Brief overview of computer network protocols

The foundation of the network is the establishment and application of many computer network protocols. So how can we understand this concept? The following describes the overview of computer network communication protocols. Network Communication Protocol (Network Communication Protocol )) it is a set of definitions of the Information Format for communication between computers and the transfer content that can be received or accepted by both parties. to implement the OSI Layer-7 reference model function, each layer has many communication protocols that are responsible for different aspects and solve different problems, if there are physical interface communication protocols such as RS-232, RS-449 and V.35 in the physical layer), data link protocols such as CSMA/CD, SDLC and HDLC ), the network layer has many routing layer protocols such as IP, RIP, OSPF, and IGRP), while the transport layer has many transmission control protocols such as TCP, FTP, and TFFP ), similarly, the Session Layer, presentation layer, and application have many corresponding network protocols, such as POP3, SMTP, SNMP, and DNS at the application layer ). that is, with the combined use of many communication protocols, the layer-7 model of the network can work properly and ensure that the network communication works normally.

Classification of computer network protocols

Network protocols are a special software and the most basic mechanism for computer networks to implement their functions. network protocols are essentially rules that must be followed by a variety of hardware and software. however, the network protocol is not a set of independent software, which is usually integrated in other software systems. network protocols are deployed at all layers of the OSI communication model. From the familiar TCP/IP, HTTP, and FTP protocols to OSPF, IGP, and other advanced routing protocols, they can all be considered as network protocols, there are thousands of types.

Among all common network protocols, common basic protocols and common application protocols can also be divided. TCP/IP, IPX, SPX, and NetBEUI are common basic protocols, while HTTP, PPP, and FTP are common application protocols. basic protocols are used to provide network connection services, which are essential for network connection and communication activities. application-oriented protocols are not required for networks, but are required only when they are applied to network services. for example, the HTTP protocol is only required for Internet applications, and the FTP protocol is only used for file transfer activities.

Functions and composition of network protocols

The main roles of network protocols and the applicable application environments are different. Some are dedicated. For example, IPX/SPX is dedicated to the NetWare operating system of Novell, the NetBEUI protocol is dedicated to Microsoft's Windows systems, and some are general, of course, relative). For example, the TCP/IP protocol applies to almost all systems and application environments. in so many computer network protocols, network users only need to master several common and main protocols.

The network protocol consists of three parts: semantics, syntax, and timing.

The meaning of the Protocol elements is interpreted. The semantics specified by different types of protocol elements are different. the syntax is to combine several protocol elements and data to express a complete content format, that is, to define the data structure of information. the time sequence is a detailed description of the event Implementation sequence. for example, when both parties communicate, the sending Point sends a data packet. If the target point is correctly received, the source point is correctly received. If an error message is received, the source point is required to be resold once.