Date: Tue, 10 Feb 2009 13:14:01 -0800 From: Joseph Lee <nugundam@gmail.com> To: Sepherosa Ziehau <sepherosa@gmail.com> Cc: freebsd-net <freebsd-net@freebsd.org>, Andrew Thompson <thompsa@freebsd.org> Subject: Re: kern/124753: net80211 discards power-save queue packets early Message-ID: <4991EE19.5020401@gmail.com> In-Reply-To: <ea7b9c170806190622u5a9501a4vab53ff1be8c9368a@mail.gmail.com> References: <200806191030.m5JAU36i027140@freefall.freebsd.org> <ea7b9c170806190622u5a9501a4vab53ff1be8c9368a@mail.gmail.com>
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I apologize for following up so late on this. I've only now have time to follow up. Sepherosa Ziehau wrote: > On Thu, Jun 19, 2008 at 6:30 PM, <remko@freebsd.org> wrote: >> Synopsis: net80211 discards power-save queue packets early >> >> Responsible-Changed-From-To: freebsd-i386->freebsd-net >> Responsible-Changed-By: remko >> Responsible-Changed-When: Thu Jun 19 10:29:47 UTC 2008 >> Responsible-Changed-Why: >> reassign to networking team. >> >> http://www.freebsd.org/cgi/query-pr.cgi?pr=124753 > > In How-To-Repeat, you said: > "Then associate a recent Windows Mobile 6.1 device to the FreeBSD box > running hostapd ..." > > In Description, you said: > "The WM6.1 device recv ps-poll's for packets every 20 seconds ..." > > AFAIK, STA sends ps-poll to AP; AP does not send ps-poll to STA. Why > did your windows STA receive ps-poll from freebsd AP? Did you capture > it by using 802.11 tap? > > And which freebsd driver were you using? I'm using the ath wifi driver. The upgrade to FreeBSD 7.1 has not changed WiFi behavior. > Your problem looks like: > - Either freebsd AP did not properly configure TIM in beacons, which > could be easily found out by using 802.11 tap. But I highly suspect > if you were using ath(4), TIM would be misconfigured. What is tap? > - Or your windows STA didn't process TIM according to 802.11 standard. Sam Leffler wrote: >The PR states the listen interval sent by the station is 3 (beacons) and the beacon >interval is 100TU. This means the AP is required to buffer unicast frames for only 300TU >which is ~300 ms. But according to the report the Windows device is polling every 20 >seconds so there's no guarantee any packets will be present (even with the net80211 code >arbitrarily using 4x the list interval specified by the sta). I find it really hard to >believe a device would poll every 20 secs so something seems wrong in what's >reported/observed. The device is in its best power-saving mode where it make take time to respond to any packets. I only have this problem with FreeBSD hostap on the switch from FreeBSD 6 -> 7. Other APs such as Netgear/Linkgear have no issues, but can be postulated they don't implement PM as FreeBSD currently does. Also, on this same FreeBSD wifi-ap, no laptops have the same issue. So, it's isolated between FreeBSD and Windows Mobile. >Given that defeating the aging logic just pushed the problem elsewhere it sounds like >there's something else wrong which (as you note) probably requires a packet capture to >understand. I'm pretty sure TIM is handled correctly in RELENG_7 but a packet capture >would help us verify that. What do I need to do get you guys a packet capture to verify the TIM? Thanks, Joseph
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