Applying Parallel Discrete Event Simulation to Network Emulation

Rob Simmonds, Russell Bradford, and Brian Unger. Submitted to The 14th Workshop on Parallel and Distributed Simulation (PADS 2000). Bologna, Italy, May 28-31, 2000.

Abstract: The simulation of wide area computer networks is one area where the benefits of parallel simulation have been clearly demonstrated. These network simulations benefit from parallel execution since it enables each simulation to be completed in the shortest possible time. Here we present a description of a system that uses a parallel discrete event simulator to act as a high speed network emulator. With this, real Internet protocol (IP) traffic generated by application programs running on user work-stations can interact with modelled traffic in the emulator, thus providing a controlled test environment for distributed applications. Parallel execution enables the emulator to simulate large virtual networks and to model traffic interactions that could not be done in real-time sequentially.

The network emulator uses the TasKit conservative parallel discrete event simulation (PDES) kernel. TasKit has been shown to be able to achieve improved parallel performance over existing conservative and optimistic PDES kernels, as well as improved sequential performance over an existing central-event-list based kernel. This paper explains the modifications that have been made to TasKit to enable real-time operation along with the emulator interface that allows the IP network simulation running in the TasKit kernel to interact with real IP clients. Initial emulator performance data is included.

Keywords: Parallel Discrete Event Simulation (PDES), Computer Network Emulation, Conservative Protocol, Critical Channel Traversing, Real-Time Simulation, Internet Protocol (IP).

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