Excesive RTT if cell flooded with AP to STA traffic + management frames in f/w&driver queues
Laurentiu-Sorin.Paun at imag.fr
Mon Jul 5 11:31:15 EDT 2004
The large RTT values was (evidently) because of the kernel queue size of
100. Smaller values give smaller RTTs.
Also, what I am investigating is the lost of management frames (actually
Auth/Ass) in such lareg traffic situations. I understand that the
driver actually does not prioritize this management frames
My questions are:
Which management frames go in the driver and which ones rest in the f/w
? I would say that Auth/Ass only are going to the driver and Probe
Req/Resp and Beacons are analyzed by the f/w ?
Furhermore, I see that the driver has a queue which length is set by
PRISM2_TXFID_LEN. What queue are in the f/w, of what size and does it
prioritize the management frames?
Sorin PAUN wrote:
> Hi all,
> I'm looking at packet loss in condition of large traffic in the cell.
> I've found this interesting fact about the RTTs in the cell in some
> AP, STA1 and STA2 associated.
> Cell is flooded with UDP traffic, 1500B packet size, from AP to STA1.
> STA2 pings the AP :
> 100 packets transmitted, 99 received, 1% packet loss, time 99966ms
> rtt min/avg/max/mdev = 267.894/280.973/324.914/7.935 ms
> Whenever, when the cell is flooded with traffic from STA1 to AP, the RTT
> get normal values:
> 100 packets transmitted, 100 received, +2 duplicates, 0% packet loss,
> time 99990ms
> rtt min/avg/max/mdev = 2.949/8.593/31.640/5.129 ms
> What you think about this 300ms RTT?
> Thank youu
> I'm using hostap 0.2.0 with LinkSys WPC11 cards.
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