MQTT Broker/Server Mosquitto
There are several products as MQTT Broker/Server.
Mosquitto is one of the most favored products by developers,
and this website will test Mosquitto as a base material.
MQTT is located in the application layer in the OSI 7 layer.
First, start by installing Mosquitto.
A brief overview of MQTT → § MQTT 개요, IOT 개발자사이트 | momoiot .
Install Mosquitto from the following link → § https://mosquitto.org/download/