Multi-Class Measurement Based Admission Control for a QoS Framework with Dynamic Resource M

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Abstract In the Laboratory of Communications and Telematics (LCT) of the University of Coimbra researchers have developed a novel, adaptive class-based QoS framework (LCT-QoS). In contrast to common, static resource allocation the core concept behind this approach is dynamic resource distribution based on delay and loss measurements as response to varying demand. To further complete this framework, currently research is undertaken to develop an Admission Control (AC) algorithm for resource control on QoS domain edges and the first accomplishment is presented in this article. Incipient we discuss the general need for AC to manage resources and its inherent features. Upon this, we derive an AC algorithm starting with an introduction of LCT-QoS and what it distincts from general queueing modules, i.e. continuous loss and delay measurements as load indicators for adaptive resource distribution, and the general definition of AC. By extensive simulation under various conditions, we scrutinise the latter and disclose general as well as specific shortcomings of the initial onset, which are then consequently tackled by gradual modifications. Finally, we present a Measurement Based Admission Control Algorithm (MBAC) for LCT-QoS, which fulfils user and operator demands on a high level. Keywords: Measurement Based Admission Control, Adaptive QoS, Delay and Loss Measurements.
Multi-Class Measurement Based Admission Control for a QoS Framework with Dynamic Resource Management
Thomas Bohnert1 , Edmundo Monteiro1 March 21, 2006
University of Coimbra Laboratory of Communications and Telematics CISUC/DEI, Polo II, Pinhal de Marrocos, 3030-290 Coimbra, Portugal Phone: +351239790000 Fax: +351239701266 EMail: tbohnert,edmundo@dei.uc.pt WWW: http://cisuc.dei.uc.pt
T. Bohnert, E. Monteiro: MBAC for a Class-based Q
Introduction
The decision about an appropriate dimension of a link between two nodes in a packet switched network can mainly be considered as a trade-off between initial and operational costs, link utilisation and finally the Quality of Service (QoS) a provider aims to offer to its customers. Regarding the first two arguments, Statistical Multiplexing (SMUX) has proven to guarantee high link utilisation along with minimising required costs and has therefore become de facto standard in modern network technology. Although the deployment of SMUX has this advantage, it imposes some vast challenges regarding the last argument, the provisioning of QoS. While in times of average network load QoS parameters like delay and loss are below requested thresholds, these parameters can rapidly trespass those when many flows become active simultaneously. Independent of the applied multiplexing strategy, every approach is doomed to fail if the load is simply overwhelming. In order to guarantee boundaries for QoS parameters in a network with finite resources, an entity which exerts Admission Control (AC) for arriving flows to a common link is mandatory and became subject of extensive research in the past years. In the Laboratory of Communications and Telematics (LCT) at the University of Coimbra (UC) researchers have developed a novel, adaptive QoS framework (LCT-QoS) inspired by the IETF1 Differentiated Service (DiffServ) model [1]. Since the conceptual need of AC is not limited to any QoS architecture research is undertaken to develop an efficient Measurement Based Admission Control (MBAC) algorithm for LCTQoS. As the core design of this architecture is adaptive resource management based on continuous delay and loss measurement at packet level, a MBAC approach, which leverages this state indicators appears to be the natural approach and in this article we presents the results of our investigations. In the residual sections we first present the evolution of MBAC and related work, Sec. 2. In Sec. 3 we introduce the LCT-QoS framework and the MBAC algorithm we deployed. The experimental setup and the evaluation results are presented in Sec. 4. Finally, in Sec. 5 we conclude and indicate possible future research.
1 Internet 2 Plain
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T. Bohnert, E. Monteiro: MBAC for a Class-based QoS Framework
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mathematical models on a high confidence level, typically based on Poisson Models and Erlang formulas, see for example [2]. CAC is classified as Parameter Based AC since the decision is