. A manifest-based authentication profile, “bc-provenance,” protects multicast content through per-group signed digests, so a receiver can verify symbols independently of the delivery path or FEC recovery — securing an otherwise integrity-unprotected UDP multicast channel.
Why It Matters
Unicast QUIC does not scale to broadcast-sized audiences; native IP multicast does, but is integrity-unprotected and awkward to discover and authenticate. This draft is the delivery-path half of the Blockcast broadcast-interop cluster: it lets MoQ ride SSM / AMT / broadcast for the many-receiver leg while keeping the unicast QUIC control relationship, and it adds the signing layer multicast has always lacked.
Key Design
- MMTP as the uniform packet. The same MMTP packet format (from the companion moq-mmt draft) is carried over native SSM, AMT tunnels, and broadcast TV — one wire shape across heterogeneous paths.
- Catalog-based endpoint discovery. Receivers discover multicast sources and their parameters through the MoQ catalog, maintaining the unicast-style discovery model on a multicast channel.
bc-provenanceauthentication. A manifest-based profile protects content with per-group signed digests, letting a receiver verify each symbol regardless of which path delivered it or whether it was reconstructed by FEC (moq-fec).- Multicast ⟷ unicast bridging. Multicast delivery is paired with the unicast QUIC session rather than replacing it, so control, authorization, and fallback stay on the unicast leg.
Relationship to other work
- Part of a three-draft Blockcast cluster (Omar Ramadan, 2026-10-14). It consumes [[moq-mmt|
draft-ramadan-moq-mmt-00]]‘s MMTP packets and leans on [[moq-fec|draft-ramadan-moq-fec-00]] for recovery on the lossy multicast leg;bc-provenancesecures what FEC reconstructs. - A distinct take on discovery. Where [[moq-discovery|
draft-jennings-moq-uri-00]] defines amoqtURI scheme and DNS-based discovery for unicast, this draft defines catalog-based endpoint discovery for multicast/broadcast sources — a different problem on the same ecosystem axis. - Broadcast-over-MoQ direction. With moq-msfts / moq-mpegts (MPEG-TS packaging) and the MMT/FEC companions, this completes a Blockcast-driven push to make MoQ a first-class bridge to ATSC 3.0 / ARIB-style broadcast.
Status
Individual submission — not adopted by the MOQ working group. Posted 2026-10-14; no mailing-list announcement at submission time. See moq-mmt, moq-fec, moq-discovery, moq-transport, catalog-format, discussions-2026-10.