Introduction

Abstract

The success of packet-switched internetworks bears the label of the Internet. The Internet is driven by rich media types, convergence of computer, communications, broadcast, and telephony industries, and by new business opportunities enabled by these advances. The Internet has seen an extraordinary growth along several dimensions. There are more and more people actually being “on the Internet”. These people come from a growing number of countries, cultures, and different social backgrounds. There is an enormous growth in the number of networks that take part in the Internet. Again, these are very diverse reaching from small home networks operated by Internet-enthusiastic individuals and large corporate or publicly operated networks. Another distinct dimension of growth is with respect to the services and applications which are operated over the Internet ranging from simple electronic mail over sophisticated applications like video-on-demand or video-conferencing to business-critical applications like SAP transactions. Moreover, these applications have vastly different expectations about the services that are provided by the network. While traditional Internet applications like file transfer and electronic mail have rather lax requirements with regard to predictability and robustness of the underlying network service, this does not hold true any more for many of the commercial applications which are emerging. It is evident that the Internet needs to serve a large spectrum of different needs and fulfill very different expectations in order to continue its success story.