HTTP (Hypertext Transfer Protocol) is an application layer communication protocol. Introduction to HTTP Protocol Versions: HTTP/0.9: Only accepts the GET request method, does not specify a version number in communication, and does not support request headers. Since this version does not support the POST method, clients cannot send much information to the server. HTTP/1.0: The … Read more
1. Basic Concepts The HTTP protocol stands for Hyper Text Transfer Protocol, which is used to transfer hypertext from World Wide Web (WWW) servers to local browsers. HTTP is a protocol based on TCP/IP for transmitting data (HTML files, image files, query results, etc.). HTTP is an object-oriented protocol belonging to the application layer. Due … Read more
Background Previously, we discussed how to publish messages and their corresponding packets; now let’s look at how the packets for subscribing to a topic are structured. SUBSCRIBE – Subscribe to a Topic The client sends a SUBSCRIBE packet to the server to create one or more subscriptions. Each subscription registers one or more topics of … Read more
MQTT Packet Structure In the MQTT protocol, an MQTT packet consists of three parts: Fixed Header, Variable Header, and Payload. (1) Fixed Header. Present in all MQTT packets, indicating the packet type and group class identifier. (2) Variable Header. Present in some MQTT packets, the packet type determines whether the variable header exists and its … Read more
1. Introduction MQTT, which stands for Message Queuing Telemetry Transport, is an ISO standard (ISO/IEC PRF 20922) based on the publish/subscribe paradigm. It was released by IBM. Due to its lightweight, simple, open, and easy-to-implement characteristics, it is very suitable for IoT scenarios that require low power consumption and limited network bandwidth, such as remote … Read more
Click the “Blue WeChat Name” Under the Title to Quickly Follow Networking issues are relatively specialized, but understanding some basic knowledge can be very helpful in troubleshooting simple problems. This article from the technical community, “Illustration of 60 Basic Networking Knowledge Points”, explains some basic knowledge related to networks that can be learned and understood. … Read more
From: Juejin, Author: Ruheng Link: https://juejin.im/post/6844903490595061767 1. TCP/IP Model The TCP/IP protocol model (Transmission Control Protocol/Internet Protocol) includes a series of network protocols that form the foundation of the Internet and is the core protocol of the Internet. The reference model based on TCP/IP divides the protocols into four layers: the Link Layer, Network Layer, … Read more
We often hear the term IP, but what is IP? IP stands for “Internet Protocol”, which is the protocol for interconnecting networks, abbreviated as IP. After understanding IP, let’s talk about what an IP address is. First, let me ask everyone a question: there are tens of millions to over a billion hosts connected to … Read more
Click the blue text above to follow us Resource Sharing Huawei Certification Beginner to Advanced Practical Course ↓ Scan the QR code for practical video lessons ↓ 1. Essential Conditions for Network Troubleshooting Why do we need to discuss essential conditions first? Because the network troubleshooting discussed here is not just about using a small … Read more
Nowadays, whether in security engineering or weak current engineering, the connection with networks is becoming increasingly close. Among the basic knowledge of networks, the ping command is the most frequently used in projects. Generally, we only use its basic functions. Today, let’s take a detailed look at the 7 basic uses of the Ping command, … Read more