Testing speed over QoS

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Jul 9th, 2007
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I have a QoS enabled serial link which is divided into Platinum(8K) Gold(32K) & Silver(24K). I would like to know if there is an app or whether cisco has some facility on their routers to test the different classes for an upload and download from the LAN side to check the speed of large files being transfered over the QoS serial link?

To my knowledge the Silver class is configured for all non important traffic. Is it correct that this means that if I do an ftp from the LAN over the QoS I will only get the speed used over the silver class?



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a.cruea1980 Mon, 07/09/2007 - 06:47
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That depends on what type of QoS you are using. Some QoS will set aside a certain amount of bandwidth and never let other applications touch it (LLQ) while others (CBWFQ) will only use the bandwidth if the class that needs it is available AND there's congestion.

So, if you have LLQ set up (there's another one that sets aside bandwidth, but I can't think of what it is), then yes, all your non-important traffic will get 24K of bandwidth. If you have CBWFQ set up, then no, all your non-important traffic will get what's available and not used by the other classes (which, in this case, if the non-important were the only thing on the link, it would get 64K).

I might have the terms wrong, but it really depends what QoS you're running as to whether the bandwidth is permanently set aside or only "on demand".

vinay_verma80 Tue, 07/10/2007 - 04:50
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hi can we have the qos config , so it will be more clear to us

any how if u have used prority command than it will set aside the b.w for that class , but if u used bandwidth command than qos will be only implemented when the congestion on the harware queue and for the class

if u have no data to trafer with in the class that is using bandwidth command that B.W will redistrbuted in ration to other class (except LLQ ie prority command)


a.cruea1980 Tue, 07/10/2007 - 07:54
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I forgot to add, you can use the command "sh policy-map (int, vlan, whatever)" and it will show you the policy-maps implemented, bandwidth set aside, and how many bytes have passed through that policy. It'll also show you the past 5 minutes of bandwidth used from that policy.


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