802.11x diagnostics

I have an HP iPAQ 4551 (built in wireless and Bluetooth), and use the PocketWinc software from Cirond

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)

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:

only $6,000. For 802.11a:

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.

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.

I've been testing Ekahau

and Visiwave but both are clearly out of my price range.

Any other suggestiong out there?

"Peter Pan" wrote in news: snipped-for-privacy@individual.net: