Computer Network Technology

Author: Pei Youzhu
Publisher:
Publish Date: 2002-06-01
Features: This book introduces the basic theories and fundamental applications of computer network technology from a brand-new perspective, in a step-by-step and progressive manner. The key content includes the basic knowledge of computer networks, network communication fundamentals, network protocols, network devices, network security management, and network applications. During the writing process, classic theories and new knowledge in computer network technology were carefully selected, with a focus on linking theory with practice. The language and illustrative examples are designed to be as easy to understand as possible. This book is suitable for use as a textbook in secondary vocational education, considering the needs of classroom teaching. Without permission, no part or all of the content of this book may be reproduced or copied in any form. All rights reserved. Infringement will be pursued.
Chapter 1 Overview of Computer Networks
Learning Objectives and Goals of This Chapter, Key Guiding Points:
① Definition of Computer Networks
② Development History of Computer Networks
③ System Composition of Computer Networks
④ Classification of Computer Networks
⑤ Functions and Applications of Computer Networks.
Goals: Master the definition of computer networks; understand the system composition of computer networks; grasp the classification of computer networks; learn the functions and applications of computer networks; understand the development history of computer networks.
Guidance: As an introductory chapter, this chapter begins by helping readers grasp the basic concept of "computer networks" from a conceptual perspective. It primarily introduces the fundamental concepts of computer networks. During learning, it is essential to fully understand the meaning of the definition of computer networks. On this basis, clarify the composition and classification of network systems, and then explore the functions, applications, and development history of computer networks. These are basic knowledge that students in computer and application-related fields should master.
1.1 Definition of Computer Networks
Computer networks are a product of the combination of computer technology and modern communication technology. Due to their rapid development and diverse forms, their definitions have evolved continuously, and different books and literature may present varying perspectives. Currently, it is generally believed that: A computer network is a system that utilizes communication lines to interconnect multiple geographically dispersed, independent computer systems. With the support of corresponding software (such as network operating systems, network protocols, network communication, management, and application software), it enables data communication and resource sharing (resources include hardware, software, etc.). This definition can be understood from the following aspects:
(1) A computer network is a system composed of multiple computer sets. There must be at least two computers in a network, and large networks can accommodate thousands or even tens of thousands of hosts. The most complex and largest network in the world is the Internet, also known as the Internet. These computers can be located in different geographical locations, ranging from a small room to a global scale. The computers in the network have independent functions, meaning there is no master-slave relationship. The startup, operation, and shutdown of one computer are not controlled by any other computer.
(2) For computers in the network to communicate with each other, a channel, i.e., network transmission medium, is required. This can be either wired (e.g., twisted pair cables, coaxial cables, and optical fibers) or wireless (e.g., lasers, microwaves, and communication satellites). Communication equipment refers to devices that transmit data between computers and communication lines according to certain communication protocols. Computers in the network are connected together through specific interconnection devices and communication technologies, which provide the necessary means for data transmission and exchange between computers. Therefore, computers in the network can communicate with each other.
(3) The exchange of information and sharing of resources among computers in the network must be supported by a sound network protocol and software.
(4) Resource sharing refers to the ability of computers in the network to use resources provided by other computer systems, including hardware, software, and data information, etc.