Bob Metcalfe

Ethernet

Ethernet is the coaxial-cable LAN co-invented by Metcalfe and Boggs at Xerox PARC in 1973 to link Alto computers to printers and ARPANET. It introduced CSMA/CD—carrier sensing before transmission, plus collision detection and random back-off—to adapt ALOHAnet for wired use. It ran first on November 11, 1973 at 2.94 Mbit/s. A 1980 Xerox report measured 98% throughput under heavy load. It was standardised as IEEE 802.3 in 1983. CSMA/CD does not scale or support modern requirements like QoS or determinism—and was phased out in favour of switched, full-duplex Ethernet.