Supported versions

The Alibaba Cloud IoT Platform currently supports MQTT-based connections. Both MQTT versions 3.1 and 3.1.1 are supported. For more information about these protocols, see MQTT 3.1.1 and MQTT 3.1.

Comparisons between IoT Platform based MQTT and standard MQTT

  • IoT Platform supports MQTT packets including PUB, SUB, PING, PONG, CONNECT, DISCONNECT, and UNSUB.
  • Supports cleanSession.
  • Does not support will and retain msg.
  • Does not support QoS 2.
  • Supports the RRPC sychronization mode based on native MQTT topics. The server can call the device and obtain a device response result at the same time.

Security levels

Supports secure connections over protocols such as TLS version 1, TLS version 1.1, and TLS version 1.2.
  • TCP channel plus encrypted chip (ID² hardware integration): High security.
  • TCP channel plus symmetric encryption (uses the device private key for symmetric encryption): Medium security.
  • TCP (the data is not encrypted): Low security.

Topic standards

After you have created a product, all devices under the product have access to the following topic categories by default:

  • /${productKey}/${deviceName}/update pub
  • /${productKey}/${deviceName}/update/error pub
  • /${productKey}/${deviceName}/get sub
  • /sys/${productKey}/${deviceName}/thing/# pub&sub
  • /sys/${productKey}/${deviceName}/rrpc/# pub&sub
  • /broadcast/${productKey}/# pub&sub
Each topic rule is a topic category. Topic categories are isolated based on devices. Before a device sends a message, replace deviceName with the deviceName of your own device. This prevents the topic from being sent to another device with the same deviceName. The topics are as follows:
  • pub: The permission to submit data to topics.
  • sub: The permission to subscribe to topics.
  • Topic categories with the following format: /${productKey}/${deviceName}/xxx: Can be expanded or customized in the IoT Platform console
  • Topic categories that begin with "/sys": The application protocol communication standards established by the system. User customization is disabled. The topic should comply with the Alibaba Cloud Alink protocol.
  • Topic categories with the following format: /sys/${productKey}/${deviceName}/thing/xxx: The topic category is used by gateway and sub-devices. It is used in gateway scenarios.
  • Topic categories that begin with "/broadcast": Broadcast topics
  • /sys/${productKey}/${deviceName}/rrpc/request/${messageId}: Used to synchronize requests. The server dynamically generates a topic for the message ID.  The device can subscribe to topic categories with wildcard characters.
  • /sys/${productKey}/${deviceName}/rrpc/request/+: After a message is received, a pub message is sent to /sys/${productKey}/${deviceName}/rrpc/response/${messageId}. The server sends a request and receives a response at the same time.