How to Set Up MQTT for Monitoring and Controlling Devices Across Multiple Sites and I

[engrezk]

Hello everyone,
I am working on a project where I need to monitor and control multiple devices located across different geographic sites (each site has its own independent internet connection).
I am planning to use MQTT as the main communication protocol and Home Assistant as the central management platform.
Currently, I have Home Assistant running with Mosquitto Broker installed on the same server.
I want to securely and reliably connect all remote devices to this MQTT environment over the internet.
My questions are:

• What are the proper steps to set up MQTT so that each remote device can send and receive data with Home Assistant across different networks?
  
• How can I ensure secure communication (especially since the devices are not on a single local network)?
  

[admin]

1. install home assistant on cloud server.
2. install Mosquitto Broker on the server.
3. enable mqtt port by your cloud server firewall.
4. set Mosquitto Broker IP, Port, user name, password in KCS mqtt config webpage.