MQTT Essentials Series: Main Features and Characteristics

Jul 18, 2024

MQTT Essentials Series

Overview

  • Discussion on main features and characteristics of MQTT
  • Explanation of why MQTT is powerful for IoT

What is MQTT?

  • Internet of Things (IoT) messaging protocol
  • Built upon TCP/IP
  • Minimal overhead, simple, and reliable
  • Designed for communication over unreliable channels (e.g., poor Wi-Fi, mobile network)
  • Ideal for scenarios with frequent connectivity interruptions (e.g., cars driving through tunnels)
  • Easy to implement and use

Characteristics of MQTT

Binary Protocol

  • More efficient for machines compared to text-based protocols (e.g., HTML, HTTP)

Efficiency

  • Built around maximum efficiency
  • Smallest MQTT packet is 2 bytes

Bi-directional Communication

  • Allows data transfer from device to cloud and back

Data Agnostic

  • Protocol is indifferent to the data format
  • Supports various formats (XML, JSON, custom formats, Google Protocol Buffers, even images or video fragments)

Scalability

  • Can support connections for millions of devices
  • Push communication for low latency
  • Enables millisecond latency from device to device over the internet

Built for Constrained Devices

  • Suitable for devices with limited computing power and memory
  • Libraries available for various programming languages (Arduino, Python, Java, C, C#, Go, Rust)

MQTT Technology Stack

  • Requires TCP
  • Common stack: IP -> TCP -> MQTT
  • Uses persistent TCP connections
  • Heartbeat mechanism to handle half-open socket problems
  • Supports TLS for encrypted connections (TCP -> TLS -> MQTT)
  • Benefits from state-of-the-art libraries like OpenSSL

Advantages of Using TCP with MQTT

  • TCP guarantees reliable, ordered, and error-checked packet transfer
  • MQTT leverages these benefits for efficiency

Next Topics

  • In upcoming videos, we'll discuss how MQTT works
  • Focus on publish/subscribe model

Closing

  • Reminder to subscribe for weekly videos (MQTT Monday)
  • Stay tuned for the next video