13-26
Catalyst 2950 Desktop Switch Software Configuration Guide
78-11380-03
Chapter 13 Configuring QoS
QoS Configuration Examples
Figure 13-4 QoS Configuration Example Network
QoS Configuration for the Common Wiring Closet
The common wiring closet in Figure 13-4 consists of existing Catalyst 2900 XL and 3500 XL switches.
These switches are running IOS release 12.0(5)XP or later, which supports the QoS-based IEEE 802.1P
CoS values. QoS classifies frames by assigning priority-indexed CoS values to them and gives
preference to higher-priority traffic.
Recall that on the Catalyst 2900 and 3500 XL switches, you can classify untagged (native) Ethernet
frames at the ingress ports by setting a default CoS priority (switchport priority default
default-priority-id interface configuration command) for each port. For IEEE 802.1Q frames with tag
information, the priority value from the header frame is used. On the Catalyst 3524-PWR XL and 3548
XL switches, you can override this priority with the default value by using the switchport priority
default override interface configuration command. For Catalyst 2950 and Catalyst 2900 XL switches
and other 3500 XL models that do not have the override feature, the Catalyst 3550-12T switch at the
distribution layer can override the 802.1P CoS value by using the mls qos cos override interface
configuration command.
Cisco router
Existing wiring closet
Catalyst 2900 and 3500 XL
switches
Intelligent wiring closet
Catalyst 2950 switches
To Internet
Catalyst 3550-12G switch
Gigabit Ethernet 0/5
Gigabit Ethernet 0/2
Gigabit
Ethernet
0/2
Gigabit
Ethernet
0/1
Trunk
link
Gigabit Ethernet 0/1
Trunk
link
End
stations
Video server
172.20.10.16
65288
To Next Page
Loading...
Need help?
General
