Method for operating a packet based data network

A method for operating a packet based data network, the data network comprising a multitude of nodes (A, B, C, D) and a shared data bus, wherein at least some of the nodes (A, B, C, D) add traffic to the data bus, and wherein the upstream nodes (A, B, C, D) reserve data transfer capacity of the data bus for downstream nodes (A, B, C, D) by means of a fairness mechanism, is characterized in that at least some of the nodes (A, B, C, D) drop traffic from the data bus, and that said fairness mechanism takes into account the drop traffic at downstream nodes (A, B, C, D). The inventive method allows a better bandwidth utilization and uses available resources more efficiently.