MQTT, short for Message Queue Telemetry Transport, is a light weight messaging protocol that enables embedded devices with limited resources (CPU, RAM, Battery and etc.) to perform asynchronous communication on a constrained network. As its name implies, it is suited for the telemetry data transport like sensors data, but it can also be used for other purposes such as the Facebook Messenger application for smartphone uses MQTT protocol for the messages exchange between the clients. MQTT was developed by IBM and Eurotech and released the protocol as an open standard and being standardized by OASIS, with the first technical committee meeting held on 26th of March in 2013. OASIS, short for “Organization for the Advancement of Structured Information Standards”, is a global consortium that drives the development, convergence and adoption of open standard.
This introduction chapter will cover the following subjects:
· Architecture: Clients and Broker
· Message: Publish, subscribe and topic
· Topic format
· Quality of service
· Authentication and security
· Message flow