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 If you are you looking to deploy Microsoft Lync voice over Aruba WLAN in a campus or distributed enterprise environment with Hosted Lync or in the cloud, look no further. Aruba’s fresh off the press Lync Validated Reference Design (VRD) guide is your single source for Wi-Fi design and configuration to deliver the best Lync experience to your mobile users.




The first, and perhaps the easiest, is to look at designing your Wireless network like a big calculation. This begins to get quite complex with many variables, yet the idea behind it is simple enough.


Build your design by looking at a variety of factors that go into how many access points you might need. If you look at enough variables, it starts to feel like you might have a good handle on getting the proper result.


Let’s go through a simple example.


First, you have to pick the Access Point of choice. This will determine the capabilities and capacities that will be used further on in the calculations. Things like single band vs dual-band, supported channel widths in 5GHz, number of supported associations per radio, how many concurrent SSIDs, what you Basic Data Rates will be. This will give you available airtime to support client needs.


Next, you take into consideration detailed information about your client base. How many, what type, what 5GHz channels might be supported, channel width, supported spatial streams, supported MCS rates, etc.


Finally, you add into your monster calculation the types of applications and services that will need to be supported by your clients. TCP data rates needed, RTLS, VoIP, video conferencing, streaming video, etc.


Put all of this in a big massive spreadsheet – along with a bunch of assumptions and out drops a number of Access Points you’ll need in order to support those assumptions.


Don’t get me wrong, this is a great way to get a quick estimate and get in the ballpark with a Bill of Materials and a starting point for Access Points.


But it is still JUST A CALCULATION – it has nothing at all to do with the real world. Especially with the RF situation you are designing for.


The REAL way to design for Wi-Fi that just works, is to design around RF Contention areas. The total capacity of any high-density WLAN is totally dependent on being able to get the absolute most Frequency Reuse as possible.


Again, to reiterate: It is all about Frequency Reuse!


No matter what your calculation process yields in the way of Access Point counts… it all comes to naught if you can’t manage to get frequency reuse.


Now what do I mean by ‘Frequency Reuse’. In any given area, how many times can I reuse a specific frequency? Think of a large circular amphitheater, perhaps 100m across. (imagine about the size of an American Football field only in a circle). With all the seats arranged in concentric circles around a tennis court in the center.


How many Access Points will you need for Coverage in this arena? Think hard for a minute…


OK, you’ve had enough time. The answer is ONE!


You’d only need a single access point in such a facility and with an Omni antenna and high power setting (still below FCC limits) you could have all seats covered with say -70dBm of signal. Meaning, any seat in the arena could have someone sitting with a smartphone and have Wi-Fi access from a single Access Point.


That’s the way omni antennas work. And with nothing in the way between the Access Point on center court, and each and every seat. You’d have fantastic coverage. No seat would be more than 60m-70m from the AP and life would be great.


Well… not totally great… because you would be limited by the association count capability of the access point. Perhaps 250 total clients spread across two radios and you’d be at association max. This is nowhere near the amount of seats in the arena.


So the answer for Coverage is ONE… but that doesn’t meet the capacity requirements at all.


So, you triple the count and put three Access Points on center court. You’ve now got a radio on channels 1, 6, and 11 and you’ve tripled, the capacity on 2.4GHz and tripled the capacity in 5GHz with radios on channels 36, 44, 52.


But you are still nowhere near the capacity goals for number of access points that came from your monster calculation project.


Thus we run into the REAL design issue. How to get the most number of Access Points without causing co-channel interference. Because as soon as you have two AP’s on the same channel, they both see each other, and the clients see each other… because of how 802.11 works – they will all defer to each other in a large contention domain. Thus you added an extra access point, but didn’t gain any additional capacity – all the access points and clients on the same channel will share the bandwidth together.


This is why I try to emphasize it is all about Frequency Reuse. The goal of Wi-Fi design is to get the most number of AP’s you can without causing Co-Channel Interference and contention areas.


Thus, instead of using only calculation tools, you need to have in your toolkit arsenal, at least one tool that can do predictive RF analysis. You can use these ‘survey’- type tools to predict where your RF is going, and how to move AP’s around, choose different antennas, different power settings, and learn to use walls, floors, and other RF dense obstacles to design IN RF frequency reuse!


The next time you are thinking about Wireless LAN design remember… It’s not about the calculation as much as it is how to design IN Frequency Reuse.

