This question was asked during the webinar titled “Ask Me Anything About MQTT: Take 2” held on October 26. 2021 by Ziggy.
Answer: Each IoT device (MQTT client) will have its own standing MQTT connection. This will be initiated with a CONNECT message to the broker. This CONNECT message will have its own ClientId, Clean Session, Username/Password, Will Message, and KeepAlive. If the connection is established, the IoT device can start to SUBSCRIBE and PUBLISH. Please refer to our blog post to know further details.