Hi,

I have a gentoo system and the latest Ath5k drivers from compat-wireless. I
downloaded them about a week back. I understand that the tarball is updated
daily.

I have three Ubiquiti SRC cards (AR5212). I have configured one of them as
an AP in 802.11a mode using channel 149. The other two are stations
connected to the AP. I fixed the rate to 6Mbps.

I have an iperf server running on the AP which accepts UDP traffic. One of
the stations sends UDP packets at a rate of 6Mbps to the AP. Because there
are no surrounding APs in 802.11a mode, the band is very quiet. However, I
am surprised that I get 2.6% packet loss when I run the above mentioned
experiment. The distance of both stations is no more than 10 meters from the
AP. Also, the txpower for both STAs is 30dbm.

One STA sends UDP packets to the AP at 6Mbps for 30 seconds and the report
that iperf generates is as follows:

[ ID] Interval           Transfer         Bandwidth         Jitter
Lost/Total Datagrams
[  3]  0.0-30.1 sec  18.3 MBytes  5.11 Mbits/sec  0.301 ms  352/13434 (2.6%)

Considering that there is no activity on this channel except the beacons of
AP and probe requests/responses from the other STA, how can 352 packets get
lost?

To make things worse, I tried the above experiment with minimal bandwidth.
Very oddly, the results are as follows:

[ ID] Interval           Transfer         Bandwidth        Jitter
Lost/Total Datagrams
[  3]  0.0-31.0 sec  44.5 KBytes  11.8 Kbits/sec  0.060 ms    1/   32 (3.1%)

Why would even a packet get lost at this very slow data rate? I have
repeated the above several times, and it always results in about the same
numbers.

Earlier, I had also noticed that if I ping one STA from the other STA, about
every 10 seconds, the ping response time jumps from 0.8 milliseconds to 25
milliseconds.

I would be really grateful if I can get some feedback fro myou guys on this
so that we can fix whatever is messing things up here.

Thanks,
-Qasim
_______________________________________________
ath5k-devel mailing list
ath5k-devel@lists.ath5k.org
https://lists.ath5k.org/mailman/listinfo/ath5k-devel

Reply via email to