The nomenclature of “MQTT-S” (sensors? security? sausages?) has been confusing to some people, so recently there was a discussion about renaming the protocol to MQTT-SN.
The new name would be MQTT-SN, standing for exactly the same long name, MQTT for Sensor Networks. Some people had assumed that the S in MQTT-S stood for secure, so we hope this change will avoid that confusion.
As part of this change, the copy of the specification now available from the mqtt.org Documentation page now reflects that name change, and links to all previous versions of the specification have been permanently redirected. This is still version 1.2 of the specification, updated to reflect the changed name. MQTT for Sensor Networks is aimed at embedded devices on non-TCP/IP networks, whereas MQTT itself explicitly expects a TCP/IP stack.
So, how can you get started with MQTT-SN? Here’s the exciting part – Really Small Message Broker and Mosquitto are coming together in a new Eclipse project, called Eclipse Mosquitto (here’s the project proposal). The RSMB source code is now available at Eclipse, and it has built-in MQTT-SN support… Ian Craggs shares a very quick getting started guide on his blog. It turns out that Nicholas Humfrey’s tools for MQTT-SN work well with RSMB as well!