[LAU] netjack and WiFi

[Bengt Gördén]

lördag 09 januari 2010 20:30:35 skrev  Michal Seta:
> Hi all,
> 
> Happy new decade!
> 
> Back on that WiFi jamming issue I wrote about a while ago.  Thank you
> all for the various suggestions.  I have spent most of my time trying
> to get somewhere with netjack as I found it the most promising, not
> only in terms of efficiency but also scripting and control.  However,
> I have hit some brick walls which are certainly due to the nature of
> WiFi networks (packet collisions and such) which make my setup very
> unstable.
> 
> First of all, in my setup, there will be one "server" computer
> collecting 5 signals from the 5 musicians and playing them for the
> audience.  Moreover, the operator (or software) will send back 5 mono
> signals to performers (one signal per performer).  The idea is that
> each performer hears only one instrument at a time.
> 
> Currently the show stopper lies in alsa_in and alsa_out components.
> Whenever I run both on my netbook (Atom 1.6G with Atheros
> Communications Inc. AR5001 Wireless Network Adapter (802.11g)) they
> consume around 70-80%CPU and they peak at around 50% each whenever
> they choke on net over/underruns.  They eventually segfault (and
> sometimes bring the jack server down with them.  This particularly
> true whenever the WiFi signal signal strength is weak (around 50-60%).

driver?
kernel version? (rt-kernel?)

Don't know about netjack but the ath5k (it is ath5k right?) driver do have 
some outstanding bugs right now. You use Karmic and it has 2.6.31, right? So 
it appears that there is several reports on problem with the driver and 
wireless signal strength. This might give you stability problems. There is 
also problems reported on wireless AP (see last link).

http://bugzilla.kernel.org/buglist.cgi?query_format=specific&order=relevance+desc&bug_status=__all__&product=&content=ath5k

And especially
http://bugzilla.kernel.org/show_bug.cgi?id=13958

And the last comment in this one
http://bugzilla.kernel.org/show_bug.cgi?id=13892


/bengan