Dynamic QoS provisioning in DiffServ domains using fuzzy logic controllers

Most work on Differentiated Services (DiffServ) handles Quality of Service (QoS) provisioning on a per node basis, which assumes that this strategy would provide QoS in the entire domain. Nevertheless, this approach could fail in large domains with multiple flow aggregation and unexpected input traffic. Therefore, provisioning techniques should be used to avoid unexpected overloads that result in QoS fluctuations. A proposal using fuzzy controllers to reconfigure DiffServ nodes according to both incoming traffic and the actual QoS is given. However, it is not easy to specify fuzzy rule bases and membership functions that optimize controller performance. Thus, we also propose a methodology to choose fuzzy controller parameters using the Wang-Mendel and genetic algorithms. Finally, we evaluate the performance of this model by simulation of an IP Telephony application in a DiffServ domain.