A gentlemen by the name of Bob Metcalfe realized that he could improve on a system called the Aloha System which arbitrated access to a shared communications channel. He developed a new system that included a mechanism that detects when a collision occurs (collision detect). The system also includes "listen before talk," in which stations listen for activity (carrier sense) before transmitting, and supports access to a shared channel by multiple stations (multiple access). Put all these components together, and you can see why the Ethernet channel access protocol is called Carrier Sense Multiple Access with Collision Detect (CSMA/CD). Metcalfe also developed a much more sophisticated backoff algorithm, which, in combination with the CSMA/CD protocol, allows the Ethernet system to function all the way up to 100 percent load.

In late 1972, Metcalfe and his Xerox PARC colleagues developed the first experimental Ethernet system to interconnect the Xerox Alto. The Alto was a personal workstation with a graphical user interface, and experimental Ethernet was used to link Altos to o

The truth of the matter is that collisions are absolutely normal and expected events on an Ethernet, and simply indicate that the CSMA/CD protocol is functioning as designed. As more computers are added to a given Ethernet, and as the traffic level increases, more collisions will occur as part of the normal operation of an Ethernet.

IV. Ethernet Frame and Ethernet Addresses

A given Ethernet LAN can consist of merely a single cable segment linking some number of computers, or it may consist of a repeater hub linking several such media segments together. Whole Ethernet LANs can themselves be linked together to form extended network systems using packet switching hubs. While an individual Ethernet LAN may typically support anywhere from a few up to several dozen computers, the total system of Ethernet LANs linked with packet switches at a given site may support many hundreds or thousands of machines.

It's unfortunate that the original Ethernet design used the word "collision" for this aspect of the Ethernet medium access control mechanism. If it had been called something else, such as "stochastic arbitration event (SAE)," then no one would worry about the occurrence of SAEs on an Ethernet. However, "collision" sounds like something bad has happened, leading many people to think that collisions are an indication of network failure.

On a network with heavy traffic loads it may happen that there are multiple collisions for a given frame transmission attempt. This is also normal behavior. If repeated collisions occur for a given transmission attempt, then the stations involved begin expanding the set of potential backoff times from which they chose their random retransmission time.

Some common words found in the essay are:
Ethernet LAN, Identifiers OUIs, SAEs Ethernet, Data Delivery, Trip Timing, Let's IP-based, Addresses Computers, Ethernet Ethernet-equipped, Ethernet Addresses, Technology LAN, ethernet system, media segments, ethernet channel, ethernet interface, ethernet lan, access control, round trip, ethernet frame, medium access control, ethernet interfaces, csma/cd protocol, round trip timing, station ip address, ip address 192022, station station ip,
Approximate Word count = 4045
Approximate Pages = 16 (250 words per page double spaced)