From: Kalle Valo <kvalo@qca.qualcomm.com>
To: Dave Taht <dave.taht@gmail.com>
Cc: <linux-wireless@vger.kernel.org>
Subject: Re: [PATCH] ath6kl: pass only unicast frames for aggregation
Date: Tue, 20 Sep 2011 11:49:55 +0300 [thread overview]
Message-ID: <4E7853B3.1080100@qca.qualcomm.com> (raw)
In-Reply-To: <CAA93jw7LnsJ-2+Js33M5JVu+Eo1920YyOiejizB9XBA04_qG_g@mail.gmail.com>
On 09/19/2011 10:40 PM, Dave Taht wrote:
> On Mon, Sep 19, 2011 at 11:38 AM, Kalle Valo <kvalo@qca.qualcomm.com> wrote:
>> When pinging form ar6003 to the AP RTT was high even when power save was
>> disabled:
>>
>> 100 packets transmitted, 97 received, 3% packet loss, time 99125ms
>> rtt min/avg/max/mdev = 1.875/46.733/795.506/139.181 ms
>>
>> After some investigation one reason for this was that received
>> multicast traffic confused the aggrecation logic and caused 400 ms
>> timeouts when receiving multicast frames from AP.
>>
>> A simple way to fix is to pass only unicast frames for aggregation. This
>> improves RTT:
>>
>> 100 packets transmitted, 99 received, 1% packet loss, time 99144ms
>> rtt min/avg/max/mdev = 2.083/13.084/403.390/56.794 ms
>
> I note that while the improvement above is enormous, a 403ms RTT for
> a packet is the rough equivalent of a detour around all of planet Earth...
> between your couch and the AP.
That's because firmware doesn't disable 802.11 power save when I ping
with one second interval. Apparently it needs two frames within ~200 ms
to disable power save.
> Can outliers of this sort be improved?
Definitely. I just want to fix serious bugs first, like the one above.
> At what point are packets dropped?
I'm guessing that the power save has issues and drops packets
occasionally. I haven't investigated it yet.
Kalle
next prev parent reply other threads:[~2011-09-20 8:50 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-19 18:38 [PATCH] ath6kl: pass only unicast frames for aggregation Kalle Valo
2011-09-19 19:40 ` Dave Taht
2011-09-20 8:49 ` Kalle Valo [this message]
2011-09-23 7:45 ` Kalle Valo
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