Monday, July 9, 2018

A Healthcare WLAN build from start to finish - and why it should be built as designed

In March of 2015, I did a blogpost “5GHz WLAN Site Survey AP power settings - What you want, don't want, and don't care about.”  In this post, our goal was to find out the best minimum and maximum transmit power setting of a particular access point’s 5 GHz radio.  That post can be found here: http://justdowifi.blogspot.com/2015/03/5ghz-wlan-site-survey-ap-power-settings_7.html

We needed to determine the Wi-Fi coverage area of the access point at a particular transmit power that was going to be deployed in a building on a large hospital campus.  This coverage area data was used to model the WLAN using Ekahau’s Site Survey software.  In the blog post from 2015, we determined that the min/max transmit power would be 8 dBm and 14 dBm, respectively, and would provide the following -67 dBm cell coverage:



When modeling a WLAN with Ekahau’s ESS software, we need to choose a wall type.  In order to properly determine wall type/attenuation value, you need to measure the attenuation of the walls/doors/floors, etc.  This technique is taught in the Ekahau ECSE class and has probably been explained in a few WLAN Engineer blogs.  In the past I used a battery powered access point, but now I use an Odroid for that job.  More on that Odroid can be found here: http://www.morefrag.com/odroid/Odroid%20WLPC%20Excercises%20%5BFinal%5D.pdf  Other WLAN Designers/Engineers are using a new and improved single board computer, which can be found here: http://www.wlanpi.com/
Basically, you need a signal source – in my case, the battery operated Odroid and something to read the signal strength on the other side of the wall.  My wall measuring kit contains an Odroid single board computer, a Leica laser measuring tool to get accurate distances, a Netscout Aircheck G2 to read the signal strength, and of course, a clipboard with the floor plans on them for me to write on.  I bought the zipper case, the foam, etcetera, and made my own carrying case with places for everything to go so that I would notice when I forgot to put something back in its place.  I find it is the easiest way to not leave some of my tools behind.  Here’s my kit:

Use the signal source and signal strength meter to measure the RF attenuation in free space (about 20-25 feet apart) and then with a wall between the source and meter.  Same goes when measuring floor attenuation – bring the meter to the room beneath you and read the signal strength.  You can do the math to figure out how much attenuation is in the wall/floor and that information can be used when modeling and designing your WLAN.  This is outlined below.

Place your signal source in an office and walk through the open door into the hallway and measure the signal with your meter.  For this example, let’s say your signal meter reads -56 dBm.  Now move your signal source to the other side of the room, away from the door, and walk back to the hallway, closing the door behind you.  While standing in the hallway, opposite from the signal source, read your meter.  If your meter now reads -59 dBm, you know that your wall has 3 decibels of attenuation.  You may find a small tripod works well for consistency when positioning your RF source.  The image shamelessly boosted from one of Devin Akin’s presentations.



You will need to annotate the wall attenuation values however you see fit.  This information will be used later, so standardize how you do it so you’ll remember what your symbols mean.  When you feel you know the attenuation value of the different kinds of walls, you can then use the data to model your WLAN design.  If you have CAD files, you can import them for your project and you can assign attenuation values of the walls at that time and always modify as needed afterwards.


We looked at the construction of the facility and determined the wall types – most all of the walls were 3 dB since this was a wing with patient rooms and construction was similar throughout.

In healthcare, wall measurements can be tricky.  Most every hospital I have designed Wi-Fi for has been under some sort of renovation at that time.  Imaging departments, Operating rooms and other areas must not be overlooked when measuring wall types – assuming the entire hospital has 3 dB walls could be a costly mistake.  Many office areas have lead in the walls because the area used to be an imaging department.  During the renovation, the lead was never removed.  MRI areas are usually enclosed with a metal mesh, and block RF from going through.

Since many hospitals use location based WLANs to triangulate assets, we typically design the facility to meet those requirements.  This usually means we start at perimeter of the facility and work our way in when designing the wireless network.  We typically design to a given signal strength (RSSI) for the RTLS solution, combined with capacity calculations from our voice and data requirements.

