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 …