802.11x diagnostics

We have 60-acre wireless network with about 225 a/b/g access points.
They're currently running at 2.4Ghz b/g. We have good covereage in all
areas, but we have a few spots that seem to go dead once in a while.

I'm looking primarly for a diagnostic tool that can troubleshoot a broad
range of wireless problems. Something that can be used for a site survey
would be a plus.

I'm looking at the AirMagent Laptop Analyzer. Are there comparable tools
available that anyone could recommend?

TIA!

Spam Decoy wrote:
> We have 60-acre wireless network with about 225 a/b/g access points.
> They're currently running at 2.4Ghz b/g. We have good covereage in all
> areas, but we have a few spots that seem to go dead once in a while.
>
> I'm looking primarly for a diagnostic tool that can troubleshoot a
> broad range of wireless problems. Something that can be used for a
> site survey would be a plus.
>
> I'm looking at the AirMagent Laptop Analyzer. Are there comparable
> tools available that anyone could recommend?
>
> TIA!

I have an HP iPAQ 4551 (built in wireless and Bluetooth), and use the
PocketWinc software from Cirond (www.cirond.com) Free evaluation for 30
days, $30 for purchase. While big time analyzers are nice (but bulky etc),
having the software on a handheld makes walking the site and seeing what is
at each location, really handy. (gives the usual node name/signal
level/open-locked status/channel/MAC address etc).
Before I got the handheld, I used the regular WinC software on a laptop to
walk around, but the handheld is much lighter/and fits in my pocket.

It can do so many neat things...and running it on the handheld is really
nice. We give it to the assistant guy and have him walk around.. And to
check out new sites, we do a walkaround to make sure there is no conflict
from other systems on the channels we want to use, or after install to check
for dead spots.

No, I don't work for Cirond. Just been using their products, and am
extremely satisfied with em.

(ps, they are actually a security firm, so don't be put off by their
website)

I've been testing Ekahau (www.ekahau.com) and Visiwave
(www.visiave.com), but both are clearly out of my
price range.

Any other suggestiong out there?


"Peter Pan" <(E-Mail Removed)> wrote in
news:(E-Mail Removed):

> www.cirond.com

On Fri, 28 Jan 2005 15:06:13 -0600, Spam Decoy
<(E-Mail Removed)> wrote:

>We have 60-acre wireless network with about 225 a/b/g access points.
>They're currently running at 2.4Ghz b/g. We have good covereage in all
>areas, but we have a few spots that seem to go dead once in a while.
>
>I'm looking primarly for a diagnostic tool that can troubleshoot a broad
>range of wireless problems. Something that can be used for a site survey
>would be a plus.
>
>I'm looking at the AirMagent Laptop Analyzer. Are there comparable tools
>available that anyone could recommend?

Do your access points support SNMP? There's quite a bit that can be
extracted from the Layer 2 error reports via SNMP. For
troubleshooting, the most important item is a history of what's
considered normal. That means SNMP based data loggers, graphs (MRTG
or RRDTool), MySQL data dumpsters, and possibly some alarms (traps).
Once you have a historical graph of traffic, number of connections,
error rate, resends, retries, etc, you can determine if something has
changed.

Laptop and PDA analyzers are nifty. They will show lots of 802.11b/g
related errors. They won't show one solitary error originating from
no-802.11 devices using 2.4GHz. You can't see a cordless phone,
microwave oven, plasma lamp, frequency hopper, military, or other
source of interference. For those, I use a spectrum analyzer and the
most directional antenna that's appropriate for the occasion (i.e. I
don't wanna carry a 24dBi dish around). The antenna is the most
important part as it's used for direction finding. It also increases
the signal strength to the spectrum analyzer enough to compensate for
the lack of spread spectrum processing gain, which makes DSSS
difficult to see on a spectrum analyzer.

On my wish list is an Anritsu spectrum analyzer:

http://www.us.anritsu.com/products/A...cat3=46&cat4=0
for only $6,000. For 802.11a:

http://www.us.anritsu.com/products/A...cat3=46&cat4=0
for only $12,400. Sigh. Some day... Meanwhile, I'm using a home
made SA fabricated around a junks scope, CATV tuner front end, and
MMDS downconverter. No photos. It's a horrible mess.

If the bulk of your problems revolve around 802.11 (i.e. hackers,
co-channel users, misconfigured clients, spoofed access points, too
many DHCP servers, rogue access points, etc), then by all means,
invest in a laptop or PDA discovery tool and analyzer. I'm partial to
the free bootable Linux based Wireless diagnostic cdroms.
http://remote-exploit.org/?page=auditor
http://www.knoppix-std.org
However, if you are fighting interference from unknown non-802.11
sources, methinks a spectrum analyzer makes more sense.

For coverage issues, a PDA or laptop running Netstumbler is usually
sufficient. For site surveys, I use a telescoping fiberglass pole
with a 14dBi panel on top, 25ft of LMR-400, and whatever card is
plugged into the laptop this week. I should put the radio on top of
the pole, but have never bothered.


--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 AE6KS 831-336-2558