Cisco Subnet An independent Cisco community View more

My Experence with Cisco Clean Air

Not a fart scrubber in the building 17 cafe like I thought....

Whenever I see a new product come on the market, I always wonder; "Who comes up with these names?" I would have LOVED to have been in the meeting when the names; 666 Cold and Flu Medication, Jos. A. Bank (who abbreviates a first name?). Although I like the name Microsoft Kin...reminds me of down home! I hope it comes with cornbread and fried tators! So when we were approached to do a TechWiseTV show on Cisco Clean Air, 44 years of built up experience in fart humor came rushing to the surface like a category 1000 tidal wave. Humor turned to disbelief pretty darn fast when the marketing folks told me what this product could do. No way in the world did I believe them. "You have actually and honestly built a spectrum analysis module into hardware on an access point." Really... I needed to talk to the folks that actually did this work in silicon before I believe it, because honestly, this sounds like a marketing sleight of hand where you say hardware, but REALLY mean in conjunction with some software. My first thought on how Clean Air worked was that they must have embedded a DSP into the core ASIC to handle the base level spectrum analysis operations since that would choke off a MIPS processor. You could possibly do this using MatLab to build it. If they stayed within 7K gates and compressed the code to minimize the ROM then that should still work at low power (POE or POE+). BUT that would not be scalable and multistreams, video or certainly Fast Fourier transform algorithm used in most wireless would choke it down. Well...that's not what they did at all. Not even close, well, I was kinda close on the DSP part. I talked with the glass jockeys in the illusive beige building (with the softest toilet paper on the entire Cisco San Jose campus) about this. They actually designed a total separate chip set they called a SAGE and a DAVE chip. It works like this: as wireless traffic is flowing through the SAGE the normal and classified traffic will flow through all happy and connecty like. When wireless traffic flows through SAGE chip that is outside of parameters, then it is passed up to the DAVE chip for analysis. The DAVE (DSP Vector Accelerator) is used to perform the high end filtering, decimation, rotation, sync-word detection, and modulation detection without burdening the main CPU. Long to short the DAVE handles CPU intensive signal processing operations which would choke down other wimpy CPUs. Then after all of that big time intensive single condition is done, the results are passed to the Sensord in the CPU where it looks at the frequency of interference bursting, and the actual attributes of those bursts. It gets down in the weeds to look at stuff like the modulation type of the burst and more. Then the Clean Air system gives you the straight scoop on where, what, when and how to fix the problem. All this happens in the background, when normal wireless communication is still happening. Wow man! I have got to see this in action. I invited fellow United States Navy vet Jim Florwick to bring his gear into TechWiseTV labs to kick the tires and light the fires. He didn't disappoint either. Well, he kinda did in that he didn't bring any beer. As any salty dog knows, brown shoe Navy ALWAYS brings beer to a black shoe Navy compartment. Davey Jones Rule of the Sea; Article IV section X. Anyway... We tested interface classification on the easy stuff like Bluetooth, rogue APs, misconfigs and appliances. As expected, they were picked up and classified immediately. No surprise or big deal for that matter. I broke out the big guns. A wireless frequency hopping jammer I built myself in the CodeCave that uses old 802.11 technology like 802.11FH, proprietary wireless and cancellation. Not only did it pick it up but it guessed it was some sort of custom jammer! Very cool. Jim wanted to try to break it also, so both of us threw everything we could at it and the system picked it up. Stuff like wireless distributed DoS, key jacking, jamming, video cameras, aluminum foil, area flooding, a combo of all of these at once etc. We had a continuous loop of video playing on 10 clients across the WLAN and without fail the clients stay worked oblivious to what was going on in the background. That was certainly cool. But what was most impressive was what I didn't see. The APs on the Clean Air system actually talk to each other to help eliminate false positives. If one AP picked up my jammer, the other ones although they could see it, did not report it. This is so friggen cool! Because chasing down wireless problems are like tracking ghost without a cheesey tv show. If each AP is reporting an anomaly somewhere, I am back to trigonometry 101 to figure out the hypotenuse of the coverage area...or is it the adjacent.. Like ole non beer buying Jim Florwick says; "You're breathing your physical layer" I like that dude. Tracking problems faster is all good. Another smokin' awesome feature is ability to connect the Cisco Spectrum Analysis software that has been on our laptops for troubleshooting to a remote AP to troubleshoot from a distance. Oh mercy is that a great feature. Now, the Clean Air solution can be a remote sensor anywhere it is placed and I can troubleshoot it from a hotel room clear across the globe if I need to with ease. All without causing disruption to a normal days processing. Now I can see the problems just like on a 85K USD Spect-An! Without having to ship one out or carry it through the airport. I have done this and actually brought a seat for my spect-an a few times. Although it's embarrassing when the spect-an gets upgraded and I do not. Well, long to short, Cisco Clean Air is the real deal. It is certainly one of the coolest products to come out of Cisco since the Nexus stuff. If you are looking to add to or deploy wireless, this is certainly worth your time to eval. As for TechWiseTV, we had so much fun with Clean Air; Robb cleaned it up and we taped Jim and I messing around with the system. As a shameless self promotion; check this show out on 20May10 at http://www.techwisetv.com hey it's time to get out of here and start the weekend. I hear those fish calling... someone else's name... Jimmy Ray Purser Trivia File Transfer Protocol The eyes of the mantis shrimp possess a feature that could make DVDs and CDs perform better. By emulating this structure, which displays color wavelengths at all ranges, developers could create a new category of optical devices.

Editors' Picks
Join the discussion
Be the first to comment on this article. Our Commenting Policies