Internet primal–dual congestion control: Stability and applications

This paper studies the stability of the primal–dual algorithm for Internet congestion control with round-trip communication delays. The model is formulated as a time-delayed multivariable control system for a general network, and then is studied by using time-delayed control theory. A necessary and sufficient condition is established for a network with a general topology, and then is further discussed for the representative dumbbell network. The stability condition is applied to the design of FAST TCP and adaptive virtual queue (AVQ) scheme as guideline, which is validated by simulation results.