Cisco’s CleanAir vs the Atheros vendors

Last week I attended Wireless Tech Field Day in San Jose. It had a heavy emphasis on spectrum analysis in that three of the vendors (Cisco, Metageek and Air Magnet) spoke about their SpecAn products. As I am currently studying for the CWAP exam I was particularly interesting in learning more about Cisco’s CleanAir product as I had not yet had a chance to see up close these APs and to hear about their features. My initial thoughts about Cisco’s presentation on in general for our group was that it with was overly marketing heavy with too many powerpoint slides and marketing misinformation and not enough in depth technical information that the delegates were seeking, I noticed that my other friends who knew more about the Cisco products were sitting largely silent with a glazed look on their faces throughout much of the presentation. They also refrained from bringing out any of the actual products for us to look at closely or providing, as HP did, a free form question and answer session showing a WCS and controller running the CleanAir APs. I believe that Cisco really missed a great opportunity here to show a group of enthusiastic and very technical WLAN professionals how compelling the features of the CleanAir product are at a technical level instead of marketing BS. I went in with an open mind to learn about this technology as I believed (and still do) that it is providing a real benefit to customers.

This blog post is largely the result of an interaction I had towards the end of the session with Jameson Blandford which was made to be off camera. I guess Cisco was concerned that somehow the information he would speak about was somewhat proprietary and they didn’t wish their competitors to know. Fair enough, I thought at first. It didn’t, however, end up being very much about their proprietary tech in CleanAir so much as a bashing session about why Cisco’s products were superior to the Atheros based SpecAn solutions promoted by their main competitor, Aruba. In the end I got sick of this line of attack and spoke up to disagree with the line of reasoning which was essentially that you _had_ to have CleanAir APs because having the SpecAn on the AP that was servicing clients was the only way to do spectrum analysis. I am not usually a person to buy into this kind of ‘my way is the only way to do something’ type reasoning as I know that the reason we have such a wide variety of WLAN vendors in the market in the first place is that different people have different needs and a single vendor just doesn’t have a lock on everyone’s needs in the first place. As an aside I have had disagreements with colleagues who also claim that there is only one _insert vendor name_ way to do things in whatever field they specialize in.

The main argument that was being provided by Cisco against the Atheros based vendors was that their dedicated SaGE chip in the CleanAir APs was able to get a much more detailed view of the wireless interference and differentiate between say bluetooth interference and a microwave oven. This is true. The way Cisco has designed their system in CleanAir enables the AP to not only see the difference but decide on what to do based on what they see. My point to here is that I am not sure this really matters. In the end to a WLAN client, interference is interference and they don’t really care about the source, just that when they see it they have to stop transmitting or receiving until the air is clear. It matters to the AP how long or how persistent the interference is as Cisco has designed their system to use that information to decide if the AP should change channels to get away from the interferer. The same thing can be achieved, however by the Atheros based systems even though they don’t have as detailed visibility into the type of interference in that by overlaying their SpecAn APs dispersed with their normal APs they can get information on how the interference is affecting the clients connecting to those APs. If they are obviously not transmitting or using lower rates to deal with the interference the software can make a decision to change channels. I would also counter this point with Cisco in that if an AP is unable to deal with the interference by changing channels you would still need an engineer to go with a portable SpecAn laptop to figure out what is going on.

I have had many interactions with clients about their WLAN needs. I would say the majority of them and most concerned if the product they are buying meets the needs of their users in providing a good experience when connected to the WLAN (usually they have at least one application driving the business case) and a close second to this is the overall cost of the solution reasonable. Some are willing to pay for additional features they see as necessary, others just want the cheapest thing that will do the job. Some, and I believe this is the minority, will stick with what they know even though its more expensive in the long run as they believe this will make their job easier. Spectrum Analysis is an added feature and when a customer believes this will enable them to provide a better end user experience, they will see it as something worth buying. As most network admins responsible for deploying APs will not have had a heavy exposure to Spectrum Analysis they will either need training to know how to use this feature or they will rely on a WLAN professional to advise them how best to use this information. I am of the opinion that by making this feature a part of the standard WLAN chipset as Atheros has done, this lowers the bar on making this particular feature something that most admins have knowledge of and makes it more accessible. To me, more knowledge and more people having the knowledge of this part of how WLANs work goes a long way towards making it so WLAN’s are not ‘magic’ to network admins. I believe we will one day have it so learning about RF is a standard part of learning about networks because wireless networks will be so ubiquitous that it will be more unusual to have a wired LAN servicing clients than wireless.

