The Transport Session can be terminated at any point. When native QUIC is used, the session is closed using the CONNECTION_CLOSE frame ([QUIC], Section 19.19). When WebTransport is used, the session is closed using the CLOSE_WEBTRANSPORT_SESSION capsule ([WebTransport], Section 6).
When terminating the Session, the application MAY use any error message and SHOULD use a relevant code, as defined below:
- NO_ERROR (0x0):
-
The session is being terminated without an error.
- INTERNAL_ERROR (0x1):
-
An implementation specific error occurred.
- UNAUTHORIZED (0x2):
-
The client is not authorized to establish a session.
- PROTOCOL_VIOLATION (0x3):
-
The remote endpoint performed an action that was disallowed by the specification.
- INVALID_REQUEST_ID (0x4):
-
The endpoint received a Request ID with an incorrect least significant bit for the sender, or a duplicate Request ID. See Section 10.1.
- DUPLICATE_TRACK_ALIAS (0x5):
-
The endpoint attempted to use a Track Alias that was already in use.
- KEY_VALUE_FORMATTING_ERROR (0x6):
-
The key-value pair has a formatting error.
- INVALID_PATH (0x8):
-
The PATH parameter was used by a server, on a WebTransport session, or the server does not support the path.
- MALFORMED_PATH (0x9):
-
The PATH parameter does not conform to the rules in Section 10.3.1.2.
- GOAWAY_TIMEOUT (0x10):
-
The session was closed because the peer took too long to close the session in response to a GOAWAY (Section 10.4) message. See session migration (Section 3.6).
- CONTROL_MESSAGE_TIMEOUT (0x11):
-
The session was closed because the peer took too long to respond to a control message.
- DATA_STREAM_TIMEOUT (0x12):
-
The session was closed because the peer took too long to send data expected on an open Data Stream (see Section 11). This includes fields of a stream header or an object header within a data stream. If an endpoint times out waiting for a new object header on an open subgroup stream, it MAY send a STOP_SENDING on that stream or terminate the subscription.
- AUTH_TOKEN_CACHE_OVERFLOW (0x13):
-
The Session limit Section 10.3.1.3 of the size of all registered Authorization tokens has been exceeded.
- DUPLICATE_AUTH_TOKEN_ALIAS (0x14):
-
Authorization Token attempted to register an Alias that was in use (see Section 10.2.2).
- VERSION_NEGOTIATION_FAILED (0x15):
-
The client didn't offer a version supported by the server.
- MALFORMED_AUTH_TOKEN (0x16):
-
Invalid Auth Token serialization during registration (see Section 10.2.2).
- UNKNOWN_AUTH_TOKEN_ALIAS (0x17):
-
No registered token found for the provided Alias (see Section 10.2.2).
- EXPIRED_AUTH_TOKEN (0x18):
-
Authorization token has expired (Section 10.2.2).
- INVALID_AUTHORITY (0x19):
-
The specified AUTHORITY does not correspond to this server or cannot be used in this context.
- MALFORMED_AUTHORITY (0x1A):
-
The AUTHORITY value is syntactically invalid.
- TOO_MANY_REQUEST_UPDATES (0x1B):
-
The endpoint received a REQUEST_UPDATE that exceeded the per-stream limit communicated via the MAX_REQUEST_UPDATES Setup Option (Section 10.3.1.7).
An endpoint MAY choose to treat a subscription or request specific error as a session error under certain circumstances, closing the entire session in response to a condition with a single subscription or message. Implementations need to consider the impact on other outstanding subscriptions before making this choice.