Internetworking, and New and Proprietary Networks 1972-1980 The initial ARPAnet was a single, closed network. In order to communicate with an ARPAnet host, one had to actually be attached to another ARPAnet IMP. In the early to mid s, additional packet -switching networks besides ARPAnet came into being These architectural principles were embodied in the TCP protocol. The l ALOHAnet, a microwave network linking together universities on the Hawaiian islands l Telenet, a BBN commercial packet -switching network based on ARPAnet technology l Tyrnnet; l Transpac, a French packet -switching network. The number of networks was beginning to grow. In 1973, Robert Metcalfe's PhD thesis laid out the principle of Ethernet, which would later lead to a huge growth in so -called local area networks (LANs) that operated over a small distance based on the Ethernet protocol. Once again, with perfect hindsight one might now see that the time was ripe for developing an encompassing architecture for connecting networks together. Pioneering work on interconnecting networks, once again under the sponsorship of DARPA (Defense Advanced Research Projects Agency) -in essence creating a network of networks -was done by Vinton Cerf and Robert Kahn. The term 'internetting' was coined to describe this work.
