ath: a few questions

Kris Maglione bsdaemon at comcast.net
Tue Jan 18 10:28:17 PST 2005


Sam Leffler wrote:

> Kris Maglione wrote:
>
>> Bruce M Simpson wrote:
>>
>>> On Tue, Jan 18, 2005 at 09:40:21AM -0500, Kris Maglione wrote:
>>>  
>>>
>>>> Second, according to CVS, hw.ath.outdoors was made tunable a year 
>>>> ago, but sysctl says it's readonly when I try to change it. It's 
>>>> stuck at 1, which seems to be a possible explanation for why it's 
>>>> indoor use sucks so badly compared to the windows driver, 
>>>> especially through walls.
>>>>   
>>>
>>>
>>>
>>> I'm running 5.3-STABLE as of last Wednesday and do not see this sysctl.
>>>
>>> Please give version information (uname -a) when posting this kind of 
>>> query,
>>> as it's next to impossible to give useful advice otherwise.
>>>  
>>>
>> Sorry about that. No uname -a, but it's the 5-STABLE from about a few 
>> days ago. The kernel config file is actually the (minimally modified) 
>> FreesBIE config file from a few months ago, but why is a long story.
>
>
> The setting is a read-only sysctl because once the module is loaded 
> changing it has no effect.  Set it before you kldload the module or in 
> your hints file if you want it different than the default.
>
>>
>>> You should be able to 'tcpdump -i ath0 -y ieee802_11' to verify that 
>>> you
>>> can capture 802.11 packets straight off the card.
>>>  
>>>
>> I have done that, and I have used kismet. My problem with kismet 
>> turned out to just be a wierd way that kismet reports things.
>
>
> kismet has been broken for a while.  It used to work but something 
> broke it and I've had no time to dig (it's painful to debug as it's a 
> multi-process app written in C++ and makes heavy use of STL so 
> inspecting data structures is a pain).
>
>>
>>> I haven't experienced the problems with walls you mention.
>>>  
>>>
>> I use 11a. Like I said, there is no problem with windows. I forgot to 
>> mention that windows also reports higher data rates (54Mbps when 
>> FreeBSD reports 18Mbps, but I don't trust that, really. It reports up 
>> to 108Mbps in turbo, but the AP only supports 76). Also, through a 
>> wall or two, windows reports high signal, but I can't test that in 
>> freebsd, since the driver doesn't seem to support it.
>
>
> You've provided zero useful information so I've been ignoring your 
> winging.  Regardless you are comparing apples and oranges.  The NDIS 
> driver supports several hardware features that the open source driver 
> does not.  At least one of those, XR mode, can be a significant factor 
> in the extended range performance you see.  The other critical factor 
> is that the NDIS driver has an excellent transmit rate control 
> algorithm while the onoe rate control code is little more than a 
> noop.  I've solicited better algorithms for almost 3 years but noone's 
> stepped up. I cannot do one because I am familiar with several 
> proprietary algorithms and so "tainted".

Sorry, I haven't provided any useful information, because I don't know 
what information to provide.

transmit rate is not the only issue.  NetStumbler finds 4 (2 entirely 
unprotected) APs in my neighborhood, while kismet only finds 2 (one of 
which NetStumbler doesn't). Since kismet doesn't transmit, there must be 
some other issue at play, I just don't know how to find it.

>
>>
>>>  
>>>
>>>> Last, dstumbler doesn't work. It complains, something about ioctl. 
>>>> I don't feel like booting the laptop to get the exact messate at 
>>>> the moment, but I will later.
>>>>   
>>>
>>>
>>>
>>> dstumbler is for PRISM2 cards only.
>>>  
>>>
>> thanks, I had a feeling that it was, but I had to ask.
>
>
> dstumbler should work with ath however I don't find it (or kismet) 
> especially useful.
>
>     Sam
> _______________________________________________
> freebsd-mobile at freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-mobile
> To unsubscribe, send any mail to "freebsd-mobile-unsubscribe at freebsd.org"


-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 254 bytes
Desc: OpenPGP digital signature
Url : http://lists.freebsd.org/pipermail/freebsd-mobile/attachments/20050118/f7377c42/signature.bin


More information about the freebsd-mobile mailing list