Message Queuing Telemetry Transport MQTT protocol -> publish-subscribe network protocol that transports messages between devices, usually through TCP/IP

Protocol defines 2 network entities:

1. message broker -> receives messages from clients and then sends them to any clients subscribed to topic.
2. 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>