Mqtt is an asynchronous communication message protocol based on TCP / IP stack, and it is a lightweight publish / subscribe information transmission protocol. Mqtt separates message sender from receiver in time and space, and can be extended in unreliable network environment. It is suitable for the scenarios with limited hardware storage space or limited network bandwidth. The Internet of things platform supports device access using mqtt protocol.

Supported versions

At present, mqtt standard protocol access is supported, compatible with 3.1.1 and 3.1 protocols. For specific protocols, please refer to mqtt 3.1.1 and mqtt 3.1 protocol documents.

Differences from standard mqtt

It supports mqtt’s pub, sub, Ping, pong, connect, disconnect and unsub messages.

Clean session is supported.

Will, retain MSG is not supported.

Qos2 is not supported.

Sub QoS is not supported. Message QoS is subject to the sender (PUB) specification.

Based on the native mqtt topic, RRPC synchronization mode is supported. The server can synchronously call the device and obtain the device receipt result.

Safety level

TCP channel foundation + TLS protocol (tlsv1, tlsv1.1 and tlsv1.2 versions): high security level.

TCP channel foundation + chip level encryption (ID? Hardware integration): high security level.

TCP channel foundation + symmetric encryption (symmetric encryption using device private key): in the security level.

TCP mode (data is not encrypted): low security level.

Topic specification

For topic definition and classification, please check what is topic.

The system default communication topic can go to the console device details page to view, and the function topic can go to the specific function document page to view.