Modeling Cascading Failures in Congested Internet

Internet is a complex network with the characteristic of self-organized criticality. The cascading dynamics of Internet are presented and two reasons are pointed out, which may cause cascading failures. Different from betweenness centrality, a congestion function to represent the extent of congestion is proposed. By introducing the concept of "delay time", the correlation between permanent removing and non-removing is built. And a new evaluation function of network efficiency based on congestion function is given in order to measure the damage of cascading failures. Moreover some effects of network structure and size, delay time on congestion propagation are also investigated, and cascading process composed of three phases and some factors affecting cascade propagation are uncovered.