The Azure Event Grid currently has Message Queuing Telemetry Transport (MQTT) v3.1.1 support with the current following limitations:
- QoS2 is not supported
- A publish request with QoS2 fails and closes the connection.
- Message ordering isn't guaranteed.
- If connecting with MQTT Engine, setting the Reordering Timeout to a value greater than zero will make MQTT Engine wait up to the specified number of milliseconds after receiving an out of order message for the expected message to arrive before considering it a failure.
- Keep Alive Maximum is 1160 seconds.