[ath9k-devel] Performance degradation when monitor mode interface is created

[ath9k-devel] Performance degradation when monitor mode interface is created

[Ali Abedi]

Hello,

In our experiments, we use iperf to saturate the wireless link. When we 
create the monitor mode interface on the "sender" client the throughput 
drops to 25Mbps from 29Mbps. The throughout is not affected if the 
monitor mode interface is created on the receiver client through. we 
have tried various versions of ATH9K but we observed the same behavior, 
Why the monitor mode interface on the sender client affects the 
throughput? Is this a bug? We are almost sure that this is not a 
performance limitation of our clients.

Thank you,
Ali Abedi

[ath9k-devel] Performance degradation when monitor mode interface is created

[abhinav narain]

monitor interface is a virtual interface. So, two interfaces are taking the
same physical resource and there is a context switch while going back and
forth !
This will decrease the throughput as the actual interface is getting less
time to sense the channel.
Thats what I think !
-
Abhinav Narain

On Tue, Sep 4, 2012 at 3:28 AM, Ali Abedi <a2abedi@uwaterloo.ca> wrote:

> Hello,
>
> In our experiments, we use iperf to saturate the wireless link. When we
> create the monitor mode interface on the "sender" client the throughput
> drops to 25Mbps from 29Mbps. The throughout is not affected if the
> monitor mode interface is created on the receiver client through. we
> have tried various versions of ATH9K but we observed the same behavior,
> Why the monitor mode interface on the sender client affects the
> throughput? Is this a bug? We are almost sure that this is not a
> performance limitation of our clients.
>
> Thank you,
> Ali Abedi
>
> _______________________________________________
> ath9k-devel mailing list
> ath9k-devel at lists.ath9k.org
> https://lists.ath9k.org/mailman/listinfo/ath9k-devel
>
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[ath9k-devel] Performance degradation when monitor mode interface is created

[Ali Abedi]

So, why the monitor interface has no effect on the receiver client? What 
you mentioned should be true on the receiving side as well.

Thanks,
Ali

On 9/4/2012 9:21 AM, abhinav narain wrote:
> monitor interface is a virtual interface. So, two interfaces are 
> taking the same physical resource and there is a context switch while 
> going back and forth !
> This will decrease the throughput as the actual interface is getting 
> less time to sense the channel.
> Thats what I think !
> -
> Abhinav Narain
>
> On Tue, Sep 4, 2012 at 3:28 AM, Ali Abedi <a2abedi@uwaterloo.ca 
> <mailto:a2abedi@uwaterloo.ca>> wrote:
>
>     Hello,
>
>     In our experiments, we use iperf to saturate the wireless link.
>     When we
>     create the monitor mode interface on the "sender" client the
>     throughput
>     drops to 25Mbps from 29Mbps. The throughout is not affected if the
>     monitor mode interface is created on the receiver client through. we
>     have tried various versions of ATH9K but we observed the same
>     behavior,
>     Why the monitor mode interface on the sender client affects the
>     throughput? Is this a bug? We are almost sure that this is not a
>     performance limitation of our clients.
>
>     Thank you,
>     Ali Abedi
>
>     _______________________________________________
>     ath9k-devel mailing list
>     ath9k-devel at lists.ath9k.org <mailto:ath9k-devel@lists.ath9k.org>
>     https://lists.ath9k.org/mailman/listinfo/ath9k-devel
>
>

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