Many large organizations with thousands of access points never statically employ the power and channel plan that was is in the original WLAN design.  The design often turns out to be “this is what your WLAN could look like if you follow these directions,” however most organizations simply choose a channel width, channel lineup and min/max transmit power and let RRM take care of the channel plan.  This is the case with this design as well.
This WLAN was designed almost three years ago, and is now built and up and running.  The power and channel plan is being controlled by RRM, and the WLAN Validation survey was completed recently with Ekahau ESS and the Sidekick.

Here is an overview of the Network Issues from our 5 GHz, 20 MHz channel width WLAN design.  The purple areas are the areas highlighting the areas where we have overlapping channels.  Notice that most of the channel overlapping occurs in hallways or other open areas where the RF is not attenuated as much.



Here is the same Network Issues view from within ESS of the Validation Survey.  The Validation Survey is a WLAN survey of what is actually built and up and running.



You may be thinking, “hey, wait a minute! Why are they different?”  The answer is “what is deployed is not actually what was designed.”  If we take the original design and modify the channel plan to match what RRM is doing, look what happens:



Look familiar?  Of course it does!  We have now modified our WLAN design to mimic what RRM is going, and they show similar results.  This is actually good news!  This means that we got it right.  From this point on, we are going to compare our design (using RRM’s channel plan) to the validation survey to see if they are similar.  If so, we know we did our design correctly.

Let’s look at a few other views, comparing what was design to what is actually up and running.
The graphic on the left is from the APoS survey, the one on the right is from the Validation Survey.  They match – now that’s good news!


This design had a requirement for what is known as “Secondary Coverage.”  Secondary coverage is a typical requirement for VoWi-Fi handsets so they can roam properly throughout a facility.

Here is our designed Secondary Coverage:


Here is our Validation Survey’s Secondary Coverage: (They’re pretty close).


For those of you who have access to Cisco Prime Infrastructure, you may have heard WLAN Engineers state that we want to see “mostly 3’s and 4’s” on our Cisco Prime maps.  If you are curious how much power is on each access point, see my previous post on Cisco 3802i series power levels.  The post with the power levels can be found here: http://justdowifi.blogspot.com/2018/07/cisco-3802i-series-power-levels.html


Now that we have shown that our implemented wireless network matches our modified designed network by matching the design to the actual implementation, let’s see how a nicely designed network can be implemented incorrectly.  Keep in mind this is the same design we started out with.  Here’s the design at 11 dBm transmit power, UNII bands 1,2 &3, with 20 MHz channels.


First off, we’ll make it better by including more channels in the lineup.  We will incorporate some of the U-NII-1, 2a, 2c&3 channels.  Notice the channel overlap literally disappears!  The purple color indicates channel overlap.



Using the same channel lineup as the original design, I am going to “virtually” login to the WLAN controller and turn on 40 MHz channels.  Look what happens!


Keep in mind that channel overlap is not a good thing.  Reconfiguring a WLAN without actually going into the original design and running some “what-if’s” could negatively affect your wireless network.

Another thing to mention is the channel overlap doesn’t always come from your access points.  If you are in a metropolitan area with older buildings, your 40 MHz and 80 MHz channels might interfere with your neighbors across the alley and the floors above and below you, depending on the age/construction of the building.  If your access points are interfering with your neighbors that likely means their access points are interfering with yours as well. Using a 20 MHz channel plan in a dense environment may actually increase your throughput!



Saturday, July 7, 2018

Cisco 3802i series power levels

For those of you in Cisco shops and need to know the power level of the access point when on different channels, this post is for you.

This is a list of the Cisco 3802i power levels per Channel scraped from the WLAN controller.

 

Channel 36

       Tx Power

      Num Of Supported Power Levels ............. 8

      Tx Power Level 1 .......................... 22 dBm

      Tx Power Level 2 .......................... 19 dBm

      Tx Power Level 3 .......................... 16 dBm

      Tx Power Level 4 .......................... 13 dBm

      Tx Power Level 5 .......................... 10 dBm

      Tx Power Level 6 .......................... 7 dBm

      Tx Power Level 7 .......................... 4 dBm

      Tx Power Level 8 .......................... 2 dBm

     

 Channel 40

    Tx Power

      Num Of Supported Power Levels ............. 8

      Tx Power Level 1 .......................... 22 dBm

      Tx Power Level 2 .......................... 19 dBm

      Tx Power Level 3 .......................... 16 dBm

      Tx Power Level 4 .......................... 13 dBm

      Tx Power Level 5 .......................... 10 dBm

      Tx Power Level 6 .......................... 7 dBm

      Tx Power Level 7 .......................... 4 dBm

      Tx Power Level 8 .......................... 2 dBm

             

