A method of managing quality of service in an IP network is provided. The method comprises identifying, at an egress edge node of the network, that congestion is present in one or more routers within the network. Data flows for termination to remove the congestion are selected. At least one flow termination notification is sent from the egress edge node to an ingress edge node of the network, the at least one flow termination notification identifying the selected data flows. Low priority flows from the selected data flows are terminated at the ingress edge node immediately. High priority flows are terminated only if congestion is still present after a predetermined delay period. The delay may be applied in the ingress edge node or the egress edge node. The invention also provides a method for admitting low priority flows into the network only if the network has resources available for a number of high priority flows above a dynamically determined threshold.