ANNOUNCE — MoQT draft-10 §8.18.

The publisher sends the ANNOUNCE control message to advertise where the receiver can route SUBSCRIBEs for tracks within the announced Track Namespace. The receiver verifies the publisher is authorized to publish tracks under this namespace.

ANNOUNCE Message {
  Type (i) = 0x6,
  Length (i),
  Track Namespace (tuple),
  Number of Parameters (i),
  Parameters (..) ...,
}

Figure 19: MOQT ANNOUNCE Message

Track Namespace: Identifies a track's namespace as defined in (Section 2.4.1)
Parameters: The parameters are defined in Section 8.1.1.