Qos Configuration For The Existing Wiring Closet - Cisco Catalyst 3550 series Software Configuration Manual

Standard QoS Configuration Examples
Figure 29-11 QoS Configuration Example Network

QoS Configuration for the Existing Wiring Closet

The existing wiring closet in
switches are running Cisco 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 3500 XL and 2900 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 ISL or 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 3500 XL, 2950, other 2900
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.
Catalyst 3550 Multilayer Switch Software Configuration Guide
29-70
Gigabit Ethernet 0/1
Existing wiring closet
Catalyst 2900 and 3500 XL
switches
End
stations
Figure 29-11
Cisco router
To Internet
Gigabit Ethernet 0/5
Catalyst 3550-12G switch
Gigabit Ethernet 0/2
Intelligent wiring closet
Catalyst 3550 switches
Trunk Trunk
link link
Gigabit
Ethernet
0/2
consists of Catalyst 3500 XL and 2900 XL switches. These
Chapter 29 Configuring QoS
Video server
172.20.10.16
Gigabit
Ethernet
0/1
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