In the mid-1980s, people use computers independently start sharing files using a modem to connect to other computers. This practice is known as point-to-point, or a dial transmission. This concept is expanded by using the computer as a media center in the dial-up connection. These computers are called floor announcement (bulletin board). The user connects to the floor this message, leave it or take away the message, as well as sent to or download files. The drawback of the system is that there is little communication direction, and only those who know the message about the floor. Additionally, the computer needs a modem floor notification for each connection, while the number of connections increases, the system can not meet the demand. Through the 1950s, 1970s, 1980s, and 1990s, the Ministry of National US department developed the WAN with high reliability, in order to serve military purposes and science. Other communication technologies; points. It allows multiple computers connected together by different paths. The network itself will define the data migration from one computer to another computer like. Instead can only communicate with a computer at a time, it can communicate with multiple computers simultaneously using the same connection. Later, WAN United States Department of Defense has become the Internet.
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