HTTP-CoAP cross protocol proxy: an implementation viewpoint

In recent years there has been growing interest for the vision of a so-called Web of Things, which pursues the access to a wide variety of everyday objects through a regular web browser. We believe that this vision is right now at a key moment in its realization, analogous to the ´90 for the World Wide Web. The Constrained Application Protocol (CoAP), a web protocol optimized for constrained networks and devices, will hopefully help wireless sensor nodes, a.k.a., smart objects, to become active citizens of the web. Indeed, CoAP has been designed to be easily mapped to HTTP. In this paper we discuss the HTTP mapping of CoAP, and we highlight its different facets and issues. We will describe what are the currently open issues, spanning the deployment of an HTTP-CoAP proxy to the security mapping issues. We also share the authors´ experience gained in the design and implementation of two distinct HTTP-CoAP proxies.