Nortel Networks 450 - Manual (Page 80)

Using the BayStack 450 10/100/1000 Series Switch
1-54 302401-D Rev 00
Figure 1-35. Port Transmit Queue
As shown in Figure 1-35 , the switch provides two transmission queues, High and
Low, for any given port. Frames are assigned to one of these queues on the basis of
user_priority using a traffic class table. This table is managed by using the Traffic
Class Configuration screen (
Figure 1-36 ). The table indicates the corresponding
traffic class that is assigned to the frame, for each possible user_priority value. If
the frame leaves the switch formatted as a tagged packet, the traffic class assigned
to the frame is carried forward to the next 802.1p capable switch. This allows the
packet to carry the assigned traffic class priority through the network until it
reaches its destination.
The following steps show how to use the Traffic Class Configuration screen to
configure the port priority level shown in
Figure 1-34 .
For more information about using the Traffic Class Configuration screen, see
“VLAN Configuration” on page 3-24.
BS45025A
User priority
(6)
Port
transmit
queue
High
High priority
packet
Port 5
Traffic
class
7
6
5
4
3
2
1
0
Low
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