This read-only Counter tallies the number of DE-marked frames transmitted by the connection. An administrator tracks this to see how much outbound traffic is being sent already flagged as discard-eligible, which downstream nodes may drop first under their own congestion. For example, a high xmtFramesDE relative to total xmtFrames on a channel means a large share of what this switch is sending out is pre-marked for likely discard if the far end becomes congested.