How Does Ethernet Work?

How does Ethernet work? Ethernet networking is the most popular networking protocol today, and even home users encounter it. Do you know how these little cables carry data to all the networked devices in your house?

What is Ethernet?
Basically, Ethernet is both the name for the cable that enables network devices to connect to one another, and the name for the communication protocol that these cables use. When you refer to an Ethernet port, for example, you're referring to the physical port to which the Ethernet cable connects, but you're also referring to the method of communication that the cable uses; it networks via Ethernet protocols. Most modern Ethernet networks consist of Ethernet cards that contain the Ethernet port, Ethernet cables to connect devices and Ethernet routers or hubs to help regulate traffic.

Where Ethernet started.
Ethernet began in a Xerox research center as a way to connect a computer to a printer. Bob Metcalf is the father of Ethernet; he's the man who designed and implemented the physical cabling used in Ethernet, and the communication protocol that Ethernet uses. While that protocol has expanded to encompass modern technologies, it's built on the basic principles that Metcalf created for Ethernet communication back in 1973.

How Ethernet is used.
Ethernet cables are physical cables used to connect to a Local Area Network, or LAN. Ethernet cables traditionally haven't been suitable for travel over long distances, so they're generally used only for a LAN. You probably use Ethernet cables to connect your computers and devices to a router, which then enables connections to the Internet and regulates traffic on the network.

Understanding Ethernet protocols.
Ethernet is a standard protocol that enables devices to communicate with each other. Without Ethernet, you might have a computer trying to speak the equivalent of German to a printer that understands only American sign language. Not only would the language be wrong, but the communication method would also be completely different.

The Ethernet protocol is a standard protocol that's the same for all devices. It enables every device to "talk" to one another using a communication method that they can all understand. The Ethernet protocol makes it possible to add more devices to the network without altering existing devices on the network; you simply plug the cables in and configure the device.

Ethernet addresses.
One unique aspect of Ethernet is the inclusion of Ethernet addresses. Every piece of data that travels over Ethernet includes a source address and a destination address. When another device receives the data, it checks to see whether it's the intended destination address; if not, it ignores the data.

Routing information.
The Ethernet protocol is elegant in the way it handles data routing. Ethernet is designed to enable data to pass freely between devices; avoiding data collisions and ensuring that all of the data is successfully transmitted and "heard." However, when you have too many devices involved in Ethernet networking, the data transfer can get complicated. Routers and bridges help to regulate Ethernet traffic, by regulating the signals sent across the Ethernet.