Queuing Algorithms Performance against Buffer Size and Attack Intensities in DDOS Attacks

Distributed Denial of Service (DDoS) attack is one of the biggest threats now days. This paper aims at providing the simulation results of buffer size and attack intensities effect on various queuing algorithms such as DropTail, Fair Queuing (FQ), Stochastic Fair Queuing (SFQ), Deficit Round Robin (DRR) and Random Early Detection (RED) using ns-2 as a simulation environment. The results in this paper indicate that Stochastic Fair Queuing is the best algorithms in terms of providing maximum bandwidth to legitimate users against various attack intensities. It is also cleared from simulation results that there is no effect of variation in buffer size on queuing algorithms such as Fair Queuing, Stochastic Fair Queuing and Deficit Round Robin while DropTail and Random Early Detection algorithms are giving the best performance on buffer size 60 against various attack intensities. This paper also covers the basic overview of Denial of Service Attack (DoS), Distributed Denial of Service attack (DDoS), attacking methods, DDoS defense approaches and Queuing Algorithms.