Per its DESCRIPTION, this Counter64 counts seconds during which the DS3 framing pattern could not be found (Severely Errored Framing). Because this is a lifetime counter that only resets on an explicit clear, a reading here means the DS3 receiver briefly lost frame alignment and had to resynchronize on this DS3 circuit, accumulated over the port's entire service life, not merely since the last reboot. 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.