What is Computer Networking? What stages has it gone through? 5

According to the geographical location of computer networking, there are generally two types of networks: wide area networks and local area networks.

Internet (Internet, as many people also call it"Internet") are the most typical types of wide area networks, and they usually connect very large areas. China's well-known China Science and Technology Information Network (NCFC), China Public Computer Network (ChinaNet), China Education and Research Network (CERNET) and China Public Economic Information Network (ChinaGBN) all belong to the wide area network.

LAN is currently the most widely used network, for example, the computer network of your institution is a local area network, which we usually call the campus network. LANs also typically provide interfaces to connect to the WAN.

Development of Computer Networks:

1. Computer-terminal.

The geographically dispersed multiple terminal communication lines are connected to a central computer, and users can type programs in the terminals in their own offices, transmit them to the central computer through the communication lines, access and use resources for information processing in a time-sharing manner, and then send the processing results back to the user terminal through the communication lines for display or printing. This single-centric online system is called a remote online system for endpoints.

A simple computer is added before the main machine, which is specially used to process the communication information of the terminal and control the communication line, and can preprocess the user's work, this computer is called"Communication control processors"(CCP: Communication Control Processor), also known as pre-processor; A concentrator is set up in the place where the terminal equipment is concentrated, and the terminal is first gathered on the concentrator through the low-speed line, and then the concentrator is connected to the host computer by the high-speed line.

2. A computer network centered on a communication subnet.

Computers distributed in different locations are interconnected through communication lines to become a computer network. Network users can use the software, hardware and data resources of the local computer through the computer, and can also use other computer software, hardware and data resources in the network to achieve the purpose of resource sharing.

3. Network architecture standardization stage.

ISO developed the OSI RM as the basis for the research and development of a new generation of computer network standards. A variety of remote computer networks, local computer networks, and computer networks in urban areas that comply with OSI RM and protocol standards have begun to be widely used.

4. Network interconnection stage.

Various networks are interconnected to form a larger-scale interconnected network. The Internet is typical, characterized by interconnection, high speed, intelligence, and a wider range of applications.

The formation and development of computer networks has gone through four stages:

The first stage: the combination of computer technology and communication technology forms a primary computer network model. At this stage, the main purpose of network application is to provide network communication and ensure network connectivity.

The network at this stage is still strictly speaking a variant of a multi-user system. Sabbre-1, an aircraft booking system put into operation in the United States in 1963, is a representative of such a system.

The second stage: on the basis of the computer communication network, the computer network with complete network architecture and protocol is realized. The main purpose of the web application at this stage is to:

Provide network communication, ensure network connectivity, network data sharing and network hardware equipment sharing. A milestone in this phase is the ARPANET network of the US Department of Defense. At present, it is often believed that it is the origin of the Internet, and at the same time the origin of the Internet.

The third stage: the computer solves the problem of computer networking and interconnection standardization, and proposes the "Open System Interconnection Reference Model (OSI RM)" in line with the international standard of computer networking, thus greatly promoting the development of computer network technology. At this stage, the network application has developed into the era of information services that provide information sharing services for enterprises.

The representative system is the NSFNET of the National Academy of Sciences in 1985.

The fourth stage: computer networks are developing towards interconnection, high speed, intelligence and globalization, and are rapidly popularized, realizing the wide application of globalization. His masterpiece is the Internet.

It goes through three phases, the details are as follows:

1. The first stage (early 60s to mid-60s). The computer communication network is characterized by the interconnection of the computer and the early coarse terminal to achieve remote access. The first generation of computer networks consisted of hosts, such as communication line terminals, and could only be regarded as the prototype of computer networks.

The first stage of the computer network is a stand-alone system with remote communication function, which solves the problem of multiple users sharing host resources. The terminal is a dumb terminal, which does not have its own CPU, memory, and hard disk, and has no handling capabilities. There is a problem:

The host is burdened and the communication cost is high. It also has a multi-machine system with remote communication function, which solves the problem of heavy burden on the host and expensive communication costs. There is a problem:

Multiple users can share only one host resource.

2. The second stage (mid-60s to mid-70s): the use of packet switching technology to realize the communication between computers, so that the structure and concept of the computer network have changed, and the network structure of the communication subnet and the resource subnet has been formed. The second generation of computer networks is the "formation and development" of computer networks"Stage; The ARPA network in the United States is a representative of the second generation of networks, and the main problem:

The web is not transparent to users.

3. The third stage (mid-70s to late 80s): the stage of modern computer network interconnection, characterized by the formation of network architecture and the standardization of network protocols.

On the basis of the computer communication system, we attach importance to the research of network architecture and protocol standardization, establish unified communication rules for the whole network, use communication protocol software to realize the communication within the network and between the network, and manage the network resources through the network operating system, which greatly simplifies the use of users and makes the computer network provide transparent services to users.

Four stages of development:

The first stage of development: 1946-1956 The era of the tube computer, the first electronic computer came out in 1946 at the University of Pennsylvania in the United States, it was designed by von Neumann, the computing speed was slow and no one was fast, which was a milestone in the history of computer development.

The second stage of development: the computer age of transistors in 1956-1964: the operating system.

The third stage of development: the computer age of integrated circuits and large-scale integrated circuits from 1964 to 1970.

The fourth stage of development: 1970 - the computer age of VLSI circuits.

Inventor of the computer John von Neumann. The computer is one of the most advanced scientific and technological inventions of the 20th century, which has had an extremely important impact on human production and social activities, and has developed rapidly with strong vitality.

The field of application has expanded from the initial military scientific research and application to all fields of society, and has formed a huge computer industry, which has led to technological progress on a global scale, which has triggered profound social changes, and computers have spread all over ordinary schools, enterprises and institutions, and have entered the homes of ordinary people, becoming an indispensable tool in the information society.

An online terminal system centered on a single computer.

Second, the host interconnection centered on the communication subnet.

3. Standardization of computer network architecture.

(1) A telecommunication system based on a single computer.

2) A system in which multiple host computers are interconnected by communication lines (3) A computer network.

A computer network is a structure that follows international standardization protocols and has a unified network system.

Categories: Computer Internet >> Internet.

The development of computer networks has gone through three stages: terminal-oriented single-level computer networks, computer networks-to-computer networks, and open standardized computer networks.