Network Hardware: The Physical Layer

Networks are organized as layers of technology.

At "rock bottom" is the physical layer. This layer consists of hardware that simply provides the means for raw digital signals to pass from one computer to another.

In 1973, a young researcher at the Xerox Palo Alto Research Center (PARC) named Bob Metcalfe developed network hardware for building smaller-scale networks he called ethernet, which is still the most widely used category of network hardware today. Ethernet is not a brand name; rather, it is a scheme for how network hardware parts can be built to operate together—in the same way that the term "phillips" describes the way screwdrivers and screws must be built in order to work together. Thus, a great variety of companies produce and sell ethernet cards and cables. When you hear the term ethernet, simply understand it as a synonym for "network."

This chapter was written by Jeff Nyhoff and Joel Adams. Copy editing by Nancy Zylstra
©2005 Calvin University (formerly Calvin College), All Rights Reserved

If you encounter technical errors, contact computing@calvin.edu.