This field records how much the counter for carrier-sense errors, i.e. instances where the interface attempted to transmit without first detecting carrier on the medium increased during the most recent collection interval, rather than the lifetime cumulative total. For a network admin, on this Ethernet interface this typically points at a transceiver or physical-layer fault rather than a congestion issue, since carrier detection happens below the point where switching or queuing could interfere. For example, 1 carrier-sense errors in the last interval on this specific FCoE path would already be worth a closer look, since this counter should normally sit at or near zero.