This field reports the number of excessive defer packets transmitted on the interface, exposed here as cienaCesPmExtendedTxRxAllTimeBinTxExDeferPkts. On this Ciena CES port's PM data, this is a step up from ordinary TxDeferPkts — it only increments when a frame was deferred so long, because the shared medium stayed continuously busy, that it crossed Ciena's excessive-defer threshold, which points at a badly congested half-duplex or shared segment rather than routine CSMA/CD backoff; 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 excessively-deferred frames in this bin; even 33 is enough to warrant a look, since this class of counter isn't supposed to move under normal operation.