This Counter64 counts errored seconds for this pseudowire — seconds during the cumulative bin in which at least one error was detected at the PW/service layer. 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, Es (without the trailing 'p') measures errors at the pseudowire/packet-service layer, distinct from the Esp counter in the same table which measures the underlying physical TDM path — comparing the two tells you whether errors are coming from the packet network or the TDM interface itself. For example, if Es is climbing quickly while Esp (the path-layer equivalent) stays near zero, the errors are most likely originating in the packet network carrying the pseudowire rather than in the TDM hardware.