<span lang="en">This chapter introduces the principal characteristics of MANETs and shows how these particularities may affect both QoS conditions and QoS management/provisioning systems, and therefore the capabilities of MANETs for properly providing multimedia services. After a deep analysis of different QoS mechanisms at different layers, the authors claim that QoS management cannot be handled only at the network layer or by applying some QoS-aware routing protocols. In fact, any end-to-end QoS provision architecture will demand QoS control mechanisms and information exchange among all the layers. A clear understanding of different proposals aimed at coping with QoS requirements at different layers will not only provide researchers with valuable information for designing better multimedia capable MANETs, but will also assist them in evaluating the need for a unified cross-layer approach in order to optimize the performance of analyzed protocols.</span>

<span lang="en">This paper deals with the management of QoS as perceived by end users in corporate networks. First, we overview some previous results achieved by the research group in the field of estimating and managing the QoS. In this work we accomplished some validation tasks by means of simulation. Going on with the analysis of applicability of the general model to real-world, we propose here to analyze a network scenario that includes an MPLS IP VPN. In this scenario we can take into account all the agents involved in the provision of Internet services and moreover we can carry out a management of QoS in the network.</span>