The Network Grows

By the end of 1969, just four computers were connected to the Arpanet, but the network grew steadily during the 1970s.

In 1972, it added the University of Hawaii’s ALOHAnet, and a year later it added networks at London’s University College and the Norwegian Seismic Array. As packet-switched computer networks multiplied, however, it became more difficult for them to integrate into a single worldwide “internet.”

By the mid-1970s, a computer scientist named Vinton Cerf had begun to solve this problem by developing a way for all of the computers on all of the world’s mini-networks to communicate with one another. He called his invention “Transmission Control Protocol,” or TCP. (Later, he added an additional protocol, known as “Internet Protocol.” The acronym we use to refer to these today is TCP/IP.) One writer describes Cerf’s protocol as “the ‘handshake’ that introduces distant and different computers to each other in a virtual space.”