Re: [WIRELESS-LAN] Spectrum Analyzer for interference detection

[David Morton]

I agree with the cognio and also recommend the yellowjacket from Berkley Veritronics (http://www.bvsystems.com/Products/WLAN/Yellowjacket/yellowjacket.htm). However you may be able to find the problem with less expensive means. As Dwight pointed out often the cause of such interference is something like a microwave or maybe a cordless phone or camera. The latter two tend to be frequency hopping and often result in decreased throughput rather than killing connections.  Is there a pattern to the drops? After the drops are the users able to get right back on?  Another possibility is that someone is actively disassociating the users from the AP. There are a number of tools that can do this. A packet sniffer and debugs on the AP may help you understand what is happening. David David Morton Director, ITI Security Solutions University of Washington [EMAIL PROTECTED] tel 206.221.7814 On Apr 4, 2006, at 1:24 PM, Emerson Parker wrote: Cognio is the way to go.   http://www.cognio.com/     I've used this several times and large installations at it will save your butt.  Cameras and wireless phones will sweep across the entire b/g spectrum and kill everything.  The software costs about 3k and vary intuitive to use.  That's a lot better than paying someone to come out.   -Emerson From: Robinson, Ronald [mailto:[EMAIL PROTECTED]] Sent: Tuesday, April 04, 2006 3:58 PM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: [WIRELESS-LAN] Spectrum Analyzer for interference detection Greetings listers, We have a suspected interference problem in a particular classroom that causes all the wireless connections to drop at the same time.  There are two APs in the classroom, and only one other AP in the building (that can be seen with NetStumbler), all are on non-overlapping channels.  It only appears to affect one particular class, but that class has 23 students all trying to use the wireless simultaneously.  I have replaced the single Cisco 350 access point with two 1200 series and have the same reported symptom.  I am beginning to suspect a wireless card in one of these students laptops as a possible source of the problem, hence my request...   Any advice on the best tools or procedures for determining if there is actually an interference problem in an 802.11B/G environment? Would a Spectrum Analyzer be of any use in tracking this down? Anyone have experience with any software based Spectrum Analyzers? Thanks ------------------------------------------------------ Ron Robinson, Network Architect, Bradley University 1501 West Bradley Ave.  |       E-Mail: [EMAIL PROTECTED] Morgan Hall Room 205F   |       Phone:  (309) 677-3350 Peoria, Illinois 61625  |       FAX:    (309) 677-3460 ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.