On the fairness of flow aggregation for denial-of-service resistant QoS in MANETs.

Mobile ad hoc networks are especially susceptible to denial-of-service attacks due to the lack of infrastructure, the imperfections of the wireless channel, and the limitations of the mobile devices. In principle, providing quality-of-service and resistance against flooding attacks can be achieved with per-flow management. However, a per-flow management scheme makes a mobile device vulnerable to state table exhaustion attacks. To avoid such attacks some degree of flow aggregation is necessary, but such aggregation tends to have a negative impact on flow fairness. We introduce a quantitative metric for the fairness experienced by a flow in the presence of flooding attacks and develop a model to study the impact of flow aggregation on the fairness experienced by a flow in the presence of flooding attacks. We propose a dynamic 3-level flow aggregation scheme, which is able to maintain a high degree of flow fairness even with a relatively small state table size. Our simulation results quantify the impact of flooding attacks on flow fairness and validate the effectiveness of the proposed flow aggregation scheme.