Ethernet: Distributed Packet Switching for Local Computer Networks Ethernet is a branching broadcast communication system for carrying digital data packets among locally distributed computing stations. The packet transport mechanism provided by Ethernet has been used to build systems which can be viewed as either local computer networks or loosely coupled multiprocessors. An Ethernet's shared communication facility, its Ether, is a passive broadcast medium with no central control. Coordination of access to the Ether for packet broadcasts is distributed among the contending transmitting stations using controlled statistical arbitration. Switching of packets to their destinations on the Ether is distributed among the receiving stations using packet address recognition. Design principles and implementation are described, based on experience with an operating Ethernet of 100 nodes along a kilometer of coaxial cable. A model for estimating performance under heavy loads and a packet protocol for error controlled communication are included for completeness. CACM July, 1976 Metcalfe, R. M. Boggs, D. R. computer networks, packet switching, multiprocessing, distributed control, distributed computing, broadcast communication, statistical arbitration 3.81 4.32 6.35 CA760704 JB January 4, 1978 12:49 PM 2849 4 2849 2371 5 2849 2849 5 2849 2849 5 2849 2849 5 2849 3032 5 2849 3119 5 2849 2245 6 2849 2798 6 2849 2849 6 2849 2849 6 2849 2859 6 2849