Hardware of a network switching device supports quantized congestion notification (QCN) to notify senders of network packets received at the network switching device that the network switching device is experiencing congestion. The hardware is instead programmed to notify a processor of the network switching device of the congestion at an egress queue of the network switching device. The processor receives a congestion notification message (CNM) from the hardware that the hardware has detected the congestion at the egress queue. Responsive to receiving the CNM from the hardware, the processor detects a microburst of the network packets at the egress queue of the network switching device.