Ethernet

TLDR

Ethernet is a branching broadcast communication system that carries digital data packets among locally distributed computing stations and serves as the foundation for local networks and loosely coupled multiprocessors, using a passive broadcast medium without central control. Ethernet coordinates access to its shared medium via distributed controlled statistical arbitration and routes packets to destinations through distributed address recognition, with design principles derived from a 100‑node, kilometer‑long coaxial implementation and including a performance‑estimation model and error‑controlled packet protocol.

Abstract

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.