I'll pile on the Meru praise bandwagon. We have a campus-wide 802.11n Meru single-channel deployment with about 150 AP's installed. Our experience matches with Kevin's. I can see that a more adaptive multi-channel architecture could be useful in some situations, as others have noted. Nevertheless, our actual experience with interference thus far has happily been "not an issue".
Ken Clipperton Director of Information Technology Midland Lutheran College From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:[email protected]] On Behalf Of Kevin Grover Sent: Tuesday, August 04, 2009 10:16 AM To: [email protected] Subject: Re: [WIRELESS-LAN] Single Channel vs Multichannel Architecture We are a Meru shop with 800+ ap's. The single-channel architecture have worked flawlessly for us. The single channel architecture has been very good neighbors to the traditional ap's that border us. I would echo what the other Meru users have said about being able to allow research and share the spectrum with other users. We have not seen any compatibility issues. The feature set has lagged on the management side of things but they appear to be catching up. Deployment was a snap and because of the single channel, if we find a dead spot we just throw up another ap. Our Account Rep and Field Engineer have been awesome. Support from Corporate has been good. We are pretty happy with our system and can't imagine going back to the three channel juggling act. Kevin Grover Network Team Leader Office of Information Technology Utah State University (435) 797-2401 From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:[email protected]] On Behalf Of Manoj Abeysekera Sent: Thursday, July 30, 2009 10:10 AM To: [email protected] Subject: Re: [WIRELESS-LAN] Single Channel vs Multichannel Architecture In my humble opinion I think both single-channel architecture and multi-channel architecture purely depend on the location (RF Environment). I've seen some solid test results from Meru, I also know some people who has gone with Meru with better results than two other giants, Dave Akin from CWNP program had also observed the (now famous "NOVURUM") test results of Meru and would bet his mortgage on it. At the same time I agree with Bruce if you have a very complex RF environment (and most of time you have to share this unlicensed frequency) single-channel (Meru) is coming little short. Whereas multi-channel architecture would give you more options and RRM (Cisco -Interestingly no one mentioned Cisco) or ARM from Aruba will let you with some easy maneuvering. Then again one could argue that if it is broad/spread-spectrum interference, then no one can save you. So the point i am trying to make is, it all depend on your location. If you are such a isolated edu with whole spectrum is at your mercy, then Meru would do a wonderful job. However if you are in the heart of a city center i would consider ARM to "steer" me clear. As i have professed before success of a WLAN deployment depend on two important things for most nonprofit edu's. * Location-based design (before and after choosing a vendor)(whether for whole campus or for one building) * Per-unit price (so that you could come up with "your" own requirement) (Uni's with disposable Income don't bother) Then come the feature-set and everything in between... Remember what we after is not "band-steering" or "channel-stacking". We after decent and stable Wi-Fi signal for our user community. my $.02 Manoj -------------------------------------------- P. Manoj Abeysekera, CWNA Network Engineer American University 4200 Wisconsin Ave, NW Washington DC. 20016 "Osborne, Bruce W. (NS)" <[email protected]> Sent by: The EDUCAUSE Wireless Issues Constituent Group Listserv <[email protected]> 07/30/2009 08:15 AM Please respond to The EDUCAUSE Wireless Issues Constituent Group Listserv <[email protected]> To [email protected] cc Subject Re: [WIRELESS-LAN] Single Channel vs Multi-Channel Architecture Jason, I wholeheartedly agree. We here at Liberty University spent a year evaluating wireless & NAC solutions. We chose to move from Cisco "fat" APs & Clean Access to Aruba's wireless & ECS NAC solutions. The real challenge is in dense environments. Meru's "single channel" becomes "channel stacking" aka multi-channel to provide additional bandwidth. You then have the client roaming issues again. Also, you cannot "steer" clients to load balance the clients across available resources. Aruba's ARM 2.0 has many options in this situation and solves many of the issues that Meru's architecture solves. With a single channel architecture, you are "stuck" if some interference appears in that RF range. The system may be able to change to another channel, but that WOULD CAUDE *all* the clients to roam. In a multi-channel architecture, only a small number of clients would be affected. There is obviously a reason why Meru is the _only_ vendor with single channel. All the others (including the largest players) use a multi-channel solution. If Meru's solution is so great, you would see others with single-channel too, even if they needed to license technology from Meru. Bruce Osborne Liberty University From: Jason Appah [mailto:[email protected]] Sent: Wednesday, July 29, 2009 1:44 PM Subject: Re: Single Channel vs Multi-Channel Architecture I agree wholeheartedly, the