Congestion Propagation among Routers in the Internet

In recent years, various non-linear phenomena of the Internet have been discovered. For instance, it is reported that the congestion of a router propagates to neighboring routers like a wave. Several researches on the congestion propagation between routers have been performed. However, in these researches, cause of the congestion propagation between routers and condition that the congestion propagation between routers occurs have not been sufficiently investigated. In this paper, we reveal a cause of the congestion propagation between routers, and also investigate under what conditions the congestion propagation between routers is observed. Consequently, we show that the speed of the congestion propagation between routers is affected by the bandwidth and the propagation delay of links, and that the periodicity of the congestion propagation between routers becomes less obvious as the randomness of network traffic increases.