A brief history of computer networks

The development of computer networks has come a long way. All the communication software we use now is undoubtedly realized with the help of computer networks, but do you know the background of the emergence of computer networks? We have now eliminated the phenomenon of information islands, but several years ago, did you know that computer networks can help us connect the world and eliminate information islands? Let's talk about the development process of computer networks.

The Birth of the Internet

The world's first computer came out in 1946. At that time, there was no computer network, so computers could only work individually. Even if two computers were very close to each other, they could only guard their own corner like an introverted child.

After World War II, the United States and the Soviet Union competed for hegemony. For military purposes, the United States established a mysterious department ARPA. This department, at the request of the US Department of Defense, planned to develop a decentralized command system. This system would have many nodes. Whenever some of the nodes were destroyed, the other nodes could still communicate with each other. The project was completed in 1966, and ARPA named it ARPANET. ARPANET is one of the earliest computer networks and it is the predecessor of the Internet.

ARPANET was one of the first computer networks to use packet switching, a system where data communicated is formatted into packets with the address of the destination machine and then sent to be received by the next machine on the network.

The term data packet was coined by Donald Davies in 1965 to describe data transmitted between computers over a network. Data packets play an important role in computer networks. It can be said that data packets are the protagonists of the Internet.

ARPANET was officially launched in 1969. Also in 1969, Steve Crocker of the University of California, Los Angeles (UCLA) published the first RFC paper, which is considered the beginning of the Internet. In the same year, the first network switch realized the first data transmission on ARPANET, marking the official birth of the Internet.

We often quote .rfc at the end of an article or communicate with someone, and he puts forward an idea that he doesn't fully understand, and then you continue to ask him, and he asks you to look up the RFC document yourself (it seems like he is talking about me). This is what I am talking about.

Official explanation: RFC is an official document that describes the methods, behaviors, research or innovations of the Internet and Internet systems.

In simple terms: the official documentation of the Internet Protocol.

The Birth of TCP/IP

Although it is now possible to communicate between several nodes, the number of nodes is only four, which is still relatively small. In addition, the ARPANET had many limitations at the time, such as the inability of different computer networks to communicate with each other. In order to solve this problem, APPA launched a new research project to try to interconnect different computer LANs.

The early ARPANET used a network protocol called NCP, but with the development of the network, as well as the increase in multi-node access and user demand for the network, the NCP protocol can no longer fully support the development needs of ARPANET. In addition, NCP has a very important flaw, which is that it can only be used in the same operating system environment, which means that Windows users cannot communicate with MacOS users and Android users.

Therefore, ARPANET urgently needed a new protocol to replace the NCP protocol that could no longer meet the needs. The burden of this task was given to Robert E. Kahn and Vinton G. Cerf. The theories of these two great gods are unprecedented to this day. So what did these two old professors do? I will just say it briefly: they proposed a new transmission control protocol - TCP (Transmission Control Protocol). These are two very famous scientists in computer networks. Many people call Robert E. Kahn and Vinton G. Cerf the fathers of the Internet. In 1974, the two published a paper titled "Network Communication Protocol for Packet Switching" in the IEEE journal, formally proposing TCP/IP to achieve interconnection between computer networks.

Although we think that the TCP/IP protocol is a great invention, it was not favored by people at that time, and the four-layer model of TCP/IP was relatively simple compared to the seven-layer model proposed by ISO. However, hard work pays off. After four years of continuous improvement, the TCP/IP protocol finally completed the construction of the infrastructure. Finally, in 1983, the Advanced Research Projects Agency of the US Department of Defense decided to phase out the NCP protocol and replace it with the TCP/IP protocol. It took a full ten years from the paper to publication and then to adoption. In 1985, TCP/IP became a component of the UNIX operating system. After that, almost all operating systems gradually supported TCP/IP, and this protocol became mainstream.

Further development

In the early 1980s, ARPANET was a huge success, but schools that did not receive contracts from US federal agencies could not use it. To solve this problem, the National Science Foundation (NSF) began to build the Computer Science Network (CSNet) for college students. CSNet is a protocol layer added on top of other basic networks. It uses the communication capabilities provided by other networks. From the user's perspective, it is also an independent network. CSNet uses centralized control, and all information exchanges are carried out through a repeater.

In 1986, NSF invested in the establishment of supercomputer centers in five universities and formed NSFNET. With the encouragement and funding of NSF, many universities, government agencies and even private research institutions merged their local area networks into NSFNET. From 1986 to 1991, the number of NSFNET subnets increased rapidly from 100 to more than 3,000.

