This read-write VlanPriority defines the drop-eligible priority value used in the Exp-based encoding/decoding scheme on this network port. An administrator sets it to identify which priority level frames are marked as candidates for discard under congestion, distinguishing them from protected, drop-ineligible traffic. For example, best-effort traffic sharing this port with voice traffic would be mapped to this drop-eligible priority so it is dropped first if the network port becomes congested.