This field reports the number of late collision packets transmitted on the interface, exposed here as cienaCesPmExtendedTxRxTotalStatsBinTxLateCollPkts. On this Ciena CES port's PM data, a late collision is detected after the normal slot time has already passed, the textbook symptom of a duplex mismatch (one end full-duplex, the other half) or an oversized shared segment attached to this port; 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 late-collision frames in this bin; even 6 is enough to warrant a look, since this class of counter isn't supposed to move under normal operation.