Mathematical Problems in Engineering
Volume 2007 (2007), Article ID 54683, 17 pages
doi:10.1155/2007/54683
Research Article
Suboptimal RED Feedback Control for Buffered TCP Flow Dynamics in Computer Network
School of Information Technology and Engineering (SITE), University of Ottawa, 161 Louis Pasteur, P.O. Box 450, Ottawa K1N 6N5, ON, Canada
Received 24 November 2006; Accepted 5 February 2007
Academic Editor: Semyon M. Meerkov
Copyright © 2007 N. U. Ahmed and X. H. Ouyang. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
We present an improved dynamic system that simulates the behavior of
TCP flows and active queue management (AQM) system. This system can
be modeled by a set of stochastic differential equations driven by a doubly
stochastic point process with intensities being the controls. The feedback
laws proposed monitor the status of buffers and multiplexor of the router,
detect incipient congestion by sending warning signals to the sources. The
simulation results show that the optimal feedback control law from the class of
linear as well as quadratic polynomials can improve the system performance significantly
in terms of maximizing the link utilization, minimizing congestion, packet losses, as well
as global synchronization. The optimization process used is based on random recursive
search technique known as RRS.