Le Sat, 26 Jul 2008 16:10:59 -0500, Larry Finger <Larry.Finger@xxxxxxxxxxxx> a écrit : > Cédric Auger wrote: > > Le Sat, 26 Jul 2008 10:54:41 -0500, > > Larry Finger <Larry.Finger@xxxxxxxxxxxx> a écrit : > > > >> Felix Fietkau wrote: > >>> I don't know if it helps with debugging this issue, but I've seen > >>> the same on a laptop from a friend of mine (same card). > >>> > >>> After some searching I found that setting the AP to g-only mode > >>> instead of b+g mixed made it work at decent speeds. Another > >>> symptom of this slowdown is that there is typically an > >>> unnaturally high number of retransmissions on the air, which eats > >>> up a lot of airtime. > >>> > >>> I've spent some time looking through the code to find the reason > >>> for this but couldn't find anything yet (maybe somebody from Intel > >>> could help). > >> Just for comparison, my BCM4312 running b43 from the latest > >> wireless-testing gets the following tcpperf throughput: > >> > >> AP Mode TX RX > >> > >> Mixed b/g 19.8 MB/s 23.0 MB/s > >> g-only 20.5 MB/s 23.1 MB/s > >> > >> For these tests, the connecting end was wired to the router. The > >> difference in TX speeds was about what I expected - the small > >> difference in RX speeds was not. In any case, if you see a large > >> difference with iwl3945, that would be useful information. > >> > >> You can obtain tcpperf from > >> http://wand.cs.waikato.ac.nz/~stj2/nsc/software.html > > > > hello > > thanks for your answers. > > i tried to set my ap to g-only, but i cannot :-( the wifi box is > > given by my provider and it seems cannot be changed... > > so i tried tcpperf, this is the result : > > > > cedric:/home/grisbi/tcpperf-1.754# ./tcpperf -c 192.168.0.4 -t 30 > > Duration: 30 9482usec > > Bytes sent: 5481472 (5353 kB 5 MB 0 GB) > > Bandwidth: 1461264 b/s (1461.26 kb/s 1.46 Mb/s) > > Close duration: 0s 22usec > > > > then i tried to download an image of ubuntu and i had about 900kb/s, > > so very good and i don't understand... then i tried to send a big > > file with scp to the other computer, as user and as root, it begins > > at 2,2MB/s and decrease untill 150kb/s and stays between 130-200kb/s > > i did again a tcpperf with -t 300 to check if it's not with the > > time, but i have 1,30MB/s, seems correct. > > > > second test : > > i stop the wifi and plug a cable. the second computer is still in > > wifi. tcpperf gives me 17Mb/s and the same file with scp is sent > > with about 2,2MB/s... > > so now i really don't understand, from internet, loading work untill > > 900kb/s (ok for me), but beween 2 computers on my network i have max > > 200kb/s... > > hopes this can be usefull > > It looks as if your receive rate is a lot higher than the transmit > rate. You can check that by using the computer with the iwl3945 as > the server and initiate tcpperf from the other end. hi i didn't think about that... i did the test and i have a bandwidth of 7,55Mb/s... more than for the other test... so i did a transfer by scp from the other computer to my computer, begin to 2,2Mb/s and decrease to 930kb/s, which is good for me. so if i resume : my computer 1 to computer 2 : 100-200kb/s computer 2 to computer 1 : 950kb/s internet to computer 1 : 950kb/s then download seems correct, but upload seems bad. but if we look the results of tcpperf : computer 1 to computer 2 : 1,5Mb/s computer 2 to computer 1 : 7,5Mb/s perhaps 1,5Mb/s for upload is not good as i thought ? thanks cedric -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
