This field reports the total number of packets received that were longer than 1518 octets but less than or equal to the MTU (excluding framing bits, but including FCS octets) and were otherwise well formed, exposed here as cienaCesPmExtendedTxRxAllTimeBinOversizePkts. On this Ciena CES port's PM data, these are frames longer than the standard 1518-octet limit but still within this port's configured MTU and otherwise well-formed, so this counter is expected to move if jumbo/tagged frames are provisioned on this port, and unexpected if they aren't; 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 valid oversized frames in this bin; even 54 is enough to warrant a look, since this class of counter isn't supposed to move under normal operation.