This field reports the total number of packets received that were longer than the MTU (excluding framing bits, but including FCS octets) and were otherwise well formed, exposed here as cienaCesPmExtendedTxRxTotalStatsBinRxLOutRangePkts. On this Ciena CES port's PM data, these are frames that arrived well-formed (good FCS) but longer than this port's configured MTU, so they weren't corrupted in transit — they simply exceed what this interface is currently willing to accept, which typically means either the far end's MTU/jumbo setting doesn't match this port's, or someone is sending frames sized for a jumbo-enabled path that hasn't actually been provisioned here; 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 over-MTU frames in this bin; even 12 is enough to warrant a look, since this class of counter isn't supposed to move under normal operation.