This gauge reports the memory, in KBytes, occupied specifically by the structures tracking all currently active (fully established) connections. An admin uses this narrower figure, compared against cufwConnResMemoryUsage, to see how much of the firewall's total connection-tracking memory is tied up in fully established sessions versus connections still being set up. For example, if this value accounts for nearly all of the total connection memory usage, the admin knows established sessions -- not half-open or embryonic ones -- are driving memory consumption.