A Parameter Based Admission Control for Differentiated Services Networks.pdf

A Parameter Based Admission Control for Differentiated Services Networks Markus Fidler? Department of Computer Science Aachen University, Germany fidler@rmatik.rwth-aachen.de Volker Sander? Central Institute for Applied Mathematics Research Centre Ju?lich, Germany v.sander@fz-juelich.de Abstract The Differentiated Services architecture targets at providing scalable network Quality of Service by means of aggregate scheduling. However, the defined framework itself only gives a number of building blocks, which do not constitute services yet. In order to provide well defined services, the composition of the respective traffic aggregates has to be controlled. This is usually the task of the admission control. In this paper, we investigate a scenario, where access to advanced network services is provided by a parameter based admission control, which allows to provide hard Quality of Service guarantees. We address the scenario of a Premium service which provides bandwidth on demand and which in addition allows to give deterministic bounds on the delay. According the reservation-based approach of the Integrated Services architecture, we propose a set of admission control procedure that are part of a particular resource manager such as a Bandwidth Broker. In extending the Network Calculus principles used by the Integrated Services architecture towards aggregate based scheduling, we show how these procedures can provide reasonably tight delay-bounds 1 Introduction The Differentiated Services (DS) architecture [3] is the most recent approach of the Internet Engineering Task Force (IETF) towards network Quality of Service (QoS). DS addresses the scalability problems of the former Integrated Services approach by aggregation of indi- vidual flows to a small number of different traffic classes, for which service differentiation is provided. Packets are identified by simple markings that indicate the respective class. In the core of the network, routers do not need to determine to