Analysis of the constrained application protocol over quick UDP internet connection transport

Many IoT deployments rely on an access network that is characterized by densely distributed power constrained devices. Power restrictions, in turns, lead to transmission rate limitations and increased bit errors responsible of network packet loss. Among the many technologies available to deal with these issues, the Constrained Application Protocol (CoAP) introduces an efficient session layer mechanism that provides, as the Hypertext Transport Protocol (HTTP), Representational State Transfer (REST) functionality. However, as opposed to HTTP that relies mostly on the transmission of TCP segments, CoAP has been standardized to support both UDP and TCP transport layers. In IoT scenarios, the CoAP transport protocol selection combined with network conditions can greatly affect overall application Quality of Service (QoS). Under HTTP, the Quick UDP Internet Connection (QUIC) protocol has been introduced as a hybrid alternative to TCP. In this paper, we analyze, model and compare the use of QUIC transport against that of both UDP and TCP in the context of CoAP traffic. (C) 2020 Elsevier B.V. All rights reserved.