This attribute specifies whether the discardPriority applies to DE
frames for this DLCI.
If deDiscardPriority is set to determinedByDiscardPriority, traffic
with DE bit set will be discarded according to the setting of the
discardPriority.
If deDiscardPriority is set to lowest, all traffic with DE bit set will
be treated the same and be sent to the subnet at the lowest discard
priority.