Aruba ARM works quite nicely, recently the neighboring hospital turned up its radios, and ARM switched us out without missing a beat. We reviewed Merus's devices and liked the approach, but were less than wowed with the completeness of the feature set. In the end we choose Aruba for four reasons: Price - pretty self explanatory Performance/deployment - (this was identical in most and in many of our use cases better than Meru) Feature Set - Aruba has obviously spent many hours actually listening to and implementing user centric changes, I don't know of a more feature rich wireless solution Support - Aruba has in many occasions been proactive, where I have posted a question to this forum and others to actually go out of their way to contact me to help me fix a problem, in some instances where the problem wasn't even Aruba's at all... We haven't looked back. From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:[email protected]] On Behalf Of Ken Connell Sent: Wednesday, July 29, 2009 9:15 AM To: [email protected] Subject: Re: [WIRELESS-LAN] Single Channel vs Multi-Channel Architecture I don't have much experience with a single channel deployment, but without even getting into vendor preferences or specifics I can't see how a single channel can gain any perfomance in such an unpreditctable and dynamically changing environment as far as other devices, and wireless networks that will come and go probably a daily basis with little or no control. The channel you decide on today, may not be the best suited channel tomorrow, and if you then need to make a change at that point, then you've jsut come full circle and are right back where you started. In my opinion it just makes sense to go with an automated RF type deployment (Aruba ARM for us) and be able to sleep at night ;) Ken Connell Intermediate Network Engineer Computer & Communication Services Ryerson University 350 Victoria St RM AB50 Toronto, Ont M5B 2K3 416-979-5000 x6709 ________________________________ From: Ryan Holland Date: Wed, 29 Jul 2009 09:04:34 -0400 To: <[email protected]> Subject: Re: [WIRELESS-LAN] Single Channel vs Multi-Channel Architecture ...interesting thread... When we were making our decision 3+ years ago, we discounted Meru primarily on scalability information in their RFP response. So unfortunately, we did not get a chance to bring them in for a demo. I am still quite skeptical about a single-channel architecture but believe I understand why it is promoted: to assist devices in roaming by creating a seemingly single BSSID. However, once we see more devices supporting standards such as 802.11k and 802.11r, such efforts, to me, are negated. Again, however, I have not had the opportunity to play with this gear, so [disclaimer]. We have been deploying Aruba for sometime and have learned a great deal about their technology, so I will caution the trusting of intelligent radio management solutions. Instead, I would suggest one utilize this technology while maintaining a tight supervision of it. Using Aruba with whom I am most experienced, their adaptive radio management (ARM) is quite powerful, as it allows for dynamic remodeling for channel and power based on the environment. This means that as other building tenants bring in their own wireless systems, our network can modify its channel configuration accordingly. Also, in the event of an AP failure, adjacent APs will likely perceive a lower aggregate signal strength of neighboring APs, boost their power, and thus help alleviate the loss of coverage from said failed AP. The reason I cautioned earlier is that many administrators simply "turn on ARM" and leave it. Doing so is assuming the defaults are applicable for all environments, which I would argue is not true for most educational institutions. Examples: the range of chosen transmit power is likely too expansive; the noise threshold at which an AP would change channels may be too low, especially for "research areas" like Illinois mentioned; the target coverage index may be too low for densely deployed installations or too high for sparsely deployed installations. Aruba is great in that administrators can configure different ARM profiles for all these different circumstances and use them suitably. But again, to just turn it on and expect it to "work" can lead to false assumptions. I would also add that there are still a lot of those that state static channel/power assignments is the best way to go. While I would agree that is true assuming the environment is identical at installation as it was during survey, it is incredibly likely that the environment will change and therefore negate the initial survey. Because our environments are largely unpredictable, I find a dynamic solution to be preferable. Now, if we had complete control over RF across campus, my opinion may be different. (Oh, and because people seem to be concerned with these sorts of numbers: ~5,000 APs, ~40 controllers). ========== Ryan Holland Network Engineer, Wireless CIO - Infrastructure The Ohio State University 614-292-9906 [email protected] <mailto:[email protected]> ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. <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/. <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/. <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/.
