This field reports the number of packets received with CRC errors by this PM instance, exposed here as cienaCesPmExtendedTxRxAllTimeBinRxCrcErrorPkts. On this Ciena CES port's PM data, a CRC/FCS mismatch means the frame's checksum didn't match its contents by the time it reached this port's MAC, which is a physical-layer signal-integrity symptom — bad cable, dirty connector, marginal optic, or a failing NIC on the far end — not a software or config issue; and this 'all-time' counter for the extended Tx/Rx PM group has no fixed rollover schedule of its own — it just keeps accumulating from whenever the PM instance was last cleared, so a single reading only tells you the running total, not a rate. For example, a healthy port would sit at 0 for CRC-error frames in this bin; even 26 is enough to warrant a look, since this class of counter isn't supposed to move under normal operation.