Parallel Simulation and Communication Performance Evaluation of a Multistage BBN Butterfly Interconnection Network for High- Performance Computer Clusters PLAMENKA BOROVSKA, DESISLAVA IVANOVA, PAVEL TSVETANSKI Computer Systems Department Technical University of Sofia 8 Kliment Ohridski Boul., 1000 Sofia BULGARIA pborovska@tu-sofia.bg, d_ivanova@tu-sofia.bg, pavel_tsvetanski@tu-sofia.bg http://cs-tusofia.eu/ Abstract: The communication performance of multistage interconnection networks is a crucial factor influencing the parallel performance of high-performance computer clusters. In this paper we have proposed a methodology for parallelization of an OMNET++ sequential model. We designed in parallel manner a multistage BBN interconnect network topology to meet the demands of efficient and fast communication on high-performance computer systems. The parallel communication are evaluated on the basis of parallel simulation models using the simulation framework OMNET++ (MPI) that is run on IBM HS22 Blade Center at the “High-Performance and GRID Computing Laboratory” located at Computer Systems Department, Technical University of Sofia. Result analysis of parallel simulation results has been performed. Key-Words: High-Speed Interconnection Networks, BBN Network Architecture, OMNET++, Null Message Protocol, Parallel Simulations, Communication Performance Evaluation, Performance Analysis 1 Introduction Interconnection network architecture designs are influenced by next generation high-performance computer clusters and supercomputer technology. The path to next generation Tier-0 computer systems is increasingly dependent on designing computer clusters with hundreds and thousands of processors. The interconnection topology design of a parallel computer system is a critical factor in determining the computer performance. [1-4] Interconnection network designs vary with respect to communication parameters: throughput and latency and cost. Communication network performance determines computer cluster performance for many applications. Therefore, the choice of network architecture has a significant impact on computer performance and will affect the usability of a parallel computer cluster. Interconnection networks are composed of a set of shared switch nodes and links, and the network topology refers to the arrangement of these nodes and links. Selecting the network topology is the first and very important step in designing a network because the flow-control and routing algorithm depend heavily on the network topology design. The goal of this paper is to propose a methodology for parallelization of an OMNET++ sequential model and to evaluate the communication performance of a multistage BBN network design on the basis of program implementation on IBM HS22 Blade Center, located at the “High- Performance and GRID Computing Laboratory”, Technical University of Sofia. Communication performance of a BBN multistage topology is performed by means of network simulations using OMNET++. 2 OMNET++ Platform and Parallel Simulations OMNeT ++ is essentially a set of software tools and libraries that supports the development of simulation models. Most often OMNeT++ is used to develop models of computer networks and protocols. OMNeT++ represents a simulation environment, including specific libraries (simulation framework and library). It is built up of individual components called modules. Its main purpose is to be used for building network simulations of ad-hoc networks, wireless networks, communication networks and others. OMNeT++ includes Eclipse-based graphical development environment (IDE) and some Latest Trends in Applied Informatics and Computing ISBN: 978-1-61804-130-2 237