DTIM (Power Save Mode) w/ HostAP

A compatibility issue arose from testing BSD HostAP mode with an Intel 
Centrino 11b client.  (Stay tuned at your favorite airport, net coffee 
shop, etc. on March 12th for all the marketing foo on Centrino.)  When the 
NIC in question (rumored to be a recycled Symbol MAC) has power management 
enabled (the big selling point of Centrino silicon suite), poll requests 
aren't processed correctly by the HostAP mode driver.  Thus, the STA keeps 
sending re-tries (PS-Poll) to download its "buffered" data.

* It would appear that in 4.7-STABLE the (D)TIM period is set to 0, while 
5.0-RELEASE it's 1.  Does anyone know why this changed (obviously the 
import from NetBSD's codebase, but why does it differ)?

* Has anyone else had problems with power save mode STA's and HostAP?

* Has anyone even tried it (I'm told this issue also applies to 
Lucent/Orinoco STA's with power save enabled too)? ;)

While it's possible to change the advertised DTIM period in the beacons, 
actual support doesn't seem exist within the Prism STA f/w (thus the HostAP 
mode driver can't make cookies w/o dough) - 
<http://hostap.epitest.fi/hostap/2002-07/1128.html>.  The Linux HostAP 
driver would seem to confirm this.. 
<http://hostap.epitest.fi/cgi-bin/viewcvs.cgi/hostap/ChangeLog>..

	DTIM period, i.e., number of beacon intervals between
	successive delivery traffic identification maps (DTIMs),
	used for power saving and multicast/broadcast delivery,
	default 1 (this was previously always hardcoded to 3).

	removed DTIM and Tick event handling since they were
	not used for anything (and DTIM event would require AP
	f/w anyway)

I could also be totally wrong with the above info, I'm not a good code 
parser/etc (especially frustrating is Intersil's knowledge base, which 
references chapters in the programmers manual that don't exist, grr).  I 
plan to post prism2dump and/or Airopeek dumps of this in action in the 
coming days.  My testing has been against 4.7-STABLE with f/w 1.4.9 & 1.5.6.

* All names and brands can be claimed the property of others.  Don't shoot 
the messenger.

--
Matt Peterson         another.geek.without.a.life
[email protected]       http://matt.peterson.org/
-------------------------------------------------
--
*bsd wireless list, a bawug thing <http://www.bawug.org/>
[un]subscribe: http://lists.bawug.org/mailman/listinfo/bsd-wireless/