Allied Telesis AT-S79 - Manual (Page 304)

Chapter 31: Quality of Service (QoS)
304 Section II: Using the Web Browser Interface
priority levels contained within the frames to determine the egress
queue. If Yes, the override is activated and the tagged packets are
stored in the egress queue specified in the Queue column.
3. To change the egress queue where ingress untagged frames received
on a port are to be stored on the egress port, use the pull-down menu
in the QoS Priority column and select the desired queue. The range is
0 (lowest) to 3 (highest). The default is 0. For example, if you select 3
for queue 3 for a port, all ingress untagged packets received on the
port are stored in egress queue 3 on the egress port. (If you perform
Step 3 and override the priority level in ingress tagged packets, this
also applies to tagged packets as well.)
If the selected port is part of a port trunk, all ports in the trunk are
automatically assigned the same egress queue.
4. To configure a tagged port so that the switch ignores the priority tag in
ingress tagged frames, select Enable from the Override column for the
corresponding port.
The default for this parameter is disabled, meaning that the priority
level of tagged frames is determined by the priority level specified in
the frame itself.
5. Click Apply.
Note
The tagged information in a frame is not changed as the frame
traverses the switch. A tagged frame leaves a switch with the same
priority level that it had when it entered.