RE: [WIRELESS-LAN] Spectrum Analyzer for interference detection
One letter A ;) -Original Message- From: Lee Badman [mailto:[EMAIL PROTECTED] Sent: Thursday, April 06, 2006 4:28 PM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Spectrum Analyzer for interference detection Fred- I say "bring 'em on". It is unlicensed spectrum, and research should be as high on the priority totem as anything at a University. Then (and if) the WLAN gets creamed, take your WLAN vendor to task and make them work for their dollar to make their systems more adept at dealing with this stuff, as it's not going away. One man's opinion:) Lee Lee Badman Network Engineer CWNA, CWSP Information Technology and Services (Formerly Computing and Media Services) Syracuse University (315) 443-3003 [EMAIL PROTECTED] >>> [EMAIL PROTECTED] 4/6/2006 11:29 AM >>> Does anyone know if the Cognio product has profiles for ZigBee devices ? When I last checked with them about 6 months ago, they did not. We have a number of groups who want to use 802.15.4 devices in their research. My concern is interference in the 2.4Gig range and the overall raising of the noise floor. This has become a very crowded spectrum in our neighborhood . I am not so worried about just a few of these devices . However, I have had several research groups that each want to deploy 100+ of these in a single floor or building for their research in sensor nets. I am concerned about the cumulative effect of these on 802.11b. Fred Archibald 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/. ** 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/.
Re: [WIRELESS-LAN] Spectrum Analyzer for interference detection
Fred- I say "bring 'em on". It is unlicensed spectrum, and research should be as high on the priority totem as anything at a University. Then (and if) the WLAN gets creamed, take your WLAN vendor to task and make them work for their dollar to make their systems more adept at dealing with this stuff, as it's not going away. One man's opinion:) Lee Lee Badman Network Engineer CWNA, CWSP Information Technology and Services (Formerly Computing and Media Services) Syracuse University (315) 443-3003 [EMAIL PROTECTED] >>> [EMAIL PROTECTED] 4/6/2006 11:29 AM >>> Does anyone know if the Cognio product has profiles for ZigBee devices ? When I last checked with them about 6 months ago, they did not. We have a number of groups who want to use 802.15.4 devices in their research. My concern is interference in the 2.4Gig range and the overall raising of the noise floor. This has become a very crowded spectrum in our neighborhood . I am not so worried about just a few of these devices . However, I have had several research groups that each want to deploy 100+ of these in a single floor or building for their research in sensor nets. I am concerned about the cumulative effect of these on 802.11b. Fred Archibald 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/. ** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
Re: [WIRELESS-LAN] Spectrum Analyzer for interference detection
Does anyone know if the Cognio product has profiles for ZigBee devices ? When I last checked with them about 6 months ago, they did not. We have a number of groups who want to use 802.15.4 devices in their research. My concern is interference in the 2.4Gig range and the overall raising of the noise floor. This has become a very crowded spectrum in our neighborhood . I am not so worried about just a few of these devices . However, I have had several research groups that each want to deploy 100+ of these in a single floor or building for their research in sensor nets. I am concerned about the cumulative effect of these on 802.11b. Fred Archibald 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/.
