This field reports the total number of packets (including bad packets) received that were between 1519 and 2047 octets in length inclusive (excluding framing bits but including FCS octets), exposed here as cienaCesPmExtendedTxRxTotalStatsBin1519To2047OctsPkts. On this Ciena CES port's PM data, this bucket only increments for frames between 1519 and 2047 octets, i.e. just over the classic 1518-byte Ethernet limit, so sustained growth here usually means jumbo or heavily-tagged (Q-in-Q/MPLS) frames are transiting this port, which is fine if jumbo was deliberately enabled end-to-end and a red flag if it wasn't; 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 moderately busy port showing 128,000,000 1519-2047-byte frames for this bin would be a plausible, unremarkable reading.