How do you communicate with your IoT hub using the MQTT protocol?

MQTT is an OASIS communications standard for the Internet of Things. It is intended to be a very lightweight publish/subscribe message transport for linking remote devices with a tiny code footprint and low network traffic. MQTT is now utilized in a broad range of sectors, including automotive, manufacturing, telecommunications, oil and gas, and so on. MQTT became the go-to communications protocol for IoT devices throughout the next two decades after its creation. MQTT was adopted as an ISO standard by Oasis in 2014, signaling its global development as an IoT communications technology. MQTT is used in IoT to link millions of devices from many businesses.

Use the MQTT protocol to interact with your Azure IoT hub.

Azure IoT Hub allows devices to interact with IoT Hub device endpoints by utilizing the following methods:

  • MQTT v3.1.1 is running on port 8883.
  • MQTT v3.1.1 through WebSocket, port 443.

Azure IoT Hub is not a full-featured MQTT broker and does not handle all of the MQTT v3.1.1 standard’s features. This article covers how devices may connect with IoT Hub using supported MQTT behaviors. TLS/SSL must be used to protect all device communications with the IoT Hub. As a result, IoT Hub does not support non-secure communications via port 1883.

The Azure IoT hub SDKs include libraries.

The MQTT protocol is used directly. A device can link to an IoT hub through the MQTT protocol using any of the following methods:

Many business and educational networking settings prohibit the MQTT port (8883). If your firewall does not permit you to open port 8883, we propose utilizing MQTT via Web Sockets. MQTT interacts through Web Sockets on port 443, which is almost always open in networking setups. See Using the device SDKs for information on defining the MQTT and MQTT over Web Sockets protocols when using the Azure IoT SDKs.

Role of MQTT protocol in IoT

Let’s take a closer look at the MQTT protocol architecture in IoT, also known as the Pub/Sub model. As we all know, an IoT network is made up of hundreds of millions of small devices known as sensors. These MQTT IoT devices are called ‘clients’ in MQTT jargon.

Clients may be classified into two groups based on whether they transmit or receive data. Clients that send data to other devices are called ‘publishers.’ Clients who get information from publishers are referred to as subscribers.

Subscriber customer machines can subscribe to any topic or sub-topic of information. Hierarchical structures are seen in complex networks for numerous themes and sub-topics.

MQTT uses servers known as IoT MQTT brokers to transport data between clients. MQTT brokers are cloud-based servers from platforms like Amazon Web Services, Microsoft Azure, or Google Cloud. These brokers easily communicate information between publishers and subscribers, disseminating information throughout the IoT network.

MQTT protocols also employ a notion known as Quality of Service (QoS) levels to assure message delivery even when connections between devices are unreliable. There are three levels of QoS in the MQTT protocol:


QoS 0: Also known as “at most once,” this level sends the message only once, with no certainty of delivery. This level is employed when the connections between devices are steady and the note is unimportant.

QoS 1: Also known as “at least once,” the message is transmitted again until the recipient confirms delivery. This level sends crucial communications that must be delivered on time.

QoS 2: Also known as “exactly once,” the communication is only transmitted once in this level. Because guaranteed delivery necessitates technical cooperation between sender and recipient, this level consumes more energy than the other two levels.

How can MQTT be made secure?

The MQTT protocol is not without flaws. It employs the encryption protocols TLS/SSL and has a poor authentication mechanism. However, modern IoT solution providers, such as Airtel IoT, combine telco-grade security with a dedicated private network to assure the safety of every data transfer in your IoT network.


MQTT is an OASIS Internet of Things communications standard (IoT). Oasis adopted MQTT as an ISO standard in 2014. MQTT v3.1 over WebSocket, port 443, or port 8883. IoT Hub does not support non-secure connections via port 1883.

Quality of Service (QoS) levels ensure message delivery even when device connections are inconsistent. If your firewall prevents you from opening port 8883, we recommend using MQ TT over Web Sockets. To transfer data between clients, MQTT employs servers known as IoT MQTT brokers. These brokers are cloud-based servers from services such as Amazon Web Services, Microsoft Azure, and Google Cloud.


You may also like...