Return to Publish–subscribe pattern, Publish-subscribe pattern
MQTT (originally an initialism of MQ Telemetry Transport) is a lightweight, publish-subscribe, machine to machine network protocol for message queue/message queuing service. It is designed for connections with remote locations that have devices with resource constraints or limited network bandwidth, such as in the Internet of Things (IoT). It must run over a transport protocol that provides ordered, lossless, bi-directional connections—typically, TCP/IP. It is an open OASIS standard and an ISO recommendation (ISO/IEC 20922).
Historically, the “MQ” in “MQTT” came from the IBM MQ (then 'MQSeries') MQ product line, where it stands for “Message Queue”. However, the protocol provides publish-and-subscribe messaging (no queues, in spite of the name). In the specification opened by IBM as version 3.1 the protocol was referred to as “MQ Telemetry Transport”. Subsequent versions released by OASIS strictly refers to the protocol as just “MQTT”, although the technical committee itself is named “OASIS Message Queuing Telemetry Transport Technical Committee”. Since 2013, “MQTT” does not stand for anything.