A process is performed by a controller in a split-architecture network. The controller monitors congestion of traffic groups across the split-architecture network and executes the process to provide delay based data rate control to alleviate congestion of the traffic groups. The process includes configuring an ingress switch and egress switch for each traffic group to collect delay measurement data for data packets of each traffic group as they arrive at the ingress switch and egress switch. The delay measurement data is received from the ingress switch and egress switch of each traffic group. A check is made whether a minimum data packet delay for any traffic group exceeds a defined threshold value. A throttling rate is calculated for each traffic group in the split-architecture network, in response to the defined threshold value being exceeded.