Quality of service analysis using the Georgia Tech network simulator

We describe a simulation-based quality of service (QoS) analysis we performed using the Georgia Tech network simulator (GTNetS). Our analysis focused on the effects that QoS settings and inline network encryptors (INEs) have on the performance of voice over IP (VoIP) phone calls. We based the simulated network on the network topology used in a joint services military experiment for testing new technology within a joint framework. We illustrate the effect that differing levels of network congestion can have on the performance of VoIP calls. In particular we show that the QoS implementation scheme can have significant impact on the delay seen by VoIP traffic when using INEs. We discuss the need for further analysis of QoS implementation to optimize not only VoIP performance, but also the performance of other-applications intended to run over DoD networks.