Allied Telesis AT-S63 - Manual (Page 306)

Chapter 19: Class of Service (CoS) Commands
306 Section II: Advanced Operations
This command allows you to override the priority level mappings at the
port level by assigning the packets a temporary priority. Note that this
assignment is made when a packet is received on the ingress port and
before the frame is forwarded to the egress port. Consequently, you need
to configure this feature on the ingress port.
For example, you can configure a switch port so that all ingress frames are
assigned a temporary priority level of 5, regardless of the actual priority
levels that might be in the frames themselves, as found in tagged frames.
A temporary priority level applies only while a frame traverses the
switching matrix. Tagged frames, which can contain a priority level, leave
the switch with the same priority level they had when they entered the
switch.
Examples
The following command changes the temporary priority level on ports 5, 8,
and 12 to 5:
set switch port=5,8,12 priority=5
The following command activates the priority override feature on port 6 so
that all ingress tagged packets use the port’s temporary priority level:
set switch port=6 overridepriority=yes