This PerfCounter64 counts Path Failure Counts encountered by an E3/T3 interface in the current bin, i.e. the number of discrete path failure events declared so far. An admin uses this live count of distinct failure events, separate from cumulative errored seconds, to gauge how many times a DS3 circuit has already flapped within the current interval. If e3t3StatsPathFCs already shows 2 events partway through the bin on a DS3 trunk, the admin may dispatch a technician immediately rather than waiting to see if a third failure occurs.