  This paper investigates the overload problem of a single congested router in
TCP (Transmission Control Protocol) networks. To cope with the congestion
phenomenon, we design a feedback control based on a multiple time-delays model
of the set TCP/AQM (Active Queue Management). Indeed, using robust control
tools, especially in the quadratic separation framework, the TCP/AQM model is
rewritten as an intercon- nected system and a structured state feedback is
constructed to stabilize the network variables. Finally, we illustrate the
proposed methodology with a numerical example and simulations using NS-2
simulator.
