<span>The constant evolution in internet technology has made. The internet of things (IoT) to be the center of research fields in computer engineering. This review paper discusses the choice of an application layer protocol in an IoT system integration so first, the paper briefly defines the potential protocols. After that, it opens up a comparison between these protocols according to how they manage their overhead and messages which affects traffic management and thus starts the discussion. The main contribution of this work is the simplification of comparison between session layer protocols in the benefit of IoT applications exclusively. IoT system Standards and platforms are being improved constantly. IoT enables application devices to connect and coordinate their tacks, such applications like healthcare, smart home, and industrial automation. Several protocols have been discussed to provide effective communication for resource-limited devices. However, their traffic management is still a field for researches, to find the optimal protocol choice for different situations. The review collects the results of other works that experimentally compared application layer protocols in the IoT environment and presents the graphical and tabular compression. Finally, the conclusion summarize the choice in different applications.</span>