Can you please elaborate on MQTT protocol?
MQTT ( see link MQTT ) is designed as a lightweight protocol for M2M or IoT applications. It targets very lightweight devices with clients typically have a very small code size ). It uses a publish/subscribe model and allows devices to send messages to multiple services or other devices through broker. This is different than the point-to-point HTTP protocol which is intended to allow a client to just communicate with one server at a time.