This read-only Counter tallies the number of frames discarded because their Service Data Unit size exceeded the maximum permitted size in the egress direction. An administrator monitors this to detect outbound payloads that are simply too large for the connection to carry, distinct from a generic length violation. For example, a rising xmtFramesOversizedSDUs count would suggest an application or device feeding this connection is sending SDUs larger than the connection's configured maximum, warranting an MTU or fragmentation review.