Heterogeneity and Interaction

Abstract

Heterogeneity in network QoS systems comes in manifold forms. Yet, as the only interesting scope of service to the user is a seamless end-to-end communication, these forms of heterogeneity must be mapped into interaction models between the heterogeneous systems. In this chapter, the basic interaction models and components for building heterogeneous QoS systems are introduced and discussed. The central component of interworking between different QoS systems is the edge device. Edge devices are located at the borders between network QoS systems and mediate between the different characteristics and mechanisms of these systems. Very frequently QoS systems are layered on top of each other. This kind of interaction is therefore given special attention in this chapter. Its assumptions and scalability are discussed. At the end, the approach that is taken in the rest of this book is motivated with the background of all the introductory chapters before we advance to concrete problems of interworking QoS systems in the second part of this book.