This field reports the number of in error packets received on the port, exposed here as cienaCesPmExtendedTxRxTotalStatsBinRxInErrorPkts. On this Ciena CES port's PM data, these are frames the MAC accepted for delivery but flagged with a receive-side error (bad FCS, alignment, or a similar framing fault), so any nonzero movement here on an otherwise up link points at a cabling, optics, or upstream-device problem specific to this port; and this is the running grand-total counter for the extended Tx/Rx PM group, tallied since the bin's own StartTime (in practice since the PM instance was created or last reset), so treat it as a lifetime tally rather than a per-interval number. For example, a healthy port would sit at 0 for in-error frames in this bin; even 18 is enough to warrant a look, since this class of counter isn't supposed to move under normal operation.