Wireless Access

Does anyone have any background info on the settings for band steering in the ARM profiles, specifically "Band Steer G Band Max Signal" and "Band Steer A Band Min Signal"?  

We have a number of AppleTVs and other Apple devices in a relatively dense environment and band steering events are happening with enough frequency for people to start complaining their mirroring sessions are being disconnected regularly.  We have turned down transmitting power which has helped, but we're still seeing problems.  Our ultimate goal is to shut off 2.5 ghz, but I don't have enough APs deployed to do that yet.

My goal right now is to make the controller a little less aggressive when it comes to steering clients from 2.5 to 5 ghz and still keep all the other benefits of ARM.

Mike

What version of ArubaOs are you running?

There are two sides to this equation:

- Is the client being steered?

- is the AppleTV being steered?

-  How do you determine either?

You determine either by typing:

show ap arm client-match history client-mac <mac address of device>

 That will tell you if client match activity was even ocurring at the time of the issue.  If it is not, you could have a genuine RF, client or application issue.  I would determine that before tuning clientmatch settings that apply to all of your clients.

I'm running 6.4.2.0.  It's mostly the clients that are being steered, although occasionally the AppleTVs.  We've matched the band steering event lists for each client in Airwave to the approximate times many users have reported problems.

Mike

So,

This could be a complicated issue.  If you make the AppleTV wired and turn off clientmatch, it would rule out those possible issues entirely so tha you can determine if you have any other issues. I say turn off clientmatch with a great deal of reservation, because it is a huge advantage of deployed properly.  The 2 reasons why clientmatch would not work properly with the defaults is if (1) Access Points are spaced too far or too close together (2) The power on your access points are too low or high.

While the the AppleTV mirroring being disrupted is the most common symptom, I've seen a number of other problems with Mac clients (particularly recent model Macbook Pros) where the band steer will occur, but the laptop will refuse to change, resulting in a dead connection and requiring the user to cycle wifi off and on.

I fully agree that Client Match is a great technology and I want to keep it running for all of the benefits it offers.  As you pointed out, the issue is ultimately related to the signal strength of each AP.  We've experimented with different power settings, but our buildings (newer schools with lots of steel and concrete) are great at destroying signal quality.  Compounding the problem, we have buildings that have both dense and sparse coverage, resulting in a lot of AP specific configs.  Generally speaking, things work pretty well, but band steering seems to be causing me the most problems at the moment.

Mike_Graham,

I am not sure that I can advise you properly on that.  You probably need someone who is willing to look at your whole infrastructure and determine what you should be doing.  I have never heard of a client having to disable then re-enable their wireless card after a steer.  You could have other issues going on.

You say you are using ap-specific profiles...  why?

At our high school, there are some regions of the building that had to be densely covered.  These regions of the building were not as degrading on signal strength as some less densely populated areas so we ended up turning down these radios to almost microcell levels to reduce interference. 

Okay.

Maybe you should focus on a single region first so that we are not dealing with a whole bunch of variables.  Do you have airwave?