UACS Collection of Abstracts 2011 - University American College ...

appearance EUROSIM, Prague, Czech Republic ‐ September 6‐10, 2010Title of the paperAbstractKeywordsJEL classificationIterative System for Simulation of E2E Transport Protocols in HeterogeneousNetworksThe Internet is characterized by the ever‐increasing number of connections,nodes and places of presence, kinds of topologies, transmission mediatechnologies, the yearly growth in user communities by magnitudes, thevariety and the potential of innovative applications, combined with theeconomic, social, cultural and political ramifications. While constantly beingmeasured and evaluated, explored and studied, the Internet is arguablyimpossible to be used for experimentation and investigations in order to testand validate the modifications of the existing network protocols or theintroduction of new ones. Studies are commonly done using laboratoryconditions through tests beds or simulation environments. The ns‐2 networksimulator is a well‐known open source tool extensively used and extendedby the academia, who also needs a standardized set of topologies, traffics,and metrics to validate and verify the results of their efforts. The tcpeval isone of these tools tool designed to provide a standard starting researchframework. The goal of the paper is twofold: using ns‐2 and tcpeval as toolsfor creating a simulation platform enriched with data gathering system andevaluation of the performance of an end‐to‐end transport scheme based onan original TCP modification.Simulation, E2E Protocols, Transport Protocols, ns‐2, tcpeval, HeterogeneousNetworksAuthor(s)Journal of paperappearanceConference of paperappearanceTitle of the paperAbstractMilenkoski Aleksandar, Stojcevska BiljanaInternational Journal of Distributed and Parallel systems (IJDPS) Vol.1, No.1,September 2010Loss Differentiation Algorithms Vs. Congestion Control Schemes: DynamicsAnd PerformanceThis paper carefully analyzes the behavior of different congestion controlschemes when used in combination with Loss Differentiation Algorithm.Three types of congestion schemes are discussed: delay‐based, bandwidthestimation and AIMD, with one TCP variant representing each congestionscheme. We simulated two network scenarios with diverse link and trafficproperties and evaluated the congestion schemes with integrated LossDifferentiation Algorithm in each of them. The integrated LossDifferentiation Algorithm is ideal, i.e. it makes no errors in its judgment. Thebehavior of the schemes is analyzed from aspect of: the properties of theemployed mathematical functions, the effect of presence or absence ofadditional network load (reverse and background traffic), and the achievedthroughput. The results show very diverse scene and pinpoint theimportance of the careful and delicate design of the congestion avoidanceaction when a non‐congestion loss is detected.39