MQTT Protocol

"MQTT (Message Queuing Telemetry Transport) is publish-subscribe-based messaging protocol. It works on top of the TCP/IP protocol. It is designed for connections with remote locations where a ""small code footprint"" is required or the network bandwidth is limited. The publish-subscribe messaging pattern requires a message broker. An MQTT system consists of clients communicating with a server, called a ""broker"". A client may be either a publisher of information or a subscriber. Each client can connect to the broker.

Information is organized in a hierarchy of topics. When a publisher has a new item of data to distribute, it sends a control message with the data to the connected broker. The broker then distributes the information to any clients that have subscribed to that topic. The publisher does not need to have any data on the number or locations of subscribers, and subscribers in turn do not have to be configured with any data about the publishers."