AWS IoT Core primarily supports the MQTT protocol for device connections, which is a lightweight messaging protocol ideal for sending and receiving messages across a constrained network. MQTT is designed for high-latency or unreliable networks, making it particularly suitable for IoT devices that may have intermittent connectivity.
The reason MQTT is favored in AWS IoT Core is due to its efficiency in terms of data usage and bandwidth, which is critical for many IoT applications. It allows for publish/subscribe messaging patterns, enabling devices to easily send and receive messages without needing to maintain continuous connections. This is particularly beneficial for environments with many low-power devices that need to conserve battery life.
While other protocols like HTTP/HTTPS and WebSocket can be used in certain scenarios, they are not optimized for the specialized messaging needs of IoT devices. HTTP has a higher overhead, making it less efficient for constant device communication, and WebSocket requires a persistent connection, which may not always be feasible for all devices. FTP is not suitable for this context as it is primarily designed for file transfer rather than real-time messaging or command and control, which are key aspects of IoT communications.
Therefore, MQTT stands out as the most appropriate choice for device connections within AWS IoT Core.