Abstract: The invention relates to methods and processes of congestion control for a communication network which may be designed to be compatible with a wide variety of buffer sizing regimes, particularly small buffers, for routers in the network. Each router may include a processor configured to store an internal feedback variable indicative of an aggregate flow rate of all data flows at the router; detect a new data flow to the router; determine any required adjustment to the internal feedback variable and to the flow rates of existing data flows at the router to accommodate the new flow at a defined flow rate; adjust the internal feedback variable, responsive to the determining step; and communicate the defined flow rate to the source of the new flow and the adjusted flow rates to sources of existing data flows.