Null function when scanning.

Jouni Malinen jkmaline at cc.hut.fi
Wed Feb 9 23:52:14 EST 2005


On Wed, Feb 09, 2005 at 11:39:21PM -0500, Andrea G. Forte wrote:
> >Normally, these frames are used to notify the current AP that the client
> >is moving to power save mode and the AP should buffer frames. This can
> >be used to avoid dropping packets when the station is scanning on
> >another channel.
> > 
> >
> Since I am not using power save mode I believe the second point you 
> mentioned is what it's happening for me.

Please note that I did not say this would require power save mode being
enabled..

> Does this mean that the firmware takes care of this? Is there a way in 
> the driver to disable this "forced" buffering?

Yes, station mode scanning is in firmware and no, I don't think there is
configuration option for this part in the driver.

> This behaviour does not help much for real time applications such as 
> VoIP since these frames introduce a delay in the handoff process.

Not necessarily.. Background scans are supposed to happen before the
station needs to roam and at this point, it is useful to stop the
current AP from sending data frames. This may not be that useful if the
connection is already lost, though, but in that case it is already too
late to avoid VoIP issues, if a new scan is required.

-- 
Jouni Malinen                                            PGP id EFC895FA



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