This field reports the number of packets received by this PM instance, exposed here as cienaCesPmExtendedTxRxStatsBinRxPkts. On this Ciena CES port's PM data, this is the total received frame count regardless of type, the denominator you pair with RxBytes to get this port's average received frame size, which is itself a useful health signal (a sudden drop toward 64 bytes often means something upstream started sending keepalives or small control packets instead of data); and this sits in the currently active extended Tx/Rx interval bin — its sibling StartTime/ClearTime fields mark exactly which window is being counted, so a change here reflects activity happening in the live collection interval, not something already filed away in history. For example, a moderately busy port showing 20,700 frames received for this bin would be a plausible, unremarkable reading.