Computer network

This paper is participating in theNetwork protocols must be known and must be known”Essay campaign

About the author

  • The authors introduce

🍓 blog home page: author’s home page 🍓 Introduction: JAVA quality creator 🥇, a junior student 🎓, participated in various provincial and national competitions during school, and won a series of honors

Overview of Computer Networks

This chapter gives a brief introduction to computers, starting with the role of computer networks in the information age. Then it summarizes the Internet, including the three stages of the development of the Internet infrastructure, and the future development trend. Then, the edge and core parts of the Internet are discussed. This paper briefly introduces the development of computer networks in China and the categories of computer networks, and discusses the performance indexes of computer networks. Finally, it discusses the important concept of computer network architecture that will be used throughout the course.

The most important points of this chapter are:

  • The role of the fringe and core parts of the Internet, which include the concept of packet switching.
  • Performance indicators of computer networks.
  • The hierarchical architecture of computer networks, including the concepts of protocols and services. This is a bit abstract. in

Important Concepts in this chapter:

  • The computer network (or network for short) connects many computers together, while the Internet connects many networks together. It is a network of networks.
  • Internet, beginning with the lowercase letter I, is a generic term for a network of interconnected computers. The communication protocols (i.e. communication rules) between these networks can be arbitrary.
  • Internet (Internet), which starts with capital letter I, is a special term. It refers to the world’s largest, open, specific interconnection network connected by many networks, and uses TCP/IP protocol family as communication rules. And its predecessor is American ARPANET. The recommended translation of Internet is “Internet”, but it is rarely used.
  • The Internet now uses store-and-forward packet switching and a three-tier ISP structure.
  • The Internet can be divided into fringe and core parts according to the way it works. A host is an edge part of a network where information is processed. Router is the core part of the network, and its function is to carry out packet switching according to the store-and-forward mode.
  • Computer communication is the communication between processes (that is, running programs) in a computer. The communication modes used in computer network are client server mode and peer to peer connection mode (P2P).
  • Both client and server refer to the application processes involved in communication. The client is the service requester and the server is the service provider.
  • According to the different scope of function, computer networks are divided into WAN, MAN, LAN and PAN.
  • The most commonly used performance indicators of computer networks are: rate, bandwidth, throughput, delay (transmission delay, propagation delay, processing delay, queuing delay), delay bandwidth product, round trip time and channel (or network) utilization.
  • Network protocols are rules established for data exchange on the network. The set of layers and protocols of a computer network is called the network architecture.
  • The architecture of five-layer protocol consists of application layer, transport layer, network layer (or Internet layer), data link layer and physical layer. The most important protocols at the transport layer are TCP and UDP, while the most important protocols at the network layer are IP.

After the language

The original intention of the director to write blog is very simple, I hope everyone in the process of learning less detours, learn more things, to their own help to leave your praise 👍 or pay attention to ➕ are the biggest support for me, your attention and praise to the director every day more power.

If you don’t understand one part of the article, you can reply to me in the comment section. Let’s discuss, learn and progress together!

Wechat (Z613500) or QQ (1016942589) for detailed communication.