Enterprise QoS Solution Reference Network Design Guide

Catalyst 3550—QoS Considerations and Design
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Table 2-2 Catalyst 3550 Auto-QoS Generated Configuration
The switch automatically assigns egress
queue usage on this interface.
The switch enables the egress expedite
queue and assigns WRR weights to queues
1, 2, and 3. (The lowest value for a WRR
queue is 1and is the recommended setting
for Q4 when it is operating as an expedite
queue.)
The switch configures the
CoS-to-egress-queue map:
CoS values 0 and 1 select queue 1.
CoS values 2 and 4 select queue 2.
CoS values 3, 6, and 7 select queue 3.
CoS value 5 selects queue 4 (expedite
queue).
Because the expedite queue (queue 4)
contains the VoIP data traffic, the queue is
serviced until empty.
On Gigabit-capable Ethernet ports only,
the switch automatically configures the
ratio of the sizes of the WRR egress
queues:
Queue 1 is 50 percent.
Queue 2 is 25 percent.
Queue 3 is 15 percent.
Queue 4 is 10 percent.
On 10/100 Ethernet ports only, the switch
automatically configures
minimum-reserve levels for the egress
queues:
Queue 1 selects the minimum-reserve
level 5.
Queue 2 selects the minimum-reserve
level 6.
Queue 3 selects the minimum-reserve
level 7.
Queue 4 selects the minimum-reserve
level 8.
Enterprise QoS Solution Reference Network Design Guide
Chapter 2 Campus QoS Design
C3550(config-if)# wrr-queue bandwidth 10 20 70 1
C3550(config-if)# no wrr-queue cos-map
C3550(config-if)# wrr-queue cos-map 1 0 1
C3550(config-if)# wrr-queue cos-map 2 2 4
C3550(config-if)# wrr-queue cos-map 3 3 6 7
C3550(config-if)# wrr-queue cos-map 4 5
C3550(config-if)# priority-queue out
C3550(config-if)# wrr-queue queue-limit 50 25 15
10
C3550(config-if)# wrr-queue min-reserve 1 5
C3550(config-if)# wrr-queue min-reserve 2 6
C3550(config-if)# wrr-queue min-reserve 3 7
C3550(config-if)# wrr-queue min-reserve 4 8
Version 3.3