My take on the integration of Spectrum Analysis features into access points is that it is a plus in general for improving the ability of the WLAN administrator to see what is going on in his network in much the same way packet analysis helps wired networks. This is really a critical function that didn’t have a lot of visibility before Cisco rolled out this feature set. I applaud Cisco for both bringing this issue to the forefront and for using the high quality SaGE chipset from Cognio to do this.

I am skeptical of Cisco’s marketing strategy for this product, however. They seem to have placed the 3500 series in a position in the market where they are an expensive solution for many businesses that want to gain some spectrum analysis features but don’t have the budget to buy these APs and place them throughout their enterprises. Meraki and Aruba seem to be filling in this gap, with APs that although they may be based on a more generic Atheros chip, are still good enough when integrated with the appropriate software to identify and avoid major non-802.11 interferers. I expect to see Aruba and to a lesser extent Meraki fill this need for a cheaper solution and gain market share from Cisco with a strategy of selling their solution as an always-on overlay in much the same way Aruba sells their current WIPS solution.

I would also contend that Cisco is not replacing the need for a WLAN professional with knowledge of spectrum analysis and a laptop with either Air Magnet or Metageek Wi-Spy to go in and pinpoint what is going on at a deep level in the spectrum at a particular area of a site that is having persistent problems. This will continue to be the case for many years to come as although the CleanAir chips provide ongoing analysis and are powerful, Cisco has really missed the boat in letting their standalone product lag behind other SpecAn vendors in not having a USB form factor. Looking at the vendors producing these type of Spectrum Analysis products while we were at the Wireless Tech Field Day it was very obvious that they were not standing still in adding features and functionality to their products that Cisco had not considered when they acquired Cognio. Cisco has stagnated somewhat in comparison to the above two vendors in SpecAn feature sets.

I would advise any WLAN Professional considering deploying these APs to carefully consider the ROI of the solution compared to the several different overlay options from vendors such as Air Magnet, Motorola AirDefense and now Aruba and Meraki. Sure it means a less integrated strategy than making the whole WLAN Cisco based, but it may just be ‘good enough’ that you can still gain the advantages of having Spectrum Analysis capabilities without the pain in your wallet. Oh and by the way, you’ll still need to tell your boss that you should by that copy of Air Magnet Spectrum XT or Metageek Wi-Spy that you’ve had your eye on for a while now. I would add as well you should go get certified in analysis by taking a course and exam from CWNP as a Certified Wireless Analysis Professional (CWAP).

4 Responses to “Cisco’s CleanAir vs the Atheros vendors”

  1. wireless_bob says:

    I agree with your statement that the WLAN system can make a decision about changing channels based on simple measures of interference pretty much as well as it can with detailed sources of interference being identified. There might be a small (probably very small) advantage to being able to fine tune a system-wide channel plan more optimally if the interference sources are known in detail.

    However with either method, both Cisco and non-Cisco systems eventually require feet on the ground to track down the actual interference source and devise a plan to mitigate or eliminate that source. The only advantage the Cisco system supplies is knowing in advance just what the interferer is for which one is looking. This might not be sufficient advantage to justify the cost.

  2. Chad says:

    What are your thoughts on SE Connect mode? Wouldn’t that feature help with the need to go onsite to troubleshoot? Did Cisco even mention it last week in their presentation? I agree with your comments concerning Cisco’s marketing approach. They need to worry more about what their solution can do versus knocking what other vendors can’t do. Thanks for sharing!

  3. WildDev says:

    My thoughts are that SE Connect mode provides more detail for a remote engineer, and is useful when you just need a snapshot of what the AP sees at the site. This doesn’t, however, substitute for an engineer being able to have feet on the ground and walk around to figure out exactly what is causing the interference. Remember that the client and the AP are normally seeing different things in the environment and the end user experience is more related to the client’s view of things.

  4. takamine99 says:

    Great review. The other thing about Spectrum Analysis is that currently it is the 2.4GHz band that is so overcrowded. There are only 3 non-overlapping channels, so arguably when there is interference, there are only 2 other channels to move to. With the recent proliferation of smart phones, tablets and other 2.4GHz devices, it’s going to be difficult to keep the air clean. But I am with you 100%… Spec Analysis is a good tool, but you have to keep in mind what it is designed to do, and the extra features in the CleanAir solution may not justify the premium cost. And don’t look for this type of solution to displace pure Spec Analysis solutions (metageek, etc.).

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