What is the physical technology of the Internet?
Most of the network hardware in the Internet consists of communications lines and switches or routers. In the regional and backbone networks, the lines are mostly leased telephone trunk lines, which are increasingly fiber optic. Routers are computers; indeed, the routers used on the NSFNET are modified commercial IBM RS6000 workstations, although custom designed routers by other companies such as Cisco, Wellfleet, 3-Com and DEC probably have the majority share of the market.
