Variable Step Fluid Simulation for Communication Network

We propose a variable step fluid model for communication network in this paper. Our main goal in this research is simulation speedup of a packet-level simulator while maintaining the accuracy. The variable step fluid model not only reduces complexity but also accurately estimates simulation details such as round trip time, queue sizes, TCP windows, and packet drops. In addition, the variable step fluid model reduces event explosions, ripple effects, which have been observed in the traditional fluid models. We validate our model against ns-2 simulation with a mixture of TCP and UDP flows under various background traffic scenarios. Our model achieves significant speedup compared to packetlevel simulators. For example, the speedup of our fluid model for 20 Mb bottleneck is 40 to 70 against ns-2.