This field reports the total number of packets (including bad packets) received that were between 4096 and 9216 octets in length inclusive (excluding framing bits but including FCS octets), exposed here as cienaCesPmExtendedTxRxHist24HBin4096To9216OctsPkts. On this Ciena CES port's PM data, this is the top jumbo bucket, 4096 up to 9216 octets, the largest frame size this CES platform's PM can classify, so it's the counter to watch if you've provisioned 9000-byte jumbo frames for this port and want to confirm they're actually being used at full size rather than fragmented smaller; and this lives in one of the rotating 24-hour daily history bins for the port's extended Tx/Rx PM group, so it captures a full day's worth of activity that you can compare day-over-day against the other retained daily bins. For example, a moderately busy port showing 404,000 4096-9216-byte jumbo frames for this bin would be a plausible, unremarkable reading.