Last year Ethernet turned 43 – and it remains one of the most widely-used local area network technologies.
And as far as telecoms history goes, few modern tools have a naming story quite like Ethernet’s.
It all started on May 22, 1973.
While at the Xerox Palo Alto Research Center, Bob Metcalfe wrote a memo detailing the system he had created for interconnecting computer workstations. Metcalfe’s system, which would become Ethernet, made it possible to send data between workstations and to high-speed laser printers.
Metcalfe’s first experimental network – the one of which Ethernet is based – was called the Aloha Network.
Aloha protocol was simple. A single station would send information and then wait for an acknowledgment. If an acknowledgment wasn’t received within a specified amount of time, the station assumed that another station had transmitted a request simultaneously.
This caused a collision.
In the event of a collision, both stations would choose a backoff time at random and then retransmit their packets. You can read about the entire process here.
Metcalfe basically improved on this system by developing a way to detect collisions. Stations would listen for activity before transmitting anything.
Metcalfe basically improved this system by developing a way to detect collisions. Stations would listen for activity before transmitting anything. (And that is why Ethernet channel access protocol is known as "Carrier Sense Multiple Access with Collision Detect.")
This experiment, called the “Alto Aloha Network,” worked like gangbusters.
In 1973, Metcalfe changed the name to “Ethernet.” He did this to make it clear that the system he had created would support any computer, not just Alto’s.
He chose the name based on the word “ether” as a way of describing an essential feature of the system: the physical medium carrying bits to stations.
He thought this was much like the old luminiferous ether was once thought to propagate electromagnetic waves through space.
Poetic, to say the least.