MOQT uses a pair of unidirectional streams to exchange control messages, as defined in Section 6.3. Every message on a control or request stream is formatted as follows:
MOQT Control Message {
Message Type (vi64),
Message Length (16),
Message Body (..),
}
The following Message Types are defined. The Stream column indicates which stream type each message is sent on: Control indicates the control stream (Section 6.3), and Request indicates a bidirectional request stream. Messages marked "First" MUST be the first message on a new request stream.
| ID | Messages | Stream |
|---|---|---|
| 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 (Section 9.1) | Control |
| 0x10 | GOAWAY (Section 9.2) | Control, Request |
| 0x3 | SUBSCRIBE (Section 9.6) | Request, First |
| 0x4 | SUBSCRIBE_OK (Section 9.7) | Request |
| 0x22 | PUBLISH_STATE_NOTIFY (Section 9.10) | Request |
| 0x1D | PUBLISH (Section 9.8) | Request, First |
| 0x1E | RESERVED (PUBLISH_OK in <= 17) | Request |
| 0xB | PUBLISH_DONE (Section 9.9) | Request |
| 0x16 | FETCH (Section 9.11) | Request, First |
| 0x18 | FETCH_OK (Section 9.12) | Request |
| 0xD | TRACK_STATUS (Section 9.13) | Request, First |
| 0x6 | PUBLISH_NAMESPACE (Section 9.14) | Request, First |
| 0x50 | SUBSCRIBE_NAMESPACE (Section 9.15) | Request, First |
| 0x51 | SUBSCRIBE_TRACKS (Section 9.18) | Request, First |
| 0x8 | NAMESPACE (Section 9.16) | Request |
| 0xE | NAMESPACE_DONE (Section 9.17) | Request |
| 0xF | PUBLISH_SKIPPED (Section 9.19) | Request |
| 0x2 | REQUEST_UPDATE (Section 9.5) | Request |
| 0x7 | REQUEST_OK (Section 9.3) | Request |
| 0x5 | REQUEST_ERROR (Section 9.4) | Request |
An endpoint that receives an unknown message type MUST close the session.
Control messages have a length to simplify parsing, but no control messages
are intended to be ignored. The length is set to the number of bytes in the
Message Body, which is defined by each message type. If the length does not
match the length of the Message Body, the receiver MUST close the session with a
PROTOCOL_VIOLATION.