This field reports the number of excessive defer packets transmitted on the interface, exposed here as cienaCesPmExtendedTxRxTotalStatsBinTxExDeferPkts. 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 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 healthy port would sit at 0 for excessively-deferred frames in this bin; even 10 is enough to warrant a look, since this class of counter isn't supposed to move under normal operation.