Abstract. The paper deals with conflict control models of data flows on the Internet. The problem is reviewed, its importance is emphasized, and current approaches to its solution are described. For networks with varying data flows and conflicting users (denial-of-service attacks), a new approach to the analysis based on conflict-control models is proposed. A control model for a class of networks with constant window is developed and the existence of the time-optimal solution is shown. The data loss conditions are established and the system stability against some types of attacks is found.

Keywords: modeling Internet, congestion control, TCP algorithm, denial-of-service attack.