Hi bin2,
Thank you for providing more details! HiveMQ Cloud broker is not available to use without encryption. In production it is not secure to use a broker without encrypted connection. Find more info about MQTT security considerations in the following article: Securing MQTT Systems - MQTT Security Fundamentals
- the HiveMQ Cloud broker (free and paid) is only available via encrypted (TLS) connection, port 8883 and 8884 (Web Socket).
- a Self-hosted HiveMQ you can configure both with and without encryption and use any port.
- the Public HiveMQ broker (broker.hivemq.com) is not intended for production use and it is available without encryption on the port 1883 and 1884(Web Socket).
Kind regards,
Dasha from HiveMQ Team