One of the most popular protocols to use for Machine-to-Machine (M2M) communication, and the Internet of Things (IoT), is the MQ Telemetry Transport (MQTT) protocol. The MQ refers to IBM's MQ series product line, even though MQTT was not part of that series in the beginning. Since its inception in 1999, the MQTT protocol is implemented in a large array of tools, servers, and libraries in many different languages.

MQTT has drawn interest for various reasons. It is very simple and easy to use, and it is TCP/IP-based. It also includes a new communication pattern that has become popular for efficient distribution of data to multiple consumers: the Publish/Subscribe pattern. That pattern allowed for efficient syndication of news and has become a great tool for efficiently distributing other kinds of information as well, such as sensor data.

Most IP communication patterns before this were focused on either direct asynchronous messaging or the request/response pattern. While it is possible to mass-distribute data using the Internet Group Messaging Protocol (IGMP), on which UDP multicast is based, that method is often very crude, and hence not always suitable for M2M and IoT, which require more detail. IGMP requires a unique IP address for each type of conversation.