Clean Start and Session Expiry Interval - MQTT 5.0 new features
MQTT 5.0 Clean Start and Session Expiry Interval not only solve the legacy problems of Clean Session, but also extend the usage scenarios of the client.
Reason code and ACK - MQTT 5.0 new features
MQTT v3.1.1 protocol has only 10 return codes. These return codes can represent little meaning, and the same return code value can have different meanings in different messages.
MQTT 5.0 new features | (1) properties and loads
Compared with MQTT 3.1.1, MQTT 5.0 protocol adds many properties, which are distributed in variable headers and payloads of packet.