Most MOQT control messages contain a session specific Request ID. The Request
ID correlates requests and responses, allows endpoints to update or terminate
ongoing requests, and supports the endpoint's ability to limit the concurrency
and frequency of requests. Request IDs for one endpoint increment independently
from those sent by the peer endpoint. The client's Request ID starts at 0 and
are even and the server's Request ID starts at 1 and are odd. The Request ID
increments by 2 with each FETCH, SUBSCRIBE, REQUEST_UPDATE,
SUBSCRIBE_NAMESPACE, PUBLISH, PUBLISH_NAMESPACE or TRACK_STATUS request.
Other messages with a Request ID field reference the Request ID of another
message for correlation. If an endpoint receives a Request ID that is not valid
for the peer, or a new request with a Request ID that is not the next in
sequence or exceeds the received MAX_REQUEST_ID, it MUST close the session with
INVALID_REQUEST_ID.
§9.1.
Request ID
This is one section of the MoQT specification, rendered per-section for quick reference and citation. The authoritative text is draft-ietf-moq-transport-16 at the IETF.