Hybrid Model Network Simulation and Its Implementation in NS-2

Hybrid simulation model which combines the fluid model and packet-level simulation together can integrate advantages of the two methods. This paper proposes the frame of the hybrid model based on the fluid model proposed by Vishal Misra, and proposes implementation of the hybrid model within NS-2 in detail. When using the hybrid model, we adopt packet-level simulation for the subnet that needs detailed packet-level information, and adopt fluid simulation for the others; therefore we can speedup the simulation while still knowing detailed information that we need. The key of the model is how to implement the interface between packet-level model and fluid model. We show it particularly in this paper. We design a set of experiments to evaluate performance of our hybrid model. The results show that the hybrid model not only can obtain the transient behavior of TCP flow accurately, but also can shorten the simulation time.