Unresponsive Fairness Attacks In High Bandwidth-Delay Product Networks

The congestion control protocol requires the cooperation of all hosts. It makes sure that the network resources can be utilized effectively and allocated fairly. But a number of malicious hosts do not response the network congestion information and occupy too much unfair bandwidth. The malicious behave can obtain unfair advantages over cooperative hosts, and even lead to the network collapse. The threat of unresponsive attack also exists in the High Bandwidth-Delay Product.Firstly, the thesis analyzes the different attack methods on the explicit control protocol. Simulation results in several protocols show that the unresponsive attack can seriously destroy the fairness and not be aware easily.In the following, a local defending scheme based on fair queue management in router is presented to defend the explicit control protocol against the unresponsive attack. Theoretical analysis and simulations illustrate that the scheme can solve the problem at some degree, but the control effect can not achieve the fairness requirment.A cooperative defending scheme CMAD-XCP (XCP-based Cooperative Malicious Attacker Detection) combined with the characters of explicit control protocol is proposed to promote local defending scheme performance. In CMAD-XCP, the core routers detect the malicious attacker, and the edge routers distinguish and punish the attacker. Simulation results show that CMAD-XCP can drop the malicious packets promptly, guarantee the fair bandwidth allocation and adapt to various network condition. It has good compatibility and Scalability, can easily implement on other explicit control protocols.Finally, the thesis summarizes the current existing open issues, and provides some further interesting directions.