Not only schools joined, but also many academic groups, enterprises, research institutions and even individuals. Internet users were no longer limited to pure computer professionals. New users found that communication between computers was more attractive to them. Therefore, they gradually regarded the Internet as a tool for communication and exchange, rather than just sharing the computing power of NSF's supercomputers.

The Internet is a collection of global information. It is composed of countless subnets, each of which has several computers.

In the early 1990s, the Internet already had a large number of subnets, each of which was responsible for its own construction and operation costs, and these subnets were interconnected through NSFNET. NSFNET connects tens of millions of computers in the United States and has tens of millions of users. It is the most important member network of the Internet. With the expansion and spread of computer networks around the world, networks outside the United States have gradually connected to the NSFNET backbone or its subnets.

1993 was a very important year in the development of the Internet. In this year, the Internet completed all the most important technological innovations so far. The application of WWW - World Wide Web and browsers gave the Internet a refreshing platform: the content people see on the Internet is not only text, but also pictures, sounds, animations, and even movies. The Internet has evolved into a new world where text, images, sounds, animations, movies and other media complement each other, and it has swept the world at an unprecedented speed.

The rapid rise of the Internet has attracted worldwide attention. my country also attaches great importance to the construction of information infrastructure and the connection with the Internet. At present, the information networks that have been built and are being built have a profound impact on the development of my country's science and technology, economy, society and information exchange with the international community.

Internet Development in my country

Although my country's Internet development did not start as early as the United States, my country has the fastest Internet growth rate in the world.

The development of the Internet in my country originated from 1987 to 1993, during which time domestic scientific and technological workers began to come into contact with Internet resources. During this period, a group of scientific research institutes, led by the Institute of High Energy Physics of the Chinese Academy of Sciences, cooperated with foreign institutions to carry out some scientific research projects connected to the Internet, using the Internet's E-mail system through dial-up, and providing international Internet email services for some key domestic universities and scientific research institutions.

In October 1990, my country officially registered the top-level domain name cn with the Internet Information Center, thus opening up Internet e-mail using its own domain name.

In January 1994, the National Science Foundation of the United States accepted my country's request to formally access the Internet. In March 1994, my country was allowed to join the Internet. In early April, at the my country-US Joint Committee on Science and Technology Cooperation, on behalf of the Chinese government, we formally proposed to the National Science Foundation of the United States (NSF) to connect to the Internet, and it was recognized. So far, my country has finally opened up the last link. On April 20, with the NCFC project connected to the Internet international dedicated line, my country has fully contacted the Internet. In May of the same year, my country's networking work was completed. The Chinese government expressed its approval of the Internet entering my country. The domain name of my country's network was finally determined to be cn. This matter was rated as one of the top ten scientific and technological news in my country in 1994 by the Chinese press, and was listed as one of my country's major scientific and technological achievements in 1994 by the National Statistical Bulletin.

Since 1994, my country has realized TCP/IP connection with the Internet, and gradually opened up the full-function service of the Internet; the large-scale computer network project was officially launched, and the Internet entered a period of rapid development in my country. In 1995, my country Telecom established dedicated lines in Beijing and Shanghai, and provided Internet access services to the public through telephone lines, DDN dedicated lines and X.25 networks. In May 1995, the preparation for the construction of the CHINANET national backbone network began. In January 1996, the CHINANET backbone network was completed and officially opened, and the national public computer Internet network began to provide services. It marked that my country's Internet entered a stage of rapid development.

my country has built several nationwide public computer networks, the largest of which are the following:

• China Telecom Internet CHINANET
• China Unicom Internet UNINET
• China Mobile Internet CMNET
• China Education and Research Computer Network CERNET
• China Science and Technology Network CSTNET

It can be found that my country's Internet construction is mainly divided into three stages.

• The first stage was from 1987 to 1993, which is called the enlightenment stage, or the experimental stage. my country began to use the Internet during this stage and carried out scientific research projects and technological cooperation. However, the network application at this stage was limited to e-mail services in a small range.
• The second stage was from 1994 to 1996. This stage was the start-up stage, or the laying stage. During this stage, my country began to build and lay the backbone network and access the Internet. Since then, my country has been officially recognized as a country with Internet. Then, multiple Internet network projects such as ChinaNet, CERnet, and CSTnet were launched nationwide.
• The third stage is from 1997 to the present, during which Internet access was provided nationwide. This stage was a period of rapid development of the Internet in my country.

After entering the 21st century, the CERNET2 test network was opened. The CERNET2 test network connects the three CERNET core nodes in Beijing, Shanghai and Guangzhou at a speed of 2.5 Gbit/s - 10 Gbit/s, which indicates that my country's Internet has reached the international advanced level.

CNNIC (China Internet Network Information Center) publishes the development of my country's Internet every year. Interested friends can query relevant information through www.cnnic.cn.