IOANNIS D. MOSCHOLIOS, PHD, is an Associate Professor in the Department of Informatics and Telecommunications, University of Peloponnese, Tripolis, Greece. His research interests include teletraffic engineering, simulation and performance analysis of communication networks, and queueing theory. MICHAEL D. LOGOTHETIS, PHD, is a Professor in the ECE Department of the University of Patras, Greece. His research interests include teletraffic theory/engineering, traffic/network control, and simulation and performance optimization of communications networks.