could someone exp the below.. thanks

Unanswered Question
Feb 6th, 2009
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class-map match-all xxx-xxx

class-map match-all xxx-xxx

description "99=xxx, xx"

match ip dscp xxx

class-map match-all xxx-xxx

description "100=xxx=xxx,


match ip dscp xxx

policy-map ???

class xxx-xxx

bandwidth percent 60

queue-limit 128

class xxx-xxx

bandwidth percent 8

queue-limit 128

Then the service policy is placed on an interface

ppp multilink group xx

ppp multilink endpoint ip

ppp multilink fragment delay 2

"service-policy output AAAA"

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b.julin Thu, 02/12/2009 - 18:14
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It's dropping packets (when congested) based on IP DSCP header bits. Looks fairly standard.

Giuseppe Larosa Thu, 02/12/2009 - 22:26
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Hello Beulah,

this is an example of a scheduler of type CBWFQ.

Two traffic classes are defined based on the value of the DSCP bye in the IPv4 header.

The CBWFQ is then applied outbound a multilink bundle.

First class can use up to 60% of bandwidth under congestion

Second class can use up to 8% of bandwidth under congestion.

To be noted that CBFWQ is elastic if there are free resources bandwidth one class can go up the bandwidth settings (there is no embedded policing at the specified rate)

see for CBWFQ from 12.4 QoS config guide

Hope to help


Joseph W. Doherty Fri, 02/13/2009 - 04:40
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"First class can use up to 60% of bandwidth under congestion

Second class can use up to 8% of bandwidth under congestion. "

How this was descibed, might be a bit misleading. To clarify, if 100% of the bandwidth was defined, and all classes, each wanting 100% of the bandwidth, then each class should receive the defined percentage. If not all classes wanted all bandwidth, they can use more. For instance, if 1st was only using 50% and 2nd class wants 100%, the second class should be able to obtain 50% because the first class wasn't using all it was guaranteed.

Also in this example 100% of the bandwidth wasn't "allocated", so the two classes should, I believe, if they both wanted 100%, proportion their bandwidth 60:8, or 7.5 to 1. I.e. both should obtain more than their minimum percentages.

Lastly, there's an implicit class-default that would be applied to traffic not matching the defined classes (and for other special traffic purposes). Normally, CBWFQ won't allow you to defined more than 75% of the bandwidth explicitly.


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