This sets the count threshold of ingress framer FIFO overflow events that, within the corresponding alert period, triggers a threshold-crossing alert on this port. Because these overflows occur at the raw ingress hardware buffer before ATM-layer classification, exceeding this threshold on this specific port points to the port's receive hardware being unable to keep pace with the incoming cell rate, distinct from any of the egress-side QoS class congestion issues. A port repeatedly crossing this threshold during peak inbound traffic, even while all four egress QoS classes stay well under their own thresholds, would point to an ingress-side hardware limitation on this specific port rather than downstream congestion.