MQTT Protocol: Advantages and Disadvantages

This page explores the advantages and disadvantages of the MQTT protocol. It details the benefits and drawbacks of MQTT.

What is MQTT Protocol?

Introduction: As shown, MQTT is a broker-based, lightweight protocol. In this architecture, clients communicate through a central broker. One or more clients can communicate with each other via the broker.

MQTT runs on top of TCP/IP and is therefore connection-oriented. It utilizes a publish/subscribe model for communication.

Key Features of MQTT Protocol:

• It operates over TCP.
• It uses SSL/TLS for security.
• Various messages are used, such as CONNECT, PUBLISH, SUBSCRIBE, DISCONNECT, etc.
• Username/Password authentication is used within the “connect” message.
• It encrypts the payload, meaning it is payload agnostic.
• The default port used by MQTT is 1883.

Benefits or Advantages of MQTT Protocol

The following are the key benefits and advantages of the MQTT protocol:

• The MQTT protocol payload can carry any type of data, including binary and ASCII text. The receiver is responsible for interpreting and decoding the data according to the format used by the transmitter. Hence, MQTT is packet agnostic.
• It uses small packet sizes, making it suitable for low-bandwidth applications.
• It offers lower battery power consumption, which is ideal for IoT devices.
• It is a reliable protocol, utilizing Quality of Service (QoS) options to ensure guaranteed delivery of messages.
• Due to its publish/subscribe model, it is highly scalable, allowing for a large number of connected devices.
• It offers a decoupled design, making it easy to separate devices and servers.
• A publishing device can send data to the server at any time, regardless of the server’s state.

Drawbacks or Disadvantages of MQTT Protocol

Here are the drawbacks and disadvantages of the MQTT protocol:

• MQTT uses the TCP protocol, which can require more processing power and memory compared to other protocols. TCP’s handshake protocol necessitates frequent wake-up and communication intervals, potentially impacting battery consumption. Additionally, TCP-connected devices often keep sockets open for each other, increasing memory and power demands.
• A centralized broker can limit scalability because each client device consumes some overhead. To achieve high scalability, local broker hubs are often employed.
• The centralized broker can become a single point of failure, as client connections to the broker are continuously open.
• Implementation can be more complex compared to simpler protocols like HTTP.
• It doesn’t inherently support advanced features such as flow control, which may need to be implemented separately.
• In MQTT, clients must support TCP/IP, which might not be feasible for all resource-constrained devices.