Channel 44

Tx Power

      Num Of Supported Power Levels ............. 8

      Tx Power Level 1 .......................... 22 dBm

      Tx Power Level 2 .......................... 19 dBm

      Tx Power Level 3 .......................... 16 dBm

      Tx Power Level 4 .......................... 13 dBm

      Tx Power Level 5 .......................... 10 dBm

      Tx Power Level 6 .......................... 7 dBm

      Tx Power Level 7 .......................... 4 dBm

      Tx Power Level 8 .......................... 2 dBm      

     

Channel 48

    Tx Power

      Num Of Supported Power Levels ............. 8

      Tx Power Level 1 .......................... 22 dBm

      Tx Power Level 2 .......................... 19 dBm

      Tx Power Level 3 .......................... 16 dBm

      Tx Power Level 4 .......................... 13 dBm

      Tx Power Level 5 .......................... 10 dBm

      Tx Power Level 6 .......................... 7 dBm

      Tx Power Level 7 .......................... 4 dBm

      Tx Power Level 8 .......................... 2 dBm

 

Channel 52

    Tx Power

      Num Of Supported Power Levels ............. 6

      Tx Power Level 1 .......................... 17 dBm

      Tx Power Level 2 .......................... 14 dBm

      Tx Power Level 3 .......................... 11 dBm

      Tx Power Level 4 .......................... 8 dBm

      Tx Power Level 5 .......................... 5 dBm

      Tx Power Level 6 .......................... 2 dBm

     

Channel 56

    Tx Power

      Num Of Supported Power Levels ............. 7

      Tx Power Level 1 .......................... 18 dBm

      Tx Power Level 2 .......................... 15 dBm

      Tx Power Level 3 .......................... 12 dBm

      Tx Power Level 4 .......................... 9 dBm

      Tx Power Level 5 .......................... 6 dBm

      Tx Power Level 6 .......................... 3 dBm

      Tx Power Level 7 .......................... 2 dBm

     

Channel 60

Tx Power

      Num Of Supported Power Levels ............. 7

      Tx Power Level 1 .......................... 18 dBm

      Tx Power Level 2 .......................... 15 dBm

      Tx Power Level 3 .......................... 12 dBm

      Tx Power Level 4 .......................... 9 dBm

      Tx Power Level 5 .......................... 6 dBm

      Tx Power Level 6 .......................... 3 dBm

      Tx Power Level 7 .......................... 2 dBm

     

Channel 64

    Tx Power

      Num Of Supported Power Levels ............. 7

      Tx Power Level 1 .......................... 20 dBm

      Tx Power Level 2 .......................... 17 dBm

      Tx Power Level 3 .......................... 14 dBm

      Tx Power Level 4 .......................... 11 dBm

      Tx Power Level 5 .......................... 8 dBm

      Tx Power Level 6 .......................... 5 dBm

      Tx Power Level 7 .......................... 2 dBm

     

Channel 100

    Tx Power

      Num Of Supported Power Levels ............. 6

      Tx Power Level 1 .......................... 17 dBm

      Tx Power Level 2 .......................... 14 dBm

      Tx Power Level 3 .......................... 11 dBm

      Tx Power Level 4 .......................... 8 dBm

      Tx Power Level 5 .......................... 5 dBm

      Tx Power Level 6 .......................... 2 dBm

     

  Channel 104

    Tx Power

      Num Of Supported Power Levels ............. 7

      Tx Power Level 1 .......................... 18 dBm

      Tx Power Level 2 .......................... 15 dBm

      Tx Power Level 3 .......................... 12 dBm

      Tx Power Level 4 .......................... 9 dBm

      Tx Power Level 5 .......................... 6 dBm

      Tx Power Level 6 .......................... 3 dBm

      Tx Power Level 7 .......................... 2 dBm

     

Channel 108

    Tx Power

      Num Of Supported Power Levels ............. 7

      Tx Power Level 1 .......................... 18 dBm

      Tx Power Level 2 .......................... 15 dBm

      Tx Power Level 3 .......................... 12 dBm

      Tx Power Level 4 .......................... 9 dBm

      Tx Power Level 5 .......................... 6 dBm

      Tx Power Level 6 .......................... 3 dBm

      Tx Power Level 7 .......................... 2 dBm

     