A closer look at WiFi Security IE (Information Elements)

by 2 weeks ago - last edited 2 weeks ago

In this blog post George Stefanick breaks down IE (Information Elements) as it relates to WPA and WPA2/802.11i. 


There are only two front-runners in Gartner’s 2014 Magic Quadrant for Unified Communications: Microsoft in the top spot, representing the best-in-class multi-vendor school, trailed by Cisco, the poster child for single-vendor solutions..


Top 5 Accepted Solutions

by 4 weeks ago - last edited 4 weeks ago by Chief Airhead

solutions ahead.jpg  Top 5 Solutions for July - August


After taking a second look at a recently posted case study about Los Angeles Unified School District’s new 1:1 computing initiative, I counted over fifteen references to security and policy compliance. While a heavy emphasis was placed on an optimized learning environment, so was the idea of No Trust enterprise-class mobility.




Last week, we released ArubaOS 6.4.2 for Mobility Controllers.  This release adds a significant new feature - Web Content Classification - to the already powerful set of controls included as part of the Policy Enforcement Firewall.  Let’s take a look at what it does, and how to use it alongside our application visibility and control, or “AppRF”. 


Need for speed!!!

by on ‎08-12-2014 02:36 PM - last edited on ‎08-13-2014 10:15 AM by Chief Airhead

As I’m GoKarting my MINI around the city, I always gravitate towards the fastest or least congested lane. I'm the same way when it comes to Wi-Fi, always wanting to go faster.



Contending with Wi-Fi interference is like being stuck behind a slow driver in the fast lane. You can deal with it by honking, flashing your high beams or tailgating – none of which are recommended. Or you can simply change lanes and go around the problem.


Top 5 ClearPass Tutorials

by on ‎08-12-2014 10:00 AM


The community has been providing some very informative tutorials for our Mobility Hero Contest. These combined with tutorials posted by Aruba Employees give us amazing insight in how to do many things with ClearPass. See what 5 tutorials made my cut. 


Masters of the [Mobility] Universe

by on ‎08-11-2014 12:20 PM

In a prior post (The Technology is Right...) I stated what I believe to be the keys to getting mobility right. As I reviewed the post closely, I realized that I merely stated “what” and “why”. However, I never stated "who" must ensure that the organization gets mobility right. The answer may surprise you.
Linksys-Router.jpg                     f1-not-equal-sign.jpg               205-550_1.jpg

Rightsizing with the only complete 802.11ac portfolio in the market.

by on ‎08-07-2014 09:02 AM - last edited a week ago

With Aruba having the industry's only complete 802.11ac portfolio in the market, you can rightsize your WLAN by mixing & matching the best AP's for each area of your deployment based on your requirements.


The addition this month of these new 210 Series Access Points complete the portfolio of 4 platforms, enabling you to select the AP's to best fit your performance, density and cost requirements.



Inside BlackHat 2014 – Mid-show report

by Moderator on ‎08-06-2014 11:05 PM

Daily summary of Aruba's Wi-Fi network at BlackHat USA 2014



It may seem counter intuitive that maintaining the configuration of another firewall inside your network will save you time and make for a simpler, more scalable design, but bear with me for a few minutes and I will explain how Aruba’s PEF firewall and related features do just that.


En Garde!

by on ‎08-04-2014 09:30 AM

Based on what I have learned over the last few years regarding mobility and security, I propose some foundational guidelines for protecting any enterprise mobility environment.

4 Ways to Safeguard your Guest Network

by on ‎08-04-2014 09:08 AM

If your guest network purely uses a shared key or an open SSID, you can forget about security. Anyone can connect when they want, and you have no record or way to enforce restrictions.


The Forgotten Perimeter

by Moderator on ‎07-29-2014 03:38 PM

Isn't one firewall enough?  Let's look at how the Aruba Wi-Fi mobility firewall helps protect you from your biggest enemy - your users! 


5 takeaways from LA Unified School District’s move to 1:1 computing

by Moderator ‎07-23-2014 08:35 AM - edited ‎07-23-2014 10:31 AM

LAUSD.pngCan you imagine the scale and complexity of rolling out iPads or Chromebooks to 650,000 students across 900 schools? Not an easy task, but if Los Angeles Unified School District (LAUSD), the second largest school district in the U.S., can do it, any K-12 can!!


The district’s larger goal was to provide anytime, anyplace learning to each student. According to Shahryar Khazei, Deputy CIO of LAUSD, this meant “not only putting powerful tools in the hands of our students and teachers, but also building the appropriate infrastructure, including campus Wi-Fi, to support their use.”


