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>

Tuesday, May 30, 2017

Cisco 1532i PoE+ vs. UPoE

 

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.

 

 

 

Saturday, April 1, 2017

FCC to reverse rules on Wi-Fi channel space

FCC to reverse rules on Wi-Fi channel space

 

 

How to use your Fluke spectrum analyzer with Ekahau ESS

How to use your Fluke AirMagnet Spectrum Adapter with Ekahau ESS!

 

We all know how expensive it is being a WLAN Engineer.  It costs upwards of 20k to get into this game, so we try to cut expenses whenever we can.  Here's a little known trick that will save you a few bucks.

 

As most of you know, Ekahau ESS will open up your AirMagnet Site Survey files.  But did you know you can also use your Fluke spectrum adapter with your Ekahau ESS?

 

You'll need to download the latest version of ESS, which is version 8.8.0, which was released today.

After you downloaded it, check to see the file looks like this:

 

Install the software - but with this little trick.  You have to hold down the "Airplane Mode" button during the installation of the software.  This tricks the software into bypassing some of the drivers for the AirMagnet adapter, which you will NOT need to install.  In fact, uninstall the drivers on the machine if they are there.

After the installation, plug in the Proxim adapter and Fluke adapter as usual.  Your setup should look just like this: (note, you can only use one Proxim adapter with the Fluke adapter)

 

 

Next, configure the Fluke adapter just like you would the Metageek WiSpy DBx adapter.  In fact, you cannot tell the difference in ESS.  The Fluke adapter only works for 5GHz, though.  That should not matter, since 2.4 GHz is dead! 

 

 

Now  you can begin using your spectrum analyzer!

 

 

This little trick works the same way if you have the older PCMCIA card as well and a laptop with the slot.  Most of us don't have those machines anymore, but if you did, it would be the same installation.

 

I hope this little trick helps you save a few bucks this April Fool’s Day.

Enjoy.