IoT Platform is a platform that integrates capabilities such as device management, secure data communication, and message subscription. You can connect a large number of devices to IoT Platform and collect device data to IoT Platform. You can also call API operations of IoT Platform on your business server to send remote commands to devices.
The following figure shows the communication process among IoT Platform, devices, business servers, and clients.
To achieve communication, you must develop devices, IoT Platform servers, databases, and mobile apps. You can use IoT Platform SDK to develop IoT Platform servers. When you develop devices and IoT Platform servers, you must define and process device messages.
The following table describes the upstream and downstream messaging between devices and IoT Platform.
|Upstream messaging||A device establishes a persistent connection with IoT Platform by using the MQTT protocol. Then, the device submits data to IoT Platform by publishing payloads to a topic.|
|IoT Platform forwards data to your Elastic Compute Service (ECS) instance by using an AMQP consumer group.|
|IoT Platform processes submitted device data and then forwards the data to ApsaraDB RDS, Tablestore, or Function Compute by using the data forwarding feature.|
|Downstream messaging||You can send a command by using your mobile app. Then, your ECS instance calls the HTTPS-based Pub API operation to send the command to an IoT Platform topic.|
|IoT Platform sends data to devices by publishing payloads to specified topics. The MQTT protocol is used for communication.|
For more information about device communication, see What is a topic?