A method for monitoring data congestion in a computer network with multiple nodes and for controlling data transmission in the computer network. The method includes generating a congestion notification by the node which detects a data congestion and transmitting the congestion notification to the data source which is involved in the data congestion. The method also includes generating in the data source a congestion value which indicates how severe the data congestion is, and storing in a worst case array of the data source those congestion values which indicate the most severe data congestions.