MQTT protocol

The MQTT protocol is widely used in the Internet of Things (IoT) due to its lightweight nature for message exchange. It consists of clients and a server, with the server typically being a central hub, and all other participants acting as clients. Clients exchange information through a publish-subscribe mechanism, associating messages with topics. The MQTT server acts as a message broker, forwarding messages between clients.

This publish-subscribe model offers several benefits, the most significant being the decoupling of message senders and receivers. In other words, the person speaking and the person listening do not need to know each other or interact directly. Another advantage is its scalability; adding a device does not require changes to other devices; it only needs to be registered on the server. This mechanism is highly useful in IoT, where communication needs to support message exchange among a large number of devices.

Now, let’s draw a parallel between the MQTT protocol and the banking model. Imagine the MQTT server as a bank, and the devices connected to the MQTT server as bank depositors, borrowers, and companies. Depositors only need to deposit their money into the bank without worrying about who borrows it. Similarly, borrowers only need to borrow from the bank without informing the depositors. This decouples borrowers and depositors. Additionally, those with money to lend for interest do not need to search for borrowers, and those in need of money do not need to search for lenders; they all interact with the bank, which is universally known. MQTT servers typically have public IP addresses, while devices have private IPs, allowing communication between devices with private IPs through a central public IP. From these perspectives, the MQTT protocol does resemble the banking model.

The benefits of a centralized institution include isolating complex relationships through a central entity. However, there are drawbacks: centralized institutions often wield significant power and play crucial roles. For example, the case of Xu Jiayin owing the bank 2.2 trillion and being unable to repay is well-known. Recently, a man in Jiangxi spent 100,000 yuan on 50,000 lottery tickets with the same number, winning 220 million without paying taxes, raising suspicions of collusion with the “Sports Lottery Center.” Fortunately, MQTT servers operate programmatically without human intervention.

In contrast to this centralized model is the decentralized approach of blockchain. Blockchain uses decentralization, encryption, consensus, and distributed storage to ensure data security, transparency, and trustworthiness. It has applications in supply chain management, copyright protection, healthcare, and more.