This sets the count threshold of egress buffer overflow events for VBR2 traffic that, within its alert period, triggers a threshold-crossing alert on this port. As the lowest-priority of the four QoS-class overflow thresholds on this specific port, this is typically the most permissive setting, since VBR2 traffic on this port is expected to absorb more egress contention before the situation is considered alert-worthy. An admin might leave this threshold noticeably higher than the CBR and VBR1 thresholds on this port, reflecting that this traffic class is expected to tolerate more overflow events before an operator needs to get involved.