This holds the single highest per-interval delta observed for inbound frames discarded across the retained sampling window, i.e. the worst one sampling period recorded, not a running total. For one specific FC port's current error-statistics object, this is the field to check first after an alert fires, since it shows the worst burst within the window even if the average looks unremarkable. For example, a deltaMax of 45 next to a deltaAvg of 2 tells an admin the problem was one sharp spike rather than a steady low-grade issue.