Motivation and Basics

Summary

This chapter provides an introduction to the topic of Quality of Service and motivates the rest of the chapters in the book. The performance of network applications (e.g., video on demand, collaboration tools, voice over IP, Internet TV, video conferencing) depends on the quality of network connections. Parameters such as packet loss, delay, delay variation, and out-of-order delivery are important to describe network performance. Since applications differ in their Quality-of-Service (QoS) needs, this chapter provides a classification of some typical applications and sheds light on their requirements. It further illustrates the implementation and performance of QoS-aware applications, as well as the benefits of such QoS-aware applications, and concludes with a short overview of the following chapters.