This field reports the number of packet discards on this PM instance, exposed here as cienaCesPmExtendedTxRxAllTimeBinInDiscards. On this Ciena CES port's PM data, these are packets this port discarded despite arriving with no error at all — typically a policy action like an ACL deny, ingress rate-limit, or a full queue — which is a different problem class from the CRC/alignment error counters on this same table; 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 discarded packets in this bin; even 15 is enough to warrant a look, since this class of counter isn't supposed to move under normal operation.