Ethernet: The Definitive Guide, 2nd Edition

Chapter 20. Ethernet Performance

“Performance” is an umbrella term that can mean different things to different people. To a network designer, the performance of an Ethernet system can range from the performance of individual Ethernet channels, to the performance of Ethernet switches, to the performance and capabilities of the entire network system.

For the users of a network, on the other hand, performance usually refers to how quickly the applications that they are using over the network respond to their commands. In this case, the performance of the Ethernet system that connects to a user’s computer is only one component in a whole set of entities that must work together to provide a good user experience.

Because this is a book about Ethernet local area networks, we will focus on the performance of the Ethernet channel and the network system. Along the way, we will also show how the performance of the network is affected by a complex set of elements that includes local servers, filesystems, cloud servers, the Internet, and the local Ethernet system, all working to provide application services for users.

The first part of this chapter discusses the performance of the Ethernet channel itself. We will examine some of the theoretical and experimental analytical techniques that have been used to determine the performance of a single Ethernet channel. Later, we discuss what reasonable traffic levels on a real-world Ethernet can look like. We also describe what kinds of traffic measurements ...