This field reports the number of excessive collision packets transmitted on the interface, exposed here as cienaCesPmExtendedTxRxTotalStatsBinTxExCollPkts. On this Ciena CES port's PM data, excessive collisions means a frame was dropped outright after 16 consecutive collision/backoff attempts per the 802.3 algorithm, which only happens when the shared or half-duplex segment on this port is thoroughly saturated; 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 excessive-collision drops in this bin; even 45 is enough to warrant a look, since this class of counter isn't supposed to move under normal operation.