Allied Telesis AT-S79, User Manual

Page: 190 / 210

Chapter 19: Quality of Service (QoS)
190 Section II: Using the Web Browser Interface
Configuring CoS
As explained in “QoS Overview” on page 96, a packet received on a port
is placed it into one of four priority queues on the egress port according to
the switch’s mapping of 802.1p priority levels to egress priority queues.
The default mappings are shown in Table 2 on page 97.
You can override the mappings at the port level by assigning a new default
egress queue to a port. Note that this assignment is made 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 stored in egress
queue 3 of the egress port, regardless of the priority levels that might be in
the frames themselves, as found in tagged frames.
Note
The switch does not alter the original priority level in tagged frames.
Frames leave the switch with the same priority level they had when
they entered the switch.
To configure CoS for a port, perform the following procedure:
1. From the Advanced Config menu, select QoS Config and then select
Port Priority .
The Port Priority Configuration page is shown in Figure 54.
Figure 54. Port Priority Configuration Page