Message Queuing Telemetry Transport
MQTT protocol -> publish-subscribe network protocol that transports messages between devices, usually through TCP/IP
Protocol defines 2 network entities:
- message broker -> receives messages from clients and then sends them to any clients subscribed to topic.
- a number of clients ->
<table style="border: 1px solid black;">
<tr>
<th style="border: 1px solid black;">
MQTT un-encrypted port
</th>
<th style="border: 1px solid black;">
MQTT encrypted port
</th>
</tr>
<tr>
<td style="border: 1px solid black;">**1883** </td>
<td style="border: 1px solid black;">**8883** </td>
</tr>
</table>