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Wi-Fi Roaming 101

Wi-Fi roaming is often a tumultuous subject.  The crux of the issue is, with Wi-Fi the roaming decision is left to the client.

In the recent years, there have been great strides in improving Wi-Fi roaming with the creation of standards-based roaming technologies.  Cisco first pioneered fast roaming many years ago with CCKM (Cisco Centralized Key Management), which was the foundation for 802.11r.  11r which was ratified by the IEEE in 2008, allows for fast roaming, even on a secure 802.1X SSID.  With 802.11r it is possible to roam without disruption during a voice or video call.

While client support of 802.11r is largely lacking in the laptop space,  there is large support in the smartphone realm.  Apple iOS devices have supported 11r since iOS 6 (http://support.apple.com/kb/HT5535).  The recent Samsung smartphones, such as the Galaxy S4, S5, and Note 3, also support 11r.

Note: Some non-802.11r clients can react adversely when connected to an 11r WLAN.  The current recommendation from Cisco is to have a separate WLAN for 802.11r clients.

802.11k is another amendment from the IEEE that helps to improve roaming.  802.11k provides a whole slew of information to the client, which allows the client to understand the RF environment and make an informed roaming decision.  This information can include channel load and AP neighbor lists.

11r and 11k help, however, that does not mean the infrastructure is irrelevant in the roaming picture.  With the help of a model train, we did some testing to figure out just how much impact the infrastructure could have.  We compared Cisco to one of our competitors, whom we will call Vendor A.

This video summarizes the results and shows the train in action, or continue reading for more details:
Read More »

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802.11ac: That’s the Answer. What’s the question?

Everybody’s talking about 802.11ac, but we’ve sensed some confusion for next steps as far as how CIO’s and IT organizations should be approaching the new standard.

3700internal2Should I move to 802.11ac?

You’re probably thinking: Chris, you’re a leader at Cisco, of course you want me to migrate to 802.11ac. That, my friends, is where you are wrong. There is no simple answer to the question of whether you should move your network to 802.11ac. Here’s my simple rule of thumb:

There is no premium for 802.11ac from Cisco. If you are deploying new Access Points’s today, you should be buying 802.11ac. If you’re not buying, you are probably satisfied with your network and how it will handle the growth of more and more clients associating with your network and the bandwidth demands that come with that client demand. If you feel you have a plan to handle this demand, then you are one of the few that can pass on 802.11ac.

That said, there is a strong ramp up for Cisco 802.11ac products in the market, the AP3700 is the fastest ramping access point in our history and we have yet to see if the AP2700 will claim that crown in the coming months. ABI Research estimates that currently 50% of new device introductions are 802.11ac enabled, a statistic expected to increase to 75% by the end of 2015.  This is enough proof of the overwhelming interest in adding the benefits of 11ac to networks. Let’s take a step back and consider the basics of why people are moving to the new standard.

Why .11ac?

Today, everything is about getting what we want, when we want it. Instant gratification. It’s not just the millennials—we’ve all been conditioned to expect things within seconds. Could you imagine the days pre-Internet if you had the capability for on-demand movies? Read More »

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TU Darmstadt Rolls Out Cisco Unified Access to Prepare for 802.11ac

May 27, 2014 at 11:31 am PST

Technische Universität Darmstadt, usually known as TU Darmstadt is a research university based in Germany. It was founded in 1877 and over the last 137 years has grown to be among the largest and most prestigious public universities in Germany serving over 25,000 students per year. It is the alma-mater to many world-wide leaders from Nobel prize winners, a CEO of a fortune 500 company, a president of a country and multiple World Robocup champions.

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No wonder, they have a reference from Albert Einstein!

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In 2009 TU Darmstadt embraced BYOD with the 5508 Series Controller managing the 1140 802.11n Access Points. Recently we talked to Thomas Vogel, the Head of Network Group and Andreas Liebe, the Network Services Manager who have over 15 years of experience managing WLAN environments. In this blog, we will describe some of the details of WLAN deployments using the 3850 Series Switch and the 5760 Series Wireless LAN Controller to address the new requirements in the school environment. Read More »

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Portland State University rolls out 802.11n and 5760 Series Controller

May 5, 2014 at 10:46 am PST

Portland State University is Oregon’s largest and most diverse public university encompassing 50 city blocks, eight schools, 226 degree programs, 29,000 students, including 1,700 international students from 91 countries, and 126,000 alumni. For the second year in a row, the US News & World Report has named Portland State University a top 10 “up-and-coming” national university in its Best College rankings, released online Sept. 10.

In 2010 Portland was one of the first schools to adopt the Cisco CleanAir capable Access Points 3502 to address the frequent sources of interferences found in a typical school environment. In this blog, I will describe how the students adopt technology to learn as well as share some details about our conversation with Tamarack Birch-Wheeles, the manager of Network Team in charge of the WLAN deployment with the 5760 Series Wireless LAN Controller.

psu Read More »

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Wi-Fi & Taxes: Digging into the 802.11b Penalty

It’s that time of year again in the US – Tax Time!  That time of year where we review the previous year’s bounty, calculate what’s due, and re-evaluate our strategies to see if we can keep more of what we worked for.  Things change; rules, the economy, time to retirement, and before you know it you find yourself working through alternatives and making some new decisions.

Anyway, as I was working through the schedules and rule sheets, my mind wandered and I started to think about Wi-Fi and the taxes associated with it.  In my day job, I often play the role of forensic accountant.  Like a tax accountant, I’m always looking for a way to get more or understand why there isn’t more already.  So along those lines, lets talk about a little known tax that you may well be paying needlessly.  I’m talking of course about the dreaded 802.11b Penalty.

Wi-Fi protocols like 802.11b are referenced by standards committees for the workgroup that develops them.  In the 2.4 GHz spectrum, there is 802.11b, 802.11g, and 802.11n.  Back in 1997, 802.11b  was the first modern Wi-Fi protocol ratified by the IEEE and it allowed transmissions of 11 Mbps, a major jump forward from the previous 2 Mbps  that was possible with the original 802.11 standard.

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After 802.11b came 802.11a, and then 802.11g.  Both of these protocols where a radical departure from the simplistic 802.11b structure and employed Orthogonal frequency-division multiplexing (OFDM) modulation (now standard in every 802.11 protocol created since then).  OFDM allowed for Read More »

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