Introduction to Ethernet

Ethernet is a frame based technology which defines wiring and signaling for the physical layer, and frame formats and protocols for the MAC (Media Access Control, data link layer). Ethernet is mostly standardized as IEEE’s 802.3.

Ethernet, by far is the most widely used LAN standard. Every peer node on the network connected using ethernet has a 48-bit unique MAC address such that each system on the network can be distinguished.

History of Ethernet

Ethernet was originally developed as one of the many pioneering projects at Xerox PARC. The standard was first published on September 30, 1980. It competed with two largely proprietary systems, token ring and ARCNET, but those soon found themselves buried under a tidal wave of Ethernet products. In the process, 3Com became a major company.

The characteristics of typical traffic on actual networks differ from what had been expected before LAN’s became common in ways that favor the simple design of Ethernet. Metcalfe and Saltzer worked on the same floor at MIT’s Project MAC while Metcalfe was doing his Harvard dissertation, in which he worked out the theoretical foundations of Ethernet.