§9.

Control Messages

Sections

MOQT uses a pair of unidirectional streams to exchange control messages, as defined in Section 3.3. Every message on a control or request stream is formatted as follows:

MOQT Control Message {
  Message Type (vi64),
  Message Length (16),
  Message Payload (..),
}
Figure 3: MOQT Control Message

The following Message Types are defined:

Table 4
ID Messages
0x01 RESERVED (SETUP for version 00)
0x40 RESERVED (CLIENT_SETUP for versions <= 10)
0x41 RESERVED (SERVER_SETUP for versions <= 10)
0x20 RESERVED (CLIENT_SETUP in versions <= 16)
0x21 RESERVED (SERVER_SETUP in versions <= 16)
0x2F00 SETUP (Section 9.4)
0x10 GOAWAY (Section 9.5)
0x7 REQUEST_OK (Section 9.6)
0x5 REQUEST_ERROR (Section 9.7)
0x3 SUBSCRIBE (Section 9.8)
0x4 SUBSCRIBE_OK (Section 9.9)
0x2 REQUEST_UPDATE (Section 9.10)
0x1D PUBLISH (Section 9.11)
0x1E PUBLISH_OK (Section 9.12)
0xB PUBLISH_DONE (Section 9.13)
0x16 FETCH (Section 9.14)
0x18 FETCH_OK (Section 9.15)
0xD TRACK_STATUS (Section 9.16)
0x6 PUBLISH_NAMESPACE (Section 9.17)
0x8 NAMESPACE (Section 9.18)
0xE NAMESPACE_DONE (Section 9.19)
0x11 SUBSCRIBE_NAMESPACE (Section 9.20)
0xF PUBLISH_BLOCKED (Section 9.21)

An endpoint that receives an unknown message type MUST close the session. Control messages have a length to make parsing easier, but no control messages are intended to be ignored. The length is set to the number of bytes in Message Payload, which is defined by each message type. If the length does not match the length of the Message Payload, the receiver MUST close the session with a PROTOCOL_VIOLATION.

This is one section of the MoQT specification, rendered per-section for quick reference and citation. The authoritative text is draft-ietf-moq-transport-17 at the IETF.