CBWFQ - query

Unanswered Question
Oct 6th, 2008


Can someone advice if the following will work?

access-list 101 permit tcp eq 888

class-map match-all test

match access-group 101

class-map match-any voice-test

match ip dscp ef

policy-map test-policy

class voice-test


class test

bandwidth 3750000

queue-limit 64

class class-default

bandwidth 3750000

queue-limit 64

int te1/1

service-policy output test-policy

With CBWFQ, do you still have to configure the weights, threshold for all queues for the interface?

For example

int te1/1

wrr-queue queue-bandwidth 10 20 10 10 10 20 20

wrr-queue random-detect 1




I have this problem too.
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satish_zanjurne Mon, 10/06/2008 - 23:52

1.The above policy-map should be good for routers

2.Policy map does not give option of priority instead policy map actions on Catalyst 3550 can include trusting the CoS, DSCP, or IP precedence values in the traffic class; setting a specific CoS, DSCP, or IP precedence value in the traffic class; and specifying the traffic bandwidth limitations for each matched traffic class (policer) and the action to take (marking) when the traffic is out of profile.

3.WRR is a mechanism that is used in output scheduling on the 3550. WRR works between three or four queues (if there is no strict priority queue). The queues that are used in the WRR are emptied in a round-robin fashion, and you can configure the weight for each queue.

4.Gigabit capable ports has egress expedite queue facility using "priority-queue out" command instead of "priority"

So on typical router WRR or SRR is not available

Catalyst 3550 supports WRR

Catalyst 3760 supports SRR

Catalyst 3750 supports SRR

Catalyst 6500 supprts WRR & SRR

For more information WRR on Catalyst 3550 refer below link


HTH..rate if helpful..

pokwan Tue, 10/07/2008 - 14:36


Thanks for the reply. We have Cat 6500 switches. We have a tengigabit link joining two locations. The port is capable of 1p7q8t. In our review, we were adviced to use CBWFQ for QoS. The document on CISCO website on CBWFQ did not have the 6500 in the supported platform.

Are you saying that CBWFQ is for routers and not switches? For the 6500, what would you recommend and do you have any examples?




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