IoT Protocols – MQTT versus CoAP

Abstract

The usage of Internet of Things has increased in the recent years allowing a new way of connecting devices together. Many transactions happen over the IoT calling for protocols to ensure the efficiency and management of the communication traffic. This paper examines 2 particular protocols, Message Queuing Telemetry Transport (MQTT) and Constrained application protocol (CoAP). The main differences between MQTT and CoAP that MQTT runs over TCP and CoAP runs over UDP. MQTT uses three level of QoS to ensure the message delivery while CoAP uses 4 types of transmission attempts which are confirmable, non-confirmable, acknowledgment, and rest. Through a set of experiments, we show that MQTT is more accurate when ensuring packet delivery. However, CoAP is better when it comes to performance when sending a limited number of messages.