Channel 112

Tx Power

      Num Of Supported Power Levels ............. 7

      Tx Power Level 1 .......................... 19 dBm

      Tx Power Level 2 .......................... 16 dBm

      Tx Power Level 3 .......................... 13 dBm

      Tx Power Level 4 .......................... 10 dBm

      Tx Power Level 5 .......................... 7 dBm

      Tx Power Level 6 .......................... 4 dBm

      Tx Power Level 7 .......................... 2 dBm

     

Channel 116

    Tx Power

      Num Of Supported Power Levels ............. 7

      Tx Power Level 1 .......................... 18 dBm

      Tx Power Level 2 .......................... 15 dBm

      Tx Power Level 3 .......................... 12 dBm

      Tx Power Level 4 .......................... 9 dBm

      Tx Power Level 5 .......................... 6 dBm

      Tx Power Level 6 .......................... 3 dBm

      Tx Power Level 7 .......................... 2 dBm

     

Channel 120

    Tx Power

      Num Of Supported Power Levels ............. 7

      Tx Power Level 1 .......................... 18 dBm

      Tx Power Level 2 .......................... 15 dBm

      Tx Power Level 3 .......................... 12 dBm

      Tx Power Level 4 .......................... 9 dBm

      Tx Power Level 5 .......................... 6 dBm

      Tx Power Level 6 .......................... 3 dBm

      Tx Power Level 7 .......................... 2 dBm

     

Channel 124

    Tx Power

      Num Of Supported Power Levels ............. 7

      Tx Power Level 1 .......................... 18 dBm

      Tx Power Level 2 .......................... 15 dBm

      Tx Power Level 3 .......................... 12 dBm

      Tx Power Level 4 .......................... 9 dBm

      Tx Power Level 5 .......................... 6 dBm

      Tx Power Level 6 .......................... 3 dBm

      Tx Power Level 7 .......................... 2 dBm

     

Channel 128

    Tx Power

      Num Of Supported Power Levels ............. 7

      Tx Power Level 1 .......................... 18 dBm

      Tx Power Level 2 .......................... 15 dBm

      Tx Power Level 3 .......................... 12 dBm

      Tx Power Level 4 .......................... 9 dBm

      Tx Power Level 5 .......................... 6 dBm

      Tx Power Level 6 .......................... 3 dBm

      Tx Power Level 7 .......................... 2 dBm

     

Channel 132

    Tx Power

      Num Of Supported Power Levels ............. 7

      Tx Power Level 1 .......................... 18 dBm

      Tx Power Level 2 .......................... 15 dBm

      Tx Power Level 3 .......................... 12 dBm

      Tx Power Level 4 .......................... 9 dBm

      Tx Power Level 5 .......................... 6 dBm

      Tx Power Level 6 .......................... 3 dBm

      Tx Power Level 7 .......................... 2 dBm

     

Channel 136

    Tx Power

      Num Of Supported Power Levels ............. 7

      Tx Power Level 1 .......................... 20 dBm

      Tx Power Level 2 .......................... 17 dBm

      Tx Power Level 3 .......................... 14 dBm

      Tx Power Level 4 .......................... 11 dBm

      Tx Power Level 5 .......................... 8 dBm

      Tx Power Level 6 .......................... 5 dBm

      Tx Power Level 7 .......................... 2 dBm

     

Channel 140

    Tx Power

      Num Of Supported Power Levels ............. 7

      Tx Power Level 1 .......................... 20 dBm

      Tx Power Level 2 .......................... 17 dBm

      Tx Power Level 3 .......................... 14 dBm

      Tx Power Level 4 .......................... 11 dBm

      Tx Power Level 5 .......................... 8 dBm

      Tx Power Level 6 .......................... 5 dBm

      Tx Power Level 7 .......................... 2 dBm

     

Channel 144

    Tx Power

      Num Of Supported Power Levels ............. 7

      Tx Power Level 1 .......................... 20 dBm

      Tx Power Level 2 .......................... 17 dBm

      Tx Power Level 3 .......................... 14 dBm

      Tx Power Level 4 .......................... 11 dBm

      Tx Power Level 5 .......................... 8 dBm

      Tx Power Level 6 .......................... 5 dBm

      Tx Power Level 7 .......................... 2 dBm

     

