Re: [Madwifi-devel] disable cca but low pps at the receiver

[Vishal S. <vis...@gm...>]

what value are you setting for disable_cca??

vishal

On Sat, Jun 26, 2010 at 10:23 PM, zbdou <dz...@fo...> wrote:

>  I tried, but no improvements.
>
> I changed the channel to 3, which has less external interference.
> With cca enabled, the maximum throughput is 4500pps (54Mbps, 1000-byte
> broadcast frames).
> but after disable cca at the sender,
> if we set the sending interval of pktgen to tx 4500pps,
> the receiver could only get throughput of 400pps, so strange!
>
> I think there is something wrong with the patch.
>
>
>
>
>
>
> try increasing the acktimeout using
>
> sysctl -w dev.wifi0.acktimeout=30
>
> play around with couple of values and see what happens. from what i have
> observed value of around 25 us works .. with slightly higher value, the cca
> is not disabled :) (which i find strange)
>
> On Sat, Jun 26, 2010 at 9:49 PM, dead cow <dz...@fo...> wrote:
>
>> Hi,  vishal,
>>
>>        I send boradcast frames using pktgen.
>>    The ubiquity XR2 cards are used for this test.
>>
>>
>> zbdou.
>>
>>
>>
>>
>> Have you disabled the ack also or ack is enabled?? and what hardware are
>> you using??
>>
>> for ar5212 based ubiquiti and mikrotik cards what i observed is if i do
>> large file transfer of 20-30 mb using scp, then the transfer stall midway.
>> so am doubtful if the patch works accurately.
>>
>> vishal
>>
>>
>> On Sat, Jun 26, 2010 at 9:34 PM, dead cow <dz...@fo...> wrote:
>>
>> Hi, all
>> I have disabled cca/ csma,ca based on:
>> https://systems.cs.colorado.edu/projects/carp/browser/trunk/patches/noCCA.patch
>> It really works.
>> But the problom is
>> when the sender sends at the full speed at 802.11g, fixed rate 54Mbps,
>> 1000-byte frame, (around 5500 packet per frame),
>> the receiver could receive almost no frames.
>>
>> This situation is substantially mitigated when the sender transmits at a
>> lower speed (e.g. 2600pps),
>> at the receiver, we got 2300pps.
>>
>> Does anyone know the reason about this strange problem?
>>
>> Thanks!
>>
>>
>> 2010-06-26
>>
>>
>>
>> dead cow
>>
>>
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>