This counts seconds in which the emulated TDM circuit carried over this pseudowire experienced at least one qualifying error, such as a lost or malformed packet affecting playback. Because this is measured on the reconstructed TDM side of the pseudowire rather than on the packet network directly, ES on this PW reflects what the attached TDM equipment actually experienced, which can rise even when the underlying packet counters look only mildly degraded -- and this specific object covers a cumulative counter reset only by an explicit clear rather than on a fixed schedule -- reflecting everything since PM stats were last cleared. For example, since PM counters were last cleared, this pseudowire might show this counter at 200 -- a concrete count the admin can trend against neighboring bins to judge whether the condition it reflects is worsening.