Phase-1 of LAUSD’s one-to-one rollout was kicked off with 30,000 iPads across 47 schools.


Here are some tips & tricks from the LAUSD deployment that can be applied to school districts of all sizes.


A Tool's Got To Know Its Limitations

by on ‎07-16-2014 11:08 AM

One of the wonderful things about mobility and its related technologies is that, from the simple to the complex, you can learn something new everyday. In this post, I will address something that is relatively simple...
...virtual site surveys

Top 5 Airheads Conference Presentations of 2014

by on ‎07-14-2014 09:15 AM - last edited on ‎07-14-2014 04:55 PM by Chief Airhead

The Airheads conferences have so much great information and many great breakout sessions. This makes choosing the top 5 a monumental task, but we tackled the task and here is the Top 5 Airheads Presentations.


Poor Wi-Fi experiences on campus spread like wildfire

by on ‎07-10-2014 10:15 AM - last edited 2 weeks ago

You don’t want to get caught asleep at the wheel with poor Wi-Fi experiences and facing a social media train wreck that could hinder recruitment, student satisfaction, and learning outcomes.  





All Wireless Workplace series: Is the traditional office marching towards extinction?

by Moderator ‎07-08-2014 08:05 AM - edited ‎07-10-2014 02:19 PM

#GenMobile is redefining the “office” as we know it. The notion of a place of work will still be around; however the traditional office is bound for extinction. It is happening faster than we think and about a thousand IT professionals across the globe just validated it.




Gartner Confirms, Aruba has the Magic Touch

by Moderator on ‎07-02-2014 12:28 AM - last edited on ‎07-02-2014 07:00 AM by Chief Airhead

Last week Gartner muttered the word “Abracadabra,” and with a flash of light and a puff of smoke, the 2014 Magic Quadrant for Wired and Wireless LAN Infrastructure appeared. And it was magical. Well, sort of.




Login and Passwords fail


If you’ve conquered texting you’ll attest to the fact that bigger keyboards made your thumbs come alive. A few typos never stopped you from getting the message out. Unfortunately, using that same keyboard to enter login and passwords to access enterprise networks and applications requires repeated accuracy and patience.





Survey Says.....

by ‎06-25-2014 08:30 AM - edited ‎06-25-2014 03:07 PM

Are site Surveys Important?




by ‎06-20-2014 09:30 AM - edited ‎06-20-2014 10:46 AM

The BITS, BYTES and WIFi ....


There is a general misunderstanding around bits and bytes with most end users, especially when trying to measure WiFi performance.


Mbps (MegaBITS) are often referenced to measure transmission speeds.


Example: Comcast package




Example: speed test






Too close for comfort

by ‎06-18-2014 09:01 AM - edited ‎07-01-2014 10:36 AM

Did you know 802.11ac’s gigabit data rate requires devices to be very close to the AP?


Newer MCS8 and MCS9 modulations in 802.11ac offer increased performance and require higher signal-to-noise ratios. This means clients must be close to an AP at all times. But isn’t this a basic requirement for any wireless network?


Making sure that clients always associate with an AP with the strongest signal is not as easy as it sounds because clients make their own roaming decisions.


Now don’t go geek and start writing a mobile app that’ll find the closest AP. Chill! Aruba’s patented ClientMatch technology gets rid of the old sticky client problem and lots more.


To see whether this technology makes a difference in roaming, engineers at the testing firm Novarum conducted a high-density roaming evaluation between Aruba and Cisco.


Novarum painstakingly recreated a high-density mobile environment using 75 802.11ac clients and three 3x3:3 802.11ac APs – Cisco 3702i and Aruba AP-225. 


Results from the test clearly show that Aruba offers significantly better roaming performance, thanks to system-level capabilities like ClientMatch. Without it, the network is blind to the needs of its clients.





Help! I’m stuck

According to the test report, clients associated with an AP in a lobby and then roamed to an open space similar to a lecture hall, where clients could hear all the three APs.


As clients roamed, they were distributed pretty evenly across the three Aruba APs. But clients on the Cisco WLAN didn’t associate with a better AP as they roamed. Most got stuck on the first AP.


Screen Shot 2014-06-17 at 1.59.10 PM.png


Aruba ClientMatch was a huge differentiator in this test. It continuously gathers signal information from roaming clients and uses it to steer each one to the closest AP.


Overall system performance

Overall aggregate performance for Aruba was consistently 39%, higher than Cisco. The results are a bit deceiving for Cisco as one client got 120Mbps, which made it’s own roaming decision. All of the other clients struggled for airtime because they were stuck to the first AP.


