notes: 3550 & 3560 QoS

3550
fastethernet
QOS scheduling: tx-(4q0t),tx-(1p3q0t)

gigabitethernet
QOS scheduling: tx-(4q2t),tx-(1p3q2t)

- priority at queue 4
- default port cos 0
- default port is untrusted
- default cos to tx queue mapping
0 - 1
1 - 1
2 - 2
3 - 2
4 - 3
5 - 3
6 - 4
7 - 4

- default cos-dscp map

show mls qos maps cos-dscp
Cos-dscp map:
cos: 0 1 2 3 4 5 6 7
--------------------------------
dscp: 0 8 16 24 32 40 48 56

- default wrr weights
wrr bandwidth weights:
qid-weights
1 - 25
2 - 25
3 - 25
4 - 25

weight 4 range (0-255) when set to "0" it is configured as expedite queue

3560
QoS scheduling: tx-(4q2t)
-same cos-tx queues mapping
-same cos-dscp mapping
- same queue bandwidth weights
-no vlan-based classification
- can use class based marking to set dscp



to verify queing

show mls qos interface queueing

to change cos-dscp mapping:

mls qos map cos-dscp (dscp-values)


config-set for 3550 setting cos-tx queues mapping:

Rack1SW3(config-if)#wrr-queue cos-map 1 0 1 2
Rack1SW3(config-if)#wrr-queue cos-map 2 3
Rack1SW3(config-if)#wrr-queue cos-map 3 4
Rack1SW3(config-if)#wrr-queue cos-map 4 5
Rack1SW3(config-if)#priority-queue out ---configure priority queueing

Rack1SW3#show mls qos interface queueing
FastEthernet0/1
QoS is disabled. Only one queue is used
When QoS is enabled, following settings will be applied
Egress expedite queue: dis
wrr bandwidth weights:
qid-weights
1 - 25
2 - 25
3 - 25
4 - 25
Cos-queue map:
cos-qid
0 - 1
1 - 1
2 - 1
3 - 2
4 - 3
5 - 4
6 - 4

ex:

wrr-queue bandwidth 1 2 3 4

10%- queue1
20%-queue2
30%-queue3
40%-queue4