 Printer EmailThe Internet has evolved from an academic network for data applications such as file transfer and net news, to a global general-purpose network used for a variety of different applications—electronic mail, voice over IP, television, peer-to-peer file sharing, video streaming and many more. The heterogeneity of applications results in rather different application requirements in terms of bandwidth, delay, loss, etc. Ideally, the underlying network supports Quality-of-Service parameters such that applications can request the desired services from the network and do not need to take actions by themselves to achieve the desired communication quality. Initially, the Internet was not designed to support Quality of Service, and only in the last decade have appropriate mechanisms been developed. Those mechanisms operate mainly on the Internet Protocol (IP) level, but also network-specific mechanisms—e.g., targeted to particular wired/wireless access network technologies—are required. The goal of the European 6th Framework Programme (FP6) Integrated Project “End-to-end Quality of Service Support over Heterogeneous Networks” (EuQoS) was to develop, implement and evaluate concepts and mechanisms to support QoS end-to-end, meaning that QoS mechanisms in end systems, access networks, interdomain links and within domains must be supported. The EuQoS project developed an impressive set of innovative solutions and novel scientific ideas to support end-to-end QoS on the Internet. New mechanisms and concepts were designed and implemented in a European-wide distributed testbed. In addition to the rather technical design and implementation work, the project also developed training material introducing basic QoS mechanisms and techniques. Several e-learning modules were developed and are currently being used at several partner universities for teaching on MSc or PhD levels. The significant technical and educational results achieved during the EuQoS project motivated us to use the gained knowledge and experiences of the project partners and write this book on end-to-end QoS in heterogeneous IP networks. The book basically consists of three parts. In Chaps. 1–4, we discuss QoS mechanisms and protocols such as scheduling schemes, QoS architectures, metrics and measurement techniques, traffic engineering and signalling protocols, and the latest standardisation activities. In Chap. 5, we describe related work and recent developments in the area of transport protocols, in particular how TCP can be optimised toward QoS support and fairness. The EuQoS system presented in Chap. 6 extends and combines the basic mechanisms discussed in the previous chapters. We show how a combination of different QoS-enabling mechanisms and protocols can be used and extended to build a comprehensive end-to-end QoS architecture over heterogeneous wired/wireless access networks. To evaluate QoS mechanisms and architectures, appropriate evaluation schemes are required. The two chapters in the appendix describe how simulation—in particular the well-known network simulator ns-2—as well as emulation techniques can be used for tests and evaluations. This book, which is based on the achievements of the EuQoS project, would not have been possible without funding from the European Commission, as well as the tremendous efforts and enthusiasm of all the people involved in the project. Special thanks to Mark Günter for proofreading the text contributions to this book.
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