MQTT connection requires CONNECT and CONNACK packets. CONNECT initiates the request and server responds with CONNACK indicating connection result.

This blog will introduce each new feature introduced in 5.0 in turn, and use the MQTTX CLI tool to demonstrate how we can use these features in EMQX.

Introduce Maximum Packet Size in MQTT and explore how to ensure the sent MQTT packets are always smaller than the Maximum Packet Size.

Explain what is Subscription Identifier in MQTT and how it works. Demonstrate how to set a Subscription Identifier for subscription through an example.

In this article, we will focus on exploring the available subscription options in MQTT and their usage.

MQTT Topic Alias allows users to reduce the possibly long and repeatedly used topic name to a 2-byte integer, so as to reduce the bandwidth consumption when publishing messages.

We will introduce in detail the specific use of the new features of MQTT X v1.7.0, especially how to use MQTT X to test features of MQTT 5.0.

User Properties are the user-defined properties that allow users to add their metadata to MQTT messages to expand more application scenarios.

MQTT 5.0 adds a new feature enhanced authentication, which includes query/response style authentication can implement bi-directional authentication of the client and broker.

MQTT 5.0 brings many new features, this article will give an introduction to the use of the new feature "flow control" in an easy-to-understand way.

Compared with MQTT 3.1.1, MQTT 5.0 protocol adds many properties, which are distributed in variable headers and payloads of packet.