Ethernet

Ethernet

Ethernet is a family of computer networking technologies commonly used in local area networks (LANs) and metropolitan area networks (MANs). It was commercially introduced in 1980 and first standardized in 1983 as IEEE 802.3, and has since been refined to support higher bit rates and longer link distances. Over time, Ethernet has largely replaced competing wired LAN technologies such as token ring, FDDI and ARCHNET.

The original 10BASE5 Ethernet uses coaxial cable as a shared medium, while the newer Ethernet variants use twist pair and fiber optic links in conjunction with hubs or switches. The Ethernet standards comprise several wiring and signaling variants of the OSI physical layer in use with Ethernet.

Systems communicating over Ethernet dividea stream of data into shorter pieces called frames. Each frame contains source and destination addresses, and error-checking data so that damaged frames can be detected and discarded; most often, higher-layer protocols trigger retransmission of lost frames. As per the OSI model, Ethernet provides services up to and including the data link layer.