Per its DESCRIPTION, this Counter64 counts seconds during which the DS3 framing pattern could not be found (Severely Errored Framing). Because this row is the short interval still actively filling right now, a reading here means the DS3 receiver briefly lost frame alignment and had to resynchronize on this DS3 circuit, and because the interval has not closed yet, the count will keep climbing until it does and rolls into the history table. For example, a reading of 0 seconds in this bin on this DS3 circuit spiking briefly during a known maintenance window is expected; the same spike with no maintenance scheduled is not.