Analysis and control of bifurcation and chaos in averaged queue length in TCP/RED model

摘要

This paper studies the bifurcation and chaos phenomena in averaged queue length in auddeveloped Transmission Control Protocol (TCP) model with Random Early Detectionud(RED) mechanism. Bifurcation and chaos phenomena are nonlinear behaviour in networkudsystems that lead to degradation of the network performance. The TCP/RED model usedudis a model validated previously. In our study, only the average queue size k qud−udisudconsidered, and the results are based on analytical model rather than actual measurements.udThe instabilities in the model are studied numerically using the conventional nonlinearudbifurcation analysis. Extending from this bifurcation analysis, a modified RED algorithmudis derived to prevent the observed bifurcation and chaos regardless of the selectedudparameters. Our modification is for the simple scenario of a single RED router carryingudonly TCP traffic. The algorithm neither compromises the throughput nor the averageudqueuing delay of the system.