[TriLUG] Wifi performance

[Rick DeNatale]

On 1/9/06, Joseph Mack NA3T <jmack at wm7d.net> wrote:
> On Mon, 9 Jan 2006, Greg Brown wrote:
>
> > Yes, try something other then channel three, or download
> > something like netstumbler and search for the least
> > congested channel (1, 6, or 11).  Try not to use "between"
> > channels as they can become quite noisy with chatter from
> > other APs.
>
> agree - look with netstumbler.

Netstumbler???? -- That's some windoze thing ain't it?  Only linux on
this laptop.  I've run iwlist scan from time to time, most times I
only see my own AP, although at other times I see a couple of others
running on channel 6. I don't know why these other accesss points are
coming or going or if they only show up for awhile after I've changed
something on the ap and my card hasn't completely "locked on" to it. 
Note that I'm using WPA with wpa_supplicant

Right after changed my WAP to channel 1, I saw:
rick at bill:~$ iwlist ath0 scan
ath0      Scan completed :
          Cell 01 - Address: 00:0F:66:42:A0:C6
                    ESSID:"DenHavenII"
                    Mode:Master
                    Frequency:2.412 GHz (Channel 1)
                    Quality=43/94  Signal level=-52 dBm  Noise level=-95 dBm
                    Encryption key:on
                    Bit Rate:1 Mb/s
                    ... Clipped other bit rates for the post
                    Bit Rate:54 Mb/s
                    Extra:bcn_int=100
                    Extra:wpa_ie=dd180050f20101... (I've shortened this)

          Cell 02 - Address: 00:0F:66:49:39:5E
                    ESSID:"linksys"
                    Mode:Master
                    Frequency:2.437 GHz (Channel 6)
                    Quality=5/94  Signal level=-90 dBm  Noise level=-95 dBm
                    Encryption key:off
                    Bit Rate:1 Mb/s
                    ...
                    Extra:bcn_int=100
          Cell 03 - Address: 00:90:4B:12:C6:ED
                    ESSID:"Motorola"
                    Mode:Master
                    Frequency:2.437 GHz (Channel 6)
                    Quality=7/94  Signal level=-88 dBm  Noise level=-95 dBm
                    Encryption key:off
                    Bit Rate:1 Mb/s
                    ...
                    Extra:bcn_int=100

I switched my AP to channel 11, and the other two were visible for
what seems like 10s of minutes but now are gone again.

>
> If it's interference, can you take your setup to the middle
> of a field (you'll need an inverter for the wap) and see if
> that fixes it.
>

Not really practical, this wap is part of an infrastructure lan, I'd
need a looonng cat-5 cable to put it in a field and hook up to my
network.


I'm currently writing a ruby script which will sample the stats from
iwconfig and ifconfig so that I can see how the errors change over
time and with changes to the configuration of the WAP.

--
Rick DeNatale

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