Clarification on QOS

Unanswered Question

I am currently self studying for QOS 642-642 exam. Since the book that I use didn't state this clearly, I need clarification regarding this matter.

When I use CBWFQ with either bandwith or priority command, will the layer 2 header be included in the calculation?

2nd, since the max-reserve-bandwith always defaults to 75%, will the class-default always get at least a minimum of 25% bandwith of the link (assuming that I didn't change the default setting)? Thanks.

I have this problem too.
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Brandon Buffin Fri, 01/04/2008 - 06:14

When using the bandwidth or priority commands, every bit passing through the interface is included in the calculation. This would include headers.

The bandwidth command sets a minimum amount of bandwidth for a class, but not a maximum. The priority command sets a minimum and maximum. So, at a given point in time, a class using the bandwidth command could be using more than 75% of the link. You just cannot reserve more than 75% of the link without changing the max-reserve-bandwidth. When extra bandwidth is available above what is reserved, it can be used by class class-default. If class-default does not need the bandwidth, it is divided among the other configured classes proportional to their configured rates.

Take a look at the following link.

Hope this helps. If so, please rate the post.



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