Design and Implementation of Flow-Level Simulator for a Network with Heterogeneous Flows

In this paper, we present design and implementation of a flow level network simulator called FSIM+ (fluid based network SIMulator plus) for a network with heterogeneous flows transferred with different transport protocols: TCP, XCP, and UDP. In recent years, flow level network simulators, which can perform significantly faster simulation than conventional packet level network simulators, have been receiving attention. However, existing flow level network simulators can only simulate persistent TCP flows. In this paper, by utilizing fluid models for several transport protocols, a flow level network simulator FSIM+ for a network with heterogeneous flows is designed. Through several experiments using our FSIM+ implementation, we evaluate its effectiveness quantitatively. Both accuracy and effectiveness of FSIM+ are evaluated by comparing with the popular packet level network simulator ns-2. Our findings include that our FSIM+ implementation achieves (1) less than 6% simulation errors in steady-state performance metrics, (2) approximately 10 times faster simulation, and (3) more than 20 times memory efficiency.