Broker acknowledgement of a connect request.
Client request to connect to a broker.
Graceful disconnect notification.
Keep-alive ping request.
Keep-alive ping response.
QoS 1 publish acknowledgement.
QoS 2 publish complete (part 3 of the QoS 2 handshake).
Publish message (either direction).
QoS 2 publish received (part 1 of the QoS 2 handshake).
QoS 2 publish release (part 2 of the QoS 2 handshake).
Broker subscribe acknowledgement.
Client subscribe request.
Broker unsubscribe acknowledgement.
Client unsubscribe request.
The MQTT control packet type, as carried in the high nibble of the fixed header.
Each member's numeric value is the on-the-wire packet-type code. The codec switches on these to choose an encoder or decoder, so they double as a stable, readable tag for callers.
Since
1.0.0