PQL(Priority Queue List) default-queue table.
There are four priority queues:top,middle,normal,bottom.
The priority level of these queues is from high to low.
A type of priority queue is assigned for those packets that do not match any other rule
in each PQL whose number is from 1 to 16. Such queue is the default queue. For
each PQL the default queue may be different. The default queue is normal if other
type of queue is not configured.