RE: [WIRELESS-LAN] Spectrum Analyzer for interference detection
I haven't had a chance to test this in the field, only briefly in my lab, but I've read really good reviews on the Wi-Spy by Metageek. Nothing fancy, but it is real-time and is a LOT cheaper than the next most expensive device. It's only $100! http://www.thinkgeek.com/gadgets/electronic/80ce/ http://www.metageek.net/ Regards, Eric Barnett Wireless Administrator Information and Technology Services Arkansas State University 870 972 3033 http://wireless.astate.edu -Original Message- From: Howie Frisch [mailto:[EMAIL PROTECTED] Sent: Tuesday, April 04, 2006 4:28 PM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Spectrum Analyzer for interference detection Technically, this is correct, but in the environment I would suspect either a 2.4GHz frequency hopping cordless phone (look for the Panasonic's - they work well as cordless phones, are cheap, and will reliably knock off 802.11b/g connection). The microwave oven is another good source of interference. While a DOS attack is possible, it seems like a lot of trouble to go after one classroom. I would also recommend giving one 802.11a access point a try. Many will not be able to use it, but microwave ovens won't bother it much either. Howie Frisch [EMAIL PROTECTED] Michael Gregory wrote: > Or maybe a DOS attack. Not only can an attacker unauthenticate a user > but some Wireless management applications have defense mechanisms > built in to protect their networks. > > An attacker can disrupt service from the protocol level. Remember that > we talked about establishing associations to use the wireless network? > If you can build an association, then there must be a way to > disassociate. If you can authenticate, then there must be a way to > unauthenticate. Unfortunately, in the IEEE 802.11b standard, both > methods exist, and both methods do not require any authentication in > the message. That means the attacker can send out a disassociate or > unauthenticate message to an arbitrary wireless network user and > disconnect them. This is a bad design from the protocol's perspective. > > > > Robinson, Ronald wrote: > >> >> 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/. ** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
Re: [WIRELESS-LAN] Spectrum Analyzer for interference detection
Technically, this is correct, but in the environment I would suspect either a 2.4GHz frequency hopping cordless phone (look for the Panasonic's - they work well as cordless phones, are cheap, and will reliably knock off 802.11b/g connection). The microwave oven is another good source of interference. While a DOS attack is possible, it seems like a lot of trouble to go after one classroom. I would also recommend giving one 802.11a access point a try. Many will not be able to use it, but microwave ovens won't bother it much either. Howie Frisch [EMAIL PROTECTED] Michael Gregory wrote: Or maybe a DOS attack. Not only can an attacker unauthenticate a user but some Wireless management applications have defense mechanisms built in to protect their networks. An attacker can disrupt service from the protocol level. Remember that we talked about establishing associations to use the wireless network? If you can build an association, then there must be a way to disassociate. If you can authenticate, then there must be a way to unauthenticate. Unfortunately, in the IEEE 802.11b standard, both methods exist, and both methods do not require any authentication in the message. That means the attacker can send out a disassociate or unauthenticate message to an arbitrary wireless network user and disconnect them. This is a bad design from the protocol's perspective. Robinson, Ronald wrote: 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/.
Re: [WIRELESS-LAN] Spectrum Analyzer for interference detection
Or maybe a DOS attack. Not only can an attacker unauthenticate a user but some Wireless management applications have defense mechanisms built in to protect their networks. An attacker can disrupt service from the protocol level. Remember that we talked about establishing associations to use the wireless network? If you can build an association, then there must be a way to disassociate. If you can authenticate, then there must be a way to unauthenticate. Unfortunately, in the IEEE 802.11b standard, both methods exist, and both methods do not require any authentication in the message. That means the attacker can send out a disassociate or unauthenticate message to an arbitrary wireless network user and disconnect them. This is a bad design from the protocol's perspective. Robinson, Ronald wrote: 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/. begin:vcard fn:Michael Gregory n:Gregory;Michael org:Simon Fraser University;Network Operations adr:;; University Drive;Burnaby;B.C.;V5A 1S6;Canada email;internet:[EMAIL PROTECTED] title:Network Analyst tel;work:604 291 4532 tel;fax:604 291 4242 url:http://www.sfu.ca version:2.1 end:vcard
Re: [WIRELESS-LAN] Spectrum Analyzer for interference detection
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.DavidDavid MortonDirector, ITI Security SolutionsUniversity of Washington[EMAIL PROTECTED]tel 206.221.7814On 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 PMTo: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDUSubject: [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/.
RE: [WIRELESS-LAN] Spectrum Analyzer for interference detection
Title: Spectrum Analyzer for interference detection Ron, I would look for a micro wave oven or a 2.4 gig cordless phone near your classroom. Dwight Dwight L. Hazen Indiana University, UITS Bloomington, In. 47408-7378 812-855-5367 -Original Message- 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/.
RE: [WIRELESS-LAN] Spectrum Analyzer for interference detection
Title: Spectrum Analyzer for interference detection 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 PMTo: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDUSubject: [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/.
