This read-write VlanPriority defines the drop-ineligible priority value used in the Exp-based encoding/decoding scheme on this customer-facing Ethernet traffic port. An administrator sets it to designate which priority level of customer traffic is treated as protected and should not be discarded under congestion. For example, a customer's real-time traffic class on this traffic port would be mapped to this drop-ineligible priority to shield it from discard ahead of best-effort traffic.