Quality of service (QoS) is one of the biggest challenges facing today’s communications systems. Can the Internet Protocol (IP) model of best-effort service, which is the foundation of the Internet, be adapted to also effectively provide QoS features such as guaranteed latency or bandwidth? The outcome will determine whether IP networks’ domination of data is to be extended to voice and video, with major impact on the telecommunications marketplace. This book clearly and objectively explains the several competing approaches currently contending to serve as the QoS solution for IP networks.

Chapter 1 provides a review of the current best-effort Internet architecture, including such functions as addressing and routing. In chapter 2, the requirements for network QoS are broken down into the component QoS requirements at each hop through the network. QoS networks require routers that can differentially classify, queue, and schedule (CQS) all types of traffic as needed. Chapter 3, on per-hop packet processing, describes various approaches to classification, queue management, and scheduling. These per-hop mechanisms are then applied to provide end-to-end models of QoS, illustrated by the integrated services (IS), differentiated services (DS), and multiprotocol label switching (MPLS) approaches.

Chapter 5 examines methods of sending instructions about the processing required to the hops along the path. The signaling approach for enabling end-to-end QoS is illustrated with the resource reservation protocol (RSVP). Chapters 6 through 8 explain how QoS can be applied to a number of link technologies, including point-to-point protocol (PPP), asynchronous transfer mode (ATM), integrated services digital network (ISDN), asynchronous digital subscriber loop (ADSL), and Ethernet. The final two chapters consider dynamic efficiency and robustness of various schemes and anticipate the evolution of QoS over the next few years.

The book provides clear and objective explanations of the various approaches to QoS. These are illustrated with an adequate number of simple figures. Each chapter is amply supported with references (that are current as of mid-1999) to both RFCs and the research literature. The book can be recommended to networking professionals as an authoritative source on the various approaches to QoS in IP networks.