The ideas of the above architecture are:
- IoT devices should be as simple as possible in order to increase reliability and uptime (here you can see my telecom background)
- SSL/TLS MQTT (Message Queuing Telemetry Transport) is the protocol of choice as it is a secure lightweight publish-subscribe-based messaging protocol (also an ISO standard)
- There should be a secure responsive web interface to be accessed from PC/smartphone
- There should be a secure integration with a voice phone assistant