Saturday, July 31, 2010

Using an open source RADIUS server in your Cisco wireless environment

I haven't personally setup a FreeRADIUS server in a Cisco wireless environment (I'm no Linux wiz), but there is a ton of documentation available online to guide you through each type of wireless security method, linking the FreeRADIUS server to an LDAP directory, and Cisco has published supported RADIUS attributes on their wireless LAN controllers.

Several Cisco NetPro postings deal with FreeRADIUS configuration issues as well.

All the different wireless security options are covered in the FreeRADIUS HOWTOs

FreeRADIUS is certainly a viable option for a budget restricted work place with good open source engineers.  Sometimes the cost of Cisco's ACS can stall the deployment of a project, or hold back the roll out of a secure wireless network simply due to budget constraints.

Someday I'll be at a point where I can stop & learn how to use open source software to complement existing Cisco deployments.  I still have two Perl books that I never had time to dive into - the project deadline didn't allot enough time to learn a new way to configure a bunch of autonomous APs quicker than I could do it with telnet & notepad.

    Thursday, July 22, 2010

    New YouTube Videos by Jerome - Wireless QoS

    You may already know this, but Jerome has posted three new videos covering wireless QoS.. (thanks to @the_wifi_guy for cluing me in!)

    Wednesday, July 14, 2010

    Rigs others have rigged

    The easiest way to show you the rigs that my ingenious co-workers have come up with to solve the problems associated with surveying outdoors/indoors and traveling with the necessary parts is to embed a slideshow of their efforts.  Thanks goes out to Jeff Russell (again) and Mike Rollison for sending me pictures of their creations!

    Tuesday, July 13, 2010

    Surveying for VoIP over Wifi for the Blackberry Bold

    This scenario was recently raised at work - the customer wants  us to survey a new wifi deployment to support Blackberry Bold phones as the wifi client.  What are the tx/rx stats of the Blackberry Bold, and how would you survey for a Blackberry Bold deployment?

    Luckily I work with a lot of super smart resourceful people - and it seems my pal Jeff Russell has come up with the information we need to make sure we can meet the needs of the Blackberry Bold 802.11 chip set.

    Jeff says: the Blackberry Bold according to the FCC website appears to have a Marvell chipset, and according to some information out there, Marvell provides the 3G chipset for many BB products. Here is an internal photo Jeff found online:

    The website where he found the photo is here: link

    Jeff says: this site indicates that the wifi chipset is a Texas Instruments WL1253B. A third-party website referenced the 1271/3 chipset, which is in the same product family, it just adds 802.11n to the fold.  Refer to page 28 of the following PDF: link
    It seems that the maximum 802.11b transmit power would be 17 dBm.  13 – 15 dBm for 802.11a/g/n rates.

    Sunday, July 11, 2010

    Oh, the rigs I've rigged..

    I used to travel with this raggedy carry on suitcase for the site survey gear, until I invested in a proper suitcase that can hold the survey kit on one side and a week's worth of my clothes on the other side..

    Old Raggedy Suitcase 

    New Suitcase Hotness

    This is my suitcase when it is fully loaded with 2 Tessco battery packs, all necessary mounting equipment and a Cisco 1142 access point.

    Over the years I've had to come up with all kinds of site survey mounting solutions for the Cisco 1240, 1130 and 1140 access points.  Luckily the 1130 and 1140 have similar mounting fixtures, and what has worked for the 1130 easily works for the 1140.

    For my first survey with a 1240, the customer wanted to ceiling mount the ap and use the AIR-ANT4941 dipole antennas, so I rigged up a wire harness to the back of the 1240 using phone wire.  I used the suspended ceiling clips that come with the 1240 to rig up a hook to hang the ap from the suspended ceiling grid while I was surveying.  Luckily the customer had some heavy duty wire, pliers and duct tape that I could use/borrow.  Flying to a customer site leaves you pretty unprepared to rig something up since you can't carry any tools with you.

    This is a rig I made for the 1240 ap out of a couple of coat hangers and some clear tape.

