Wireless Access

Anyone know this value?  ARM profiles can be dropped to 3 dBm, which I have tried, but no APs are below 5, (and most are at 5).  I have a school district that another VAR deployed an 802.11ac wireless deployment.  The walls are very thin.  I have already dropped BC/MC, disabled TX rates <18 db in SSID Profile, set ARM to Min 3, Max 12, and most of the other recommendations in the VRD.

Still, most APs are at 5 dBm on Radio 1.  This has me wondering if the AP-215 will go below 5 dBm Min TX.

BTW I have an open TAC case due to code 6.4.2.12 not having ARM lower TX powers.  Despite configuring lower EIRP values in ARM, the APs still broadcast at their maximum 23 dBm.

Trying to improve roaming and client connectivity.  This is a typical school district 1 AP per classroom deployment.  A "Show AP Active | Inc Filter" revealed that a high percentage of APs are broadcasting at the minimum configured ARM TX EIRP of 6 dBm.  I lowered this to 3 dBm, and most APs dropped to 5 dBm (NOT 3).  This has me wondering if the AP-215 can actually go lower than 5 dBm TX power?

Hm interesting. I don't think I've tried to go that low. Hopefully someone else has some insight. Do you have a TAC case open on this issue as well?

Wifi_Willie,

Choose an AP and type "show ap debug driver-log ap-name <name of ap>".  I believe the internal antenna gain is 5db for the AP 215 so that is the lowest you can set it.  Are you having problems on the 2.4ghz or the 5ghz band?  If it is on the 5ghz band, just make sure you are using 20mhz channels and you could have enough non-overlapping channels to make it work.  If it is on the 2.4ghz band, you might want to consider ARM mode-aware for the ARM profile on the 2.4ghz band....

That is right, I just checked.  The internal is 5 db on the 215.  That is the floor.  Mode Aware is enabled.

Okay.  If the customer