MOQT defines the .session namespace (the bytes 0x2e, 0x73, 0x65, 0x73,
0x73, 0x69, 0x6f, 0x6e) in the first position of the Track Namespace for
session-level tracks and namespaces. Session-level tracks and namespaces are
managed by the MOQT implementation, not the Application. They provide a
mechanism for extending MOQT transport functionality using existing
subscription and object delivery machinery, without defining new control
messages or stream types.
The Application MUST NOT publish tracks or namespaces whose first
field is .session. Relays MUST NOT forward requests for session-level
tracks and namespaces to other sessions.
The empty track name in the .session namespace is defined to not exist.
A request with a Track Namespace whose first field is .session and an
empty Track Name MUST be rejected with DOES_NOT_EXIST.
An endpoint that receives a request for an unrecognized session-level track or namespace MUST reject it with REQUEST_ERROR using error code DOES_NOT_EXIST rather than passing it to the Application.
The track names and namespaces available under the .session namespace are
defined by extensions to this specification and registered with IANA (see
Section 16.10).