The Ethernet System

Dr. Robert M. Metcalfe invented Ethernet at the Xerox Palo Alto Research Center in the 1970s. It was designed to support research on the “office of the future,” which included one of the world’s first personal workstations, the Xerox Alto. The first Ethernet system ran at approximately 3-Mbps and was known as “experimental Ethernet.” Ethernet is a local are network (LAN) technology that transmits information between computers at speeds of 10 and 100 million bits per second (Mbps). Currently the most widely used version of Ethernet technology is the 10-Mbps twisted-pair variety. The 10-Mbps Ethernet media varieties include the original thick coaxial system, as well as thin coaxial, twisted-pair, and fiber optic systems. The most recent Ethernet standard defines the new 100-Mbps Fast Ethernet system, which operates over twisted-pair and fiber optic media. The Ethernet system consists of three basic elements: 1. The physical medium used to carry Ethernet signals between computers, 2. A set of medium access control rules embedded in each Ethernet interfaces that allow multiple computers to fairly arbitrate access to the shared Ethernet channel, and 3. An Ethernet frame that consists of a standardized set of bits used to carry data over the system. Each Ethernet-equipped computer, also known as a station, operates independently of all other stations on the network; there is no central controller. All station attached to an Ethernet are connected to a shared signaling system, is also called the medium. Ethernet signals are transmitted serially, one bit at a time, over the shared signal channel to every attached station. To send data a station first listens to the channel, and when the channel is idle the station transmits its data in the form of an Ethernet frame.

As for my first reaction is Ethernet is by far the most popular in LAN technologies in use today. From the time of the first Ethernet standard, the specifications and rights to build Ethernet technology have been made easily available to anyone. This openness, combined with the ease of use and robustness of the Ethernet system, resulted in a large Ethernet market and is another reason Ethernet is so widely implemented in the computer industry.

I agree that the Ethernet was designed to be easily expandable to meet the networking needs of a given site. The vast majority of computer vendors today equip their products with 10-Mbps Ethernet attachments, making it possible to link all manner of computers with an Ethernet LAN. As the 100-Mbps standards becomes more widely adopted computers are being equipped with an Ethernet interface that operates at both 10-Mbps and 100-Mbps. The ability to link a wide range of computers using a vendor-neutral network technology is an essential feature for today’s LAN managers. Most LANs must support a wide variety of computers purchased from different vendors, which requires a high degree of network interoperability of that sort that Ethernet provides.

The Ethernet is a network protocol used in many local area networks that broadcast messages across the network and rebroadcast if a collision of message occurs. Collectively, the Ethernet-like LAN are the dominant force in the LAN market and are likely to remain so for a considerable time.