Bad host-vased AP performace -- and qouple of questions about FreeBSD WiFi stack tuning

Lev Serebryakov lev at
Tue Aug 9 09:27:52 UTC 2011

Hello, Bernhard.
You wrote 9 августа 2011 г., 10:29:18:

>> (1) Hopping signal strength and total terrible WiFi network
>>     performance -- is it broken hardware or something strange in
>>     FreeBSD code?
> Either the hardware really has some issues or the signal strength is
> just too high? I've seen that.. can you try setting a lower txpower
> for a test?
  I'll try to reduce txpower, thanks.

>> (2) Why card announce only 18Mbit, but not more?
> Seems like you're looking at the "basic rates", if you examine the
> beacon you should find another IE which contains all rates.
  Oh, yep, Tag number = 50. It is strange enough, that different WiFi
 analyzers shows only 18M for my network and 54M for others in such
 case. It seems, here is another (more standard? more widely used by
 hardware SOHO soapboxes?) way to specify additional rates.

> at it might even in half-dbm. The iwn(4) cards for example have a
> txpowerlimit of 15 dBm which is 30 in half-dBm.
  How these dBm can be converted to mW? :) If it is "dBm" with 1W used
 as base (30dBm), it means, that 15 dBm is only 32mW, that is 1/3 of
 "standard" 100mW WiFi power.

// Black Lion AKA Lev Serebryakov <lev at>

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