Latency is an explicit, and can be an insidious issue associated with distributed interactive simulations, whether legacy simulations, or simulations based on the DIS (Distributed Interactive Simulation) protocol or the HLA (High Level Architecture) and RTI (Run Time Infrastructure) standards. The implementation details of individual simulations, whether located entirely in one room, or whether geographically distributed across a continent, will directly impact the latencies between various elements of the simulation. At SYSTRAN, we have developed a Windows NT based system, called SNAPpy, that seeks to provide tools to both measure and reduce the latency associated with distributed interactive simulations. SNAPpy includes two major sections: an NIU (Network Interface Unit) that is multi-threaded and built on a SMP and Windows NT platform and the SNAP latency measurement section. This paper will review the architecture of SNAPpy, going into specific details about its make-up and performance. Finally, SNAPpy's potential as a translator of legacy simulations into the HLA/RTI domain is described, and we introduce the SNAP-Lite Latency Measurement System, a new SYSTRAN product.
Index Terms:
DIS, DIS-Lite, EVDAS, HLA, NIU, SNAP, SNAPpy, Symmetric Multi-Processor, VR-Link, Windows NT
Citation:
George J. Valentino, Steve T. Thompson, Todd Kniola, Chris J. Carlisle, "An SMP-Based, Low-Latency, Network Interface Unit and Latency Measurement System: The SNAPpy System," dis-rt, pp.62, Second International Workshop on Distributed Interactive Simulation and Real-Time Applications, 1998