🎈✨Introduction: 😎Dear friends, as network engineers, do you often feel confused by various protocols? Today, I am here to provide you with a super detailed list of 35 commonly used protocols for network engineers, making it easy for you to master them and no longer feel lost! 👏 Body: 1. – TCP (Transmission Control Protocol): … Read more
Background Keep alive is part of the variable header in the CONNECT message. We have mentioned that the Broker needs to know whether the Client has disconnected abnormally to send the last will message. In fact, the Client also needs to quickly detect if it has lost the connection to the Broker in order to … Read more
Click the blue text aboveto follow us. Resource Release Huawei Certification Beginner to Advanced Practical Course ↓ Scan to watch the practical video ↓ 1. Protocol Layering The TCP/IP protocol uses encapsulation and multiplexing strategies in packet design. Encapsulation means that during the data sending process in the application layer, each layer adds some header … 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
I remember the first time I learned about the global Internet, I wondered what it was really like. When people told me there was a computer network covering almost all of the United States and many places around the world, the first image that came to my mind was a thick cable running along telephone … Read more
Search on WeChat Technical Training Introduction Today, let’s talk about Modbus. First, let’s look at the main content for today: 01 Terminology Interpretation 02 Background 03 Protocol Principles 04 Transmission Methods 05 Differences Between Modbus RTU and Modbus ASCII 06 Modbus TCP and Its Considerations 07 Function Code Functions 08 Modbus Protocol Security Analysis 01 … Read more
/ Network Layered Structure / Consider the simplest case: communication between two hosts. At this point, only a single network cable is needed to connect the two, specifying their hardware interfaces, such as both using USB, 10v voltage, and 2.4GHz frequency. This layer is the physical layer, and these specifications are the physical layer protocol. … Read more
This article is a translation of “Let’s code a TCP/IP stack, 1: Ethernet & ARP”. The translation process is also a learning experience for myself. Writing your own TCP/IP stack may seem like a daunting task. In fact, TCP has accumulated many specifications over its more than thirty years of life. However, the core specifications … Read more
Fact One: File Descriptor Limits Friends who write network server programs in Linux surely know that each TCP connection occupies a file descriptor. Once this file descriptor is exhausted, a new connection attempt will return the error “Socket/File: Can’t open so many files”. At this point, you need to understand the operating system’s limit on … Read more
Click the blue text Follow us In daily life, when shopping online or mailing an item, we need to fill in both parties’ addresses, contact information, whether insurance is needed, and other details. Additionally, the courier company may have other regulations to be added to the purchase and mailing details. The purpose of this is … Read more