This read-only counter, in frames, tallies frames this switch sent with the DE bit set on this connection, typically because the connection is itself bursting above its committed rate on the way out. A high value here is the outbound mirror of casfVcCountReceivedDEs and flags this particular customer's site as the one oversubscribing, rather than a remote peer. A branch office site persistently sending more than its contracted CIR toward the hub would show a steadily climbing count here on its VC.