The development of the Internet can be roughly divided into three stages: the first stage: the development from a single network APPANET to the Internet; the initial shape of the TCP/IP protocol; the first packet switching network ARPANET created by the U.S. Department of Defense in 1969 was initially just a single packet

Switched network (not an interconnected network).

All hosts on the ARPANET to be connected are directly connected to the nearest node switch.

In order to solve this problem, ARPA began to study the interconnection technology of multiple networks (such as packet radio networks), which later led to the emergence of the Internet and became the prototype of the current Internet.

In 1983, the TCP/IP protocol became the standard protocol on ARPANET, allowing all computers using the TCP/IP protocol to communicate using the Internet. Therefore, people regard 1983 as the birth of the Internet.

In 1990, ARPANET officially announced its end because its experimental mission had been completed.

The second stage: building a three-level Internet structure; divided into backbone network, regional network and campus network; after that, U.S. government agencies realized that the Internet will definitely expand its scope of use and should not be limited to universities and research institutions. Later, as the world

Many companies on the Internet have connected to the Internet, causing a sharp increase in the traffic on the network.

So the U.S. government decided to transfer the backbone of the Internet to private companies for operation.

The third stage: the formation of the Internet with a multi-level ISP structure; ISP appears for the first time.

Beginning in 1993, the NSFNET funded by the US government was gradually replaced by several commercial Internet backbones.

A new term has emerged for this purpose: Internet Service Provider, referred to as ISP (Internet Service Provider).

ISPs can apply for multiple IP addresses from Internet management agencies, and also own networking equipment such as communication lines and routers.

Users only need to pay the prescribed fee to the ISP, and then they can obtain the required IP address from the ISP and access the Internet through the ISP.

Extended information Now, many people know the characteristics of the Internet: equality and freedom.

But the United States has always opposed China's joining the Internet.

At the Sino-US High Energy Physics Research Conference in October 1991, US spokesman Walter Toki once again proposed including China into the Internet.

Through Toshi's efforts, the two sides reached an agreement after the meeting: the United States would fund half of the funds needed for China's Internet, and the other half would be provided by the Institute of High Energy at its discretion.

However, the thorny road to the Internet has not become smooth.

At that time, every line connected to Beijing's exits was carefully inspected.

The United States also restricts access to routers exported to China.

After many twists and turns, China finally connected to the Internet in March 1993.

Reference:?Baidu Encyclopedia-Computer Network