What Is Ethernet?

When networking geeks gather, they often talk about network architecture, which (to give you a definition that would be about a tenth as long as the one you’d get from a networking geek) refers to the hardware components that encompass a network, how those components connect together, and the methods those components use to sendanother. In other words (to give you an even shorter definition), the network architecture is the overall design of the network.

Networking geeks also seem overly fond of inventing new networking architectures, so the computing world has seen its share of designs, from Token Ring to ArcNet to FDDI (Fiber Distributed Data Interface, if you must know). Fortunately, you don’t need to know a thing about any of these architectures. That’s because, in recent years, one networking architecture has come to dominate most of computing, and is in fact universal in the small home and office networks that I talk about in this book. That architecture is called ethernet, and it’s the subject of this chapter. Ethernet technology exists in what network mavens call the physical layer and the data link layer of the networking model. The physical layer deals with the technical specifications of networking hardware, and the data link layer deals with the basic transfer of data from one part of the network to another.
 data from one part of the network to