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MoQT draft-22 Control Message Types

MoQT draft-22 defines 19 control message types and marks 6 code points reserved — 25 rows in all. The type code is the first field of every control message, so this is the table a decoder dispatches on.

The rows come from the draft's own Control Messages table, not from a hand-kept list. For the field layout of a message, follow its section link into the draft-22 text.

What changed since draft-21

Section titled “What changed since draft-21”

No control message type was added, removed, renumbered or renamed between draft-21 and draft-22.

Control message types

Section titled “Control message types”
Type Message Stream Defined in Test vectors
0x01 RESERVED — SETUP for version 00 — — —
0x40 RESERVED — CLIENT_SETUP for <= 10 — — —
0x41 RESERVED — SERVER_SETUP for <= 10 — — —
0x20 RESERVED — CLIENT_SETUP in <= 16 — — —
0x21 RESERVED — SERVER_SETUP in <= 16 — — —
0x2F00 SETUP Control §9.1 13
0x10 GOAWAY Control, Request §9.2 6
0x3 SUBSCRIBE Request, First §9.6 50
0x4 SUBSCRIBE_OK Request §9.7 11
0x22 PUBLISH_STATE_NOTIFY Request §9.10 9
0x1D PUBLISH Request, First §9.8 16
0x1E RESERVED — PUBLISH_OK in <= 17 Request — —
0xB PUBLISH_DONE Request §9.9 13
0x16 FETCH Request, First §9.11 25
0x18 FETCH_OK Request §9.12 7
0xD TRACK_STATUS Request, First §9.13 4
0x6 PUBLISH_NAMESPACE Request, First §9.14 4
0x50 SUBSCRIBE_NAMESPACE Request, First §9.15 5
0x51 SUBSCRIBE_TRACKS Request, First §9.18 19
0x8 NAMESPACE Request §9.16 4
0xE NAMESPACE_DONE Request §9.17 3
0xF PUBLISH_SKIPPED Request §9.19 4
0x2 REQUEST_UPDATE Request §9.5 15
0x7 REQUEST_OK Request §9.3 20
0x5 REQUEST_ERROR Request §9.4 24

25 rows from the Control Messages table of draft-22. The test-vector column counts the encode/decode vectors moqtap publishes for that type; it is a cross-check, not part of the registry.

The Stream column is the draft's own: Control for messages on the session control stream, Request for messages on a per-request bidirectional stream, and First for a message that must open one.

Cross-check against the test-vector corpus

Section titled “Cross-check against the test-vector corpus”

moqtap publishes 252 encode/decode vectors for draft-22 across 20 message types, and all three moqtap implementations validate against them. Comparing that corpus with the draft's table is an independent check on this page: all 19 assigned types have vectors.

Neither source has a message type the other lacks.

Where these numbers come from

Section titled “Where these numbers come from”

The table is parsed from table-5 of draft-ietf-moq-transport-22, in the frozen rendering this site keeps at spec-sources/draft-22.html. That file hashes to e3c5f571d3eca49041acb03750dbdbcc2882669aeb5e22c5d98cfaa54d6696b5, which is the same source_sha256 the moqtap codec's committed registry extraction records for draft-22 — the two inputs are provably the same document.

Control message types are not an IANA registry in the drafts, so they are not part of the codec's registry extraction; the table id above is taken from that extraction's record of the tables it deliberately excluded, which is how this page finds the right table without guessing.

draft-22 error codes · Read draft-22 section by section

Control message types in other drafts

Section titled “Control message types in other drafts”

moqtap covers drafts 07 through 22.

All MoQT control message types, draft by draft · How control messages work