MoQT draft-21 Control Message Types

MoQT draft-21 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-21 text.

What changed since draft-20

No control message type was added, removed, renumbered or renamed between draft-20 and draft-21.

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	41
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	24
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	11
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-21. 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

moqtap publishes 234 encode/decode vectors for draft-21 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.

Note

The corpus names one code point differently from the draft: 0x07 is REQUEST_OK in the draft and PUBLISH_OK in publish-ok.json. The draft's name is the one shown above; the corpus keeps the older filename as an alias so vectors written against an earlier draft still resolve.

Where these numbers come from

The table is parsed from table-5 of draft-ietf-moq-transport-21, in the frozen rendering this site keeps at spec-sources/draft-21.html. That file hashes to 79aa14517f85a3ff22de1d7ad7d24af7eacb7a7a3e16ed2039a7e2ce763b02fb, which is the same source_sha256 the moqtap codec's committed registry extraction records for draft-21 — 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-21 error codes · Read draft-21 section by section

Control message types in other drafts

moqtap covers drafts 07 through 21.

• draft-21 — 25 types
• draft-20 — 25 types
• draft-19 — 24 types
• draft-18 — 24 types
• draft-17 — 23 types
• draft-16 — 27 types
• draft-15 — 26 types
• draft-14 — 33 types
• draft-13 — 33 types
• draft-12 — 32 types
• draft-11 — 29 types
• draft-10 — 26 types
• draft-09 — 26 types
• draft-08 — 26 types
• draft-07 — 25 types

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