Channel 149

    Tx Power

      Num Of Supported Power Levels ............. 7

      Tx Power Level 1 .......................... 19 dBm

      Tx Power Level 2 .......................... 16 dBm

      Tx Power Level 3 .......................... 13 dBm

      Tx Power Level 4 .......................... 10 dBm

      Tx Power Level 5 .......................... 7 dBm

      Tx Power Level 6 .......................... 4 dBm

      Tx Power Level 7 .......................... 2 dBm

     

Channel 153

    Tx Power

      Num Of Supported Power Levels ............. 8

      Tx Power Level 1 .......................... 23 dBm

      Tx Power Level 2 .......................... 20 dBm

      Tx Power Level 3 .......................... 17 dBm

      Tx Power Level 4 .......................... 14 dBm

      Tx Power Level 5 .......................... 11 dBm

      Tx Power Level 6 .......................... 8 dBm

      Tx Power Level 7 .......................... 5 dBm

      Tx Power Level 8 .......................... 2 dBm

     

Channel 157

    Tx Power

      Num Of Supported Power Levels ............. 8

      Tx Power Level 1 .......................... 23 dBm

      Tx Power Level 2 .......................... 20 dBm

      Tx Power Level 3 .......................... 17 dBm

      Tx Power Level 4 .......................... 14 dBm

      Tx Power Level 5 .......................... 11 dBm

      Tx Power Level 6 .......................... 8 dBm

      Tx Power Level 7 .......................... 5 dBm

      Tx Power Level 8 .......................... 2 dBm

     

Channel 161

    Tx Power

      Num Of Supported Power Levels ............. 8

      Tx Power Level 1 .......................... 23 dBm

      Tx Power Level 2 .......................... 20 dBm

      Tx Power Level 3 .......................... 17 dBm

      Tx Power Level 4 .......................... 14 dBm

      Tx Power Level 5 .......................... 11 dBm

      Tx Power Level 6 .......................... 8 dBm

      Tx Power Level 7 .......................... 5 dBm

      Tx Power Level 8 .......................... 2 dBm

     

Channel 165

Not supported

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Friday, September 8, 2017

Using your WLPC Odroid for APoS and wall attenuation measurements

If you are a WLAN professional, you have probably heard about other Wi-Fi Engineers using wall attenuation values when modeling the WLAN during your Ekahau ESS software to design the project.  Short story, instead of using the default values in the software or doing a full AP-on-a-stick survey, the engineer takes a signal source and meter on-site and “measures” the wall attenuation to properly model and design the WLAN. 

 

I was recently on-site during construction of an extremely large, brand new hospital – with the intention of measuring the wall attenuation values since construction was at the point where we could do so.  In the past, I used a Buffalo access point that was powered by a cell phone charger – however this time I had an Odroid that I borrowed from a friend that attended the WLAN Professionals conference earlier this year.  At the conference, they built and configured an Odroid single board computer that did all kinds of nifty things that a WLAN Engineer might want.

 

If you have never been to a WLAN Professionals conference, I urge you to check it out.  Browse here for more informations.  https://www.wlanpros.com/thewlpc/

 

For more information on the odroid at the conference, here is the link:

 

https://www.wlanpros.com/maker-session-odroid-throughput-test-computer-build-configure-testing-jerry-olla-ferney-munoz-wlpc-phoenix-2017/

 

Now back to measuring wall attenuation!  In the past, I used a Buffalo access point and my Netscout Aircheck G2 to get the job done.  If you own Ekahau ESS and are not sure how to measure wall attenuation, the process of measuring walls is taught in the Ekahau ECSE class. 

 

This time, I had the Odroid on a battery, along with @WiFi_Princesa at the helm of the G2 and my Android with Wi-Fi Analyzer on my clipboard.  During the wall measuring process, I discovered that I was getting the same decibel values that I would expect if I was doing an AP-on-a-stick survey.  I did not expect the same results, since I assumed the Odroid would have a much smaller footprint than an actual enterprise access point’s coverage area.

 

That got me thinking.  I wanted to know the actual coverage area of the Odroid so I could compare it to an enterprise access point, such as a Cisco 3602i series.  When I do an AP-on-a-stick survey, I normally set my AP to channel 36, with a power level of 3.  I equate the power level of 3 to approximately 11 dBm.

