In this lesson we will cover a brief history of the internet. The internet has its roots in the ARPA Net which was conceived in, 1966 to connect big academic computers together. The first operational ARPA Net nodes came online, in 1969 at UCLA, SRI, UCSB, and Utah. Around the same time, the National Physical Laboratory in the UK also came online. By 1971, there were about 20 ARPANet Nodes, and the first host-to-host protocol. There were two cross country links, and all of the links were at 50 KBPS. Here is a rough sketch of the ARPANet as drawn by Larry Roberts in the late 1960s. You can see the four original Nodes here, as well as some other well known players, such as Berkeley. The MAC project at MIT, BBN, Harvard, Carnegie-Mellon, Michigan, Illinois, Dartmouth, Stanford, and so forth. This is what the ARPANET looked like in the late 1960s. Here’s a picture of the ARPANET in June 1974. And you can see not only some additional networks that have come online, but also a diagram of the machines that are connected at each of the universities. You can also see a connection here between the ArpaNet and MPLnet. Of course, the ArpaNet wasn’t the only network. There were other networks at the time. Sat Net operated over satellite. There were packet radio networks and there were also Ethernet local area network. Work started in 1973 on replacing the original network control protocol with TCP/IP. Where IP was the Internetwork Protocol and TCP was the Transmission Control Protocol. TCP/IP was ultimately standardized from 1978 to 1981 and included in Berkley UNIX in 1981. And on January 1st, 1983 the internet had one of its flag days, where the arbanet transitioned to TCP IP. Now the internet continued to grow, but the number of computers on the internet really didn’t start to take off until the mid 90s. You can see here that around August 1995 there were about 10 million hosts on the internet, and five years later there was an order magnitude of hosts on the internet. More than 100 million. During this period the Internet experienced a number of technical milestones. In 1982. The internet saw the rollout of the domain name system which replaced the host.txt file containing all the world’s machine names with a distributed name lookup system. 1988 saw the rollout of TCP congestion control after the net suffered a series of congestion collapses. 1989 saw the NSF net and BGP inter-domain routing. Including support for routing policy. The 90s, on the other hand, saw a lot of new applications. In approximately 1992, we started to see a lot of streaming media, including audio and video. The Web was not soon after, in 1993, which allowed users to browse a mesh of hyperlinks. The first major search engine was Altavista, which came online in December of 1995, and peer to peer protocols and applications including file sharing, began to emerge around 2000.