Packet-level integration of fluid TCP models in real-time network simulation

We present a hybrid network traffic model that combines time-stepping fluid model with discrete-event packet-oriented simulation. We propose an integration scheme allowing packet flows to interact with fluid flows within each network queue. Different from previous schemes that require physical division of the virtual network between the fluid model and packet-oriented simulation, our hybrid model allows full integration of the two paradigms making it possible to dynamically change the composition of traffic flows to allow the simulation to keep up with real time. Experiments show that our model provides a good prediction of the network behavior. More important, as we increase the proportion of packet flows, the simulation is capable of capturing more detail of the network traffic behavior at the expense of more computing time. Hence the tradeoff.