 

I took the Odroid to a validation survey the following day, and set the AP on the ceiling to a 20 MHz channel width with a power level of 3.  I set the Odriod directly beneath the AP, and proceeded to do my validation survey.  After playing with the output power of the Cisco AP on the ceiling, I determined that the Odriod has the same coverage pattern as a Cisco AP on UNII-1 with power level of 3.

 

Here are the heat maps of the Cisco 3602i and the Odroid.  Conclusion – I think I can use an Odroid to simulate a Cisco 3602i’s coverage pattern when doing both APoS and wall attenuation measuring missions.

 

Here is the Cisco 3602i at  -65 dBm

 

 

 

Here is the Odroid at  -65 dBm

 

 

 

What do you think?  Will you use an Odoid to simulate an enterprise AP?

 

 

 

 

 

Friday, June 2, 2017

Converting your 5520 to a 5508 WLAN controller configuration

 

The goal of this document is to assist you (a Network Engineer that is comfortable navigating your WLAN Controller) in upgrading your WLAN controllers.  In this example, we will migrate from a 5508 WLAN controller to a 5520 WLAN controller.  The operating systems are different, and therefore the commands are as well.

There is an online tool that allows you to backup your existing configuration and run it through a migration tool which will give you the output you need to configure the replacement platform.

That tool can be found here: https://cway.cisco.com/tools/WirelessConfigConverter/

The tool will allow you to migrate wireless controllers to or from accross any of these platforms: 2500/5500/7500/8500/WISM2/3650/3850/4500 S8E/5760

In this example, we will need to upload the "show run-config commands" output or TFTP config backup from the 5508.  I'll use the TFTP option.  Start your TFTP server application on your desktop and browse to your WLAN Controller and instruct it to send a backup to your TFTP server.  You will have to use your IP address, not mine, and the naming convention that makes sense to you.  I use the IP address and date.

Your TFTP server should have received the file after a few minutes.  If not, check your firewall on your desktop.

 

Now browse to the URL mentioned above and the page below should load.  You'll need a CCO login to get to the tool.

Take the file that you received from your WLAN controller via the TFTP server and drag and drop it onto the center of the page where it reads, "Drop file here".

Now you need to look at the drop down above the "Run" button.  You need to select what you are converting from and what you are going to.  It is easy to miss, which is why I mention it.  Translation - I missed it.

Then click Run.  Your config should be below the Run button after you do it.  It might take a little bit of time, so don't panic.

Pay attention to the section that starts with, "Following configurations are encrypted on a 5508; 5520 can't understand them. Please consider reconfiguring them."  You will need those keys to bring your controller into production.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~END~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Following configurations are encrypted on a 5508; 5520 can't understand them. Please consider reconfiguring them.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~START~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

config radius auth add encrypt 4 10.15.20.2 1812 p <output snipped>

Cisco 1532 PoE options

 

Many times when researching product information, we come up with multiple documents that sometimes state conflicting information. 

The point of writing this is simple.  If you are a networking professional, know what you are deploying.  Reading product documentation is not enough - we must thoroughly test the product for the environment we are going to use it in.  If you want  to deploy the latest Meraki access point, ask them and they will send it to you - if you don't want it, they'll let you send it back. 

Here is an example of finding conflicting information about a product, and verifying what's going on under the hood. 

When deploying the Cisco 1532 series access points, you should determine what the power requirements are.   Let's start searching.

The first document can be found here:

http://www.cisco.com/c/en/us/td/docs/wireless/controller/technotes/7-6/b_1532_dg/b_1532_dg_chapter_01.html

The AP 1532 series is an ultra low-profile outdoor access point. This AP has two models, an internal antenna model and an external antenna model.

If you look closely, you will find that these access points are not the same AP with the exception of external and interal antennas.  The 2.4 GHz radios are different on the two access points.  The 1532i has a 3x3:3, and the other is a 2x2:2.  The 1532i  requires UPoE, while the other requires the lower wattage 802.3at power.  That makes sense - if there are more transmitters in the access point with internal antennas, it would require more power.  This might translate into needing different PoE switches (PoE+, UPoE) depending on which models you are deploying around your facility.

