The number of packets currently queued for transmission on this
port in queue 0.
The numbering of queues indicates the priority of handling the
traffic in that queue, with the higher queue number getting
higher priority. The priority values in packets are mapped to
queues via a priority to queue mapping. The default priority to
queue mapping is as follows:
Priority Queue
value number
7 7
6 6
5 5
4 4
3 3
2 1
1 0
0 2
This mapping allows the default priority value of 0 to map to a
queue which is not the lowest priority queue, allowing traffic
classes to be assigned a lower priority queue than the default.