Screen Shot 2014-06-17 at 1.49.15 PM.png 


Per-client throughput vs. number of clients

With Aruba, most clients enjoyed more than 4 Mbps throughput. With Cisco, more than 70% of the clients got less than 4Mbps. 


Screen Shot 2014-06-17 at 1.50.01 PM.png 


Lesson learned: 802.11ac alone cannot optimize client performance. You need technologies like ClientMatch, which can boost client performance by making sure they associate with the best AP as they roam. And if your clients get stuck, you’re probably using a Cisco AP.


For more detail on the actual testing take a look at the Novarum report or feel free to stop by the Proof of Concept (PoC) lab, Sunnnyvale CA.



The 802.11ac Shakedown

by Moderator ‎06-12-2014 12:06 PM - edited ‎06-12-2014 03:09 PM

In 2002, Aruba took on the Tasman Family by forming a company determined to deliver Wi-Fi as an alternative to the wire. 


Taking on the big guys is a relentless task and that’s why Novarum’s 802.11ac performance report is a breath of fresh air.  Free of strong-arm tactics, this report captures the performance differences in a real-world office environment between Aruba’s AP-225 and Cisco’s Aironet 3702i, 11ac Access Points. 


High-Density Throughput Test: Aruba is 2x Faster than Cisco.



Sometimes 3s a Crowd

by Moderator ‎06-04-2014 09:24 PM - edited ‎06-05-2014 01:05 PM

When properly designed, three-wheeled vehicles can deliver superior handling, performance, and greater fuel efficiency compared to their four-wheeled counterparts and greater stability and safety than their 2 wheeled-counterparts.  


However, not all designs are equal.  When improperly designed, three-wheeled vehicles can be tragic.  Take the Reliant Robin for example. A three-wheeled design catastrophe only a mother could love.  Watch the Reliant Robin in action. 





These same design principles also hold true for Access Points.  Like a car, an AP’s performance is tied to how well the AP is designed and how well the underlying components work together to provide an output that is greater than the sum of its parts.


Aruba’s AP-205 was purpose-built to bring the performance gains of 802.11ac at a cost-effective price point to high-density environments consisting predominately of single and dual-stream clients.  


SS clients.png


To validate the AP-205s design advantages in a high-density environment we decided to test it against Cisco’s brand new AP-2700, which is a 3x4:3SS AP. When we tested Cisco’s AP-3700, which boasts a 4th antenna, it didn’t come close to matching the performance of Aruba’s 3x3:3 AP-225.  We wondered if the AP-2700 had similar design flaws and would suffer the same fate as the AP-3700. 



Multi-client TCP Throughput Test

In this sixty-client test, the Aruba AP-205 delivered 46% faster downstream throughput and 33% faster bidirectional throughput than Cisco’s AP-2700. 





Small Packet Throughput Test (VoIP)

In this thirty-client test, we used packet sizes that are common in today’s networks running VoIP and latency sensitive applications. The AP-205 delivered 4.3x more traffic with 256B packets and 2.8x with 512B packets than Cisco’s AP-2700. 






Multi-Client 3 Stream Throughput Test

To put the AP-205 to the ultimate test, we decided to test with only 3-stream clients. Remember, the AP-205 is a 2x2:2SS and the Cisco 2700 is a 3x4:3SS.  As you can see below, the AP-205 outperformed the AP-2700 by delivering 40% faster downstream throughput in a test that favored a :3SS AP.  






Multi-Client Throughput Test using PoE

One of the design elements of the AP-205 was to deliver full 11ac performance in dense environments with 802.3af power. As shown in the chart below, the AP-205 delivered 45% greater throughput than the AP-2700 and none of the clients were starved nor hogged the air. With the AP-2700, over half the clients were starved of airtime and got less than 2Mbps. One lucky client got 43Mbps, but this came at the expense of other clients. 




Performance is a function of product design and the underlying components. Adding a third-spatial stream to an AP is akin to adding a 3rd wheel to a vehicle. If it’s not properly designed, it can lead to instability and poor performance, as evident in the AP-2700s test results. 




As you look to migrate to 802.11ac, be sure to take note of the devices on your network and don't be fooled by what's on the data sheet. Kick the11ac  tires and if you happen to be in the Bay Area, be sure to stop by 1344 Crossman and see for yourself how the AP-205 outperforms Cisco’s AP-2700. 


Test Bed Setup




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