If you don't know what that means, no worries.  This graphic will better show you a 2x2:3 has two transmitters, and a 3x3:3 has three transmitters.

 

The number of transmitters relates to the number of available data rates.  More transmitters = more bandwidth.  For simplicity, we are going to say that 1x1 - 65Mbit/s, 2x2 = 130 Mbit/s, and 3x3 = 195 Mbit/s.

Our research so far states that the 1532i needs UPoE, and the 1532e needs PoE+, and the internal access point is capable of 195 Mbit/s, and the 1532e is capable of 130 Mbit/s.

Another document we found states that both access points can  be powered up using PoE+ switches, but the 1532i will power off one of the 2.4 GHz transmitters.  That might not make sense to someone not familiar with 802.11n.

 

http://www.cisco.com/c/en/us/products/collateral/wireless/aironet-1530-series/guide-c07-729725.pdf

Another way to say that would be, "when the Cisco 1532i is powered using PoE+, the access point will automatically turn off one of the 2.4GHz transmitters and the AP will be reduced to a 2x3:2 (130 Mbits/s) from a 3x3:3 (195 Mbit/s) capable access point, and the 5GHz radio is not affected).

One thing to note is the 1532e series access point is capable of 2x2:2 on the 2.4GHz radio.  Powering the 1532i with a PoE+ switch effectively makes both of the access points capable of the same data rates - though the 1532i still has three receivers and the 1532e has two.

After digging and deciphering the information ourselves, we stumble across another document that states the above facts more eloquently.

http://www.cisco.com/c/en/us/td/docs/wireless/access_point/1530/installation/guide/1530hig/1530_ch2.html#24750

If the 1532I is powered by a PoE+ (802.3at power) switch port or the AIR-PWRINJ-30= power injector, then the access point will automatically disable one of the 2.4 GHz transmitters and the radio will operate in 2x3 MIMO mode.

 

Now we have it figured out.  If the AP will meet our requirements as a 2x2:3 access point, then it is okay to use it on PoE+ switches.  It might be a good idea to know for sure, so we'll open up our protocol analyzer and double check.  We see the appropriate number of MCS rates per the  quantity of spatial streams per the document we found.

 

 

These "baseline" protocol captures might also come in handy in the future.  After an operating system upgrade, your roaming or some other functionality might seem to change behaviour, and it might come in handy to have a baseline capture of when your system was working well.

 

 

 

Converting your 5520 to a 5508 WLAN controller configuration

 

The goal of this document is to assist you (a Network Engineer that is comfortable navigating your WLAN Controller) in upgrading your WLAN controllers.  In this example, we will migrate from a 5508 WLAN controller to a 5520 WLAN controller.  The operating systems are different, and therefore the commands are as well.

There is an online tool that allows you to backup your existing configuration and run it through a migration tool which will give you the output you need to configure the replacement platform.

That tool can be found here: https://cway.cisco.com/tools/WirelessConfigConverter/

The tool will allow you to migrate wireless controllers to or from accross any of these platforms: 2500/5500/7500/8500/WISM2/3650/3850/4500 S8E/5760

In this example, we will need to upload the "show run-config commands" output or TFTP config backup from the 5508.  I'll use the TFTP option.  Start your TFTP server application on your desktop and browse to your WLAN Controller and instruct it to send a backup to your TFTP server.  You will have to use your IP address, not mine, and the naming convention that makes sense to you.  I use the IP address and date.

Your TFTP server should have received the file after a few minutes.  If not, check your firewall on your desktop.

 

Now browse to the URL mentioned above and the page below should load.  You'll need a CCO login to get to the tool.

Take the file that you received from your WLAN controller via the TFTP server and drag and drop it onto the center of the page where it reads, "Drop file here".

Now you need to look at the drop down above the "Run" button.  You need to select what you are converting from and what you are going to.  It is easy to miss, which is why I mention it.  Translation - I missed it.

Then click Run.  Your config should be below the Run button after you do it.  It might take a little bit of time, so don't panic.

Pay attention to the section that starts with, "Following configurations are encrypted on a 5508; 5520 can't understand them. Please consider reconfiguring them."  You will need those keys to bring your controller into production.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~END~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Following configurations are encrypted on a 5508; 5520 can't understand them. Please consider reconfiguring them.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~START~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

config radius auth add encrypt 4 10.15.20.2 1812 p <output snipped>