    This rig allows me to hang the 1240 off of a Wooster Wide Boy attachment (found at Lowe's) at the top of a Mr. Longarm (found at Home Depot) painters pole.  From there the external antennas can be duct taped to the arms of the Wooster.

    I don't have a picture of the survey cart all setup with a 1240 survey rig attached, but it looks something like this when it is all assembled.

    Coming up with a mounting solution for the 1130/1140 was a bit trickier since the ap is installed horizontally.  I got the idea from a friend who works for Cisco Advanced Services.  He uses a PVC floor scrubber attachment with the bristles removed, and the edges ground down to allow the attachment of the 1140 mounting bracket.

    I don't have a dremel to grind the PVC, so I opted for a wooden drywall tool attachment with the bristles removed for my survey rig.  The two angled adapters are used to put the 1130/1140 at the right angle for surveying.

    Using items found at any Home Depot make traveling to the survey location much easier.  The only tools I need to get before arriving at the customer location is the Mr. Longarm and a  fairly sturdy dowel rod.  I use the dowel rod to apply the ap number sticker to the suspended ceiling grid (with the help of a little tape).  I don't need a ladder if I have the dowel rod.

    As long as I can use some sort of rolling cart at the customer site, the painter's pole survey rig will work.  Most recently I used a furniture trolley as a survey cart.  Once when a cart wasn't available, I've even had to use a waiting room chair as a support for the painter's pole.

    Of course, the most insane thing I've done is climb a 20 foot ladder that was being stabilized by an enormous PVC elbow attached to the top of the ladder.  Never again.

    If you had to come up with a unique rig job so you can keep working, I'd love to hear about it.. let's not all reinvent the wheel eh?

    MetaGeek Chanalyzer Pro - Beta Testing

    Mark Yensen from MetaGeek sent me a Wi-Spy dBx to do some beta testing of their Chanalyzer Pro application, so I thought I'd pit it against the application I use most often for spectrum analysis - Cisco Spectrum Expert.

    At first glance, the Chanalyzer application was very impressive, especially with the Wi-Spy dBx price point of $599.00.  I liked the device signatures collected in Chanalyzer showing the visual patterns generated by devices operating in the 2.4 or 5GHz frequencies.

    The beta version of Chanalyzer Pro that I've been trying out doesn't have the device recognition turned on yet - but when Chanalyzer Pro is out of beta, this will be functioning.  The device recognition feature will call out devices whose RF patterns are known to the Chanalyzer Pro application based on a given RF 'signature'.  The list of known devices will grow based upon data sent in by end users of the MegaGeek Chanalyzer application.  As end users submit more and more data about RF devices, the repository of known devices will grow and will be shared with all Chanalyzer Pro users.

    A 'confidence level' will also be attributed to patterns recognized by the device recognition feature.  Many devices capable of RF transmission in the 2.4 or 5Ghz ranges can have similar RF patterns, and the confidence level will indicate the reliability of the device identification feature.

    Both the Chanalyzer Pro and the Cisco Spectrum Expert have a display of the RF spectrum that looks similar, and can be interpreted similarly.  The Cisco Spectrum Expert has the 'Swept Spectrogram' and Chanalyzer Pro has the 'Waterfall View'.

    There are a boatload of videos by Trent @ MetaGeek up on Youtube - I didn't realize this until just yesterday.. Thanks Trent for giving me a private tour of Chanalyzer Pro, when you could have pointed me to your YouTube channel just as easily :)  I appreciate you taking time out of your day to show me around Chanalyzer Pro.

    The Chanalyzer Pro is a great application, it does nearly everything that the Cisco Spectrum Expert application does, at a much lower price point.  Chanalyzer Pro has a 'report builder' template that allows you to easily embed spectrum analysis screen captures and other spectrum analysis data into an RTF, HTML or PDF document.  I have to manually capture screen images from the Cisco Spectrum Expert in order to put them into a customer facing deliverable, and the device listing export is only to a .csv file.

    I made a YouTube video showing the differences between the two applications, or as much as I could cram into ten minutes..  Let me know if you have any questions, I'll be glad to answer them.