This Counter64 counts the number of times this pseudowire's playout (PDV/jitter) buffer filled completely because packets arrived faster than they could be drained into the TDM stream. Because this is the cumulative TdmPwTotalStatistics counter for the pseudowire, tallied since the bin's own start time rather than being reset every short collection interval, overruns force the buffer to discard incoming packets it has no room for, again producing TDM circuit errors — seeing Overrun instead of Underrun points to bursty early arrival rather than late arrival as the cause. For example, Overrun events clustering right after a QoS re-prioritization that let this pseudowire's traffic through faster than before would suggest the jitter buffer needs to be resized for the new, lower-latency path.