Simulation Study of Flood Attacking of DDOS

Distributed denial-of-service (DDOS) attacking remains a great threat to the Internet. The literature regarding qualitative descriptions of DDOS attacking is rich. However, quantitative descriptions are rarely reported. This paper aims at providing our results of five experiments in this regard for flood attacking in the simulation environment with NS2. The results in this paper indicate that the bandwidth may be more easily flooded by UDP-type attacking than by TCP-type one. In addition, by introducing the concepts of attack time and attack intensity, we show that attack time mainly relates to attack intensity. Furthermore, we give the quantitative evidence to show that buffer size plays a role in dealing with attack traffic.