A Brief Comparative Analysis on Application Layer Protocols of Internet of Things: MQTT, CoAP, AMQP and HTTP

The standard and real-time communication technology is a sheer prerequisite for the enhancement of Internet of Things (IoT) applications. However, the task of choosing the standard and compelling messaging protocol also known as application layer protocol is challenging, because it depends on the nature of the IoT system and its messaging requirements. In last two decades ample amount of messaging protocols have been developed and used by various organizations based on their needs. Still, not a single out of those is able to fulfil the messaging needs of all types of IoT systems. Messaging protocol is a growing perplexity for the IoT industry; thus, it is very much essential to understand the pros and cons of the widely accepted and emerging messaging protocols for IoT systems to determine their ideal scenarios. Considering the above mentioned needs, this paper tries to do an effective evaluation of the four entrenched messaging protocols MQTT, CoAP, AMQP and HTTP for IoT systems. An effort has been made to give pros and cons of each of these protocols.