This counter records outbound packets that could not be transmitted because of errors. An administrator treats a rising count here as direct evidence of a transmit-side fault on this data link layer, as opposed to the deliberate drops tracked by cntdlOutDiscards. For example, a growing outbound error count alongside cntdot3LanceUnderFlows on the same interface would tell the admin the transmit hardware itself is the likely source of the outbound trouble.