This read-only counter holds the high-word of the count of packets which exceeded this rate limit, meant to be combined with ccarStatFilteredPkts once that 32-bit counter wraps. This mainly becomes relevant on an entry that's chronically over its configured rate limit and therefore accumulating filtered packets fast enough to eventually wrap its own 32-bit counter, itself an indirect sign that the configured rate has been mismatched to actual traffic for a long time. A rate-limit entry left too restrictive for years of steadily growing traffic could eventually wrap ccarStatFilteredPkts, making this overflow value necessary to see the true lifetime count of excess packets.