Nowadays, all sectors utilize devices that are part of the Internet of Things (IoT) for the purpose of connecting and exchanging information with other devices and systems over the Internet. This increases the diversity of devices and their working environments, which, in turn, creates new challenges, such as real-time interaction, security, interoperability, performance, and robustness of IoT systems. To address these, many applications protocols were adopted and developed for devices with constrained resources. This paper surveys communication protocols divided according to their goals along with their merits, demerits, and suitability towards IoT applications. We summarize the challenges of communication protocols as well as some relevant solutions.