Date: Thu, 14 Apr 2011 18:07:31 +0800 From: Adrian Chadd <adrian@freebsd.org> To: Peter Lai <cowbert@gmail.com> Cc: freebsd-wireless@freebsd.org Subject: Re: uplink bandwidth < 1/3 downlink bandwidth? Message-ID: <BANLkTinmhuOLqreu_M5XoD4ysceuQdMfrg@mail.gmail.com> In-Reply-To: <BANLkTikYUL4VP5SgAimi-kMc8sUU9yrL6Q@mail.gmail.com> References: <BANLkTikYUL4VP5SgAimi-kMc8sUU9yrL6Q@mail.gmail.com>
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In my home testing environment w/ 11g, and the AR5212 (but with different radio PHYs), I get the full ~ 25-28mbit TCP you'd expect with 11g, in both directions. The first thing I'd check is the results from the TX rate control module. Try "sysctl dev.ath.0.sample_stats=1" as root and check dmesg. Paste that here. That's going to be a good start. Poor TX performance can be for a variety of reasons. Let's see if we can figure it out. I'd also suggest they do this: * add the diagnostic options to the kernel and rebuild options IEEE80211_DEBUG options ATH_DEBUG options ATH_DIAGAPI options AH_DEBUG options AH_DEBUG_ALQ options ALQ * once this is done, compile/install the tools in /usr/src/tools/tools/ath/, which include athstats which is a very useful tool for debugging this kind of thing. * then compile/install /usr/src/tools/tools/net80211/wlanstats/ , it's similarly useful. (I don't have any Aruba hardware, nor do I have access to any, so I can't duplicate your environment.) adrian On 14 April 2011 17:35, Peter Lai <cowbert@gmail.com> wrote: > This is probably more of a layer1/2/management issue, but someone in > IRC told me to ask the mailinglist about it so here it goes: > > On a client running <Atheros 5212> AR2413 hardware, the uplink > bandwith appears to be very bad compared to the downlink. The downlink > I can get almost theoretical-real speed, 19Mbps/1.9Mib/s from an Aruba > centralized wifi net with WPA2, but uplink to the same AP runs at > barely 3Mbps/300Kib/s. I have a passive 9dbi duck antenna connected to > my pci card and I get s/n of 82/96 according to ifconfig wlan0 list > scan and I have set the transmitter to txpower 30 and ifconfig reports > OFDM capable at 54Mbps. Again, I can pull downlink pretty fast, and > even when I'm pulling this traffic I am pretty lag free (simultaneous > ping from the client to the aggregation router only increases by 50ms > at most), but when I upload my ping goes through the roof (up to > 3000ms) and it looks like my uplink bandwidth is overutilized. The > speeds are measured by dd at the client. Any 802.11 gurus know what > might be up with this? I'm pretty sure it's not FreeBSD specific but > maybe I can still be pointed in a direction (maybe it's a traffic > shaping policy on the AP or something). > _______________________________________________ > freebsd-wireless@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-wireless > To unsubscribe, send any mail to "freebsd-wireless-unsubscribe@freebsd.org > " >
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