Attack vulnerability of complex communication networks

The Internet has been studied as a typical example of real-world complex networks. In this brief, we study the traffic performance of the Internet when it encounters a random or intentional attack. Different from previous approaches, the congestion control protocols are considered so that the bandwidth can be reallocated among flows. In this way, cascading breakdown is less likely to happen. The flow rates are adjusted when a node is attacked and out of function. Consequently, the traffic utility and the utilization ratio of bandwidth are affected. We compare the real Internet data with the classic random graph and scale-free network models. The simulated results also show that the ldquorobust yet fragilerdquo property previously observed in the study of cascading failures in the scale-free networks is still valid in this scenario.