Research on intrusion tolerance parameters facing DDoS attacks

Based on analysis of the DDoS (distributed denial of service) attack mechanisms, formal deduction of attacking parameters and simulation study of DDoS attack, the paper gives the functional relationship between DDoS attacking effect and impacting parameters, such as network bandwidth, CPU processing ability, memory size, attacking speed, TCP connection buffer size. The systematic requirements to stand DDoS attack which is N times of the CPU processing ability are pointed out. Also, the intrusion-tolerance parameters against DDoS attack are proposed, including CPU processing ability, memory size and TCP connection buffer size. The proposal of these requirements and parameters can greatly improve the ability to defend computer systems against DDoS attack.