Congestion Propagation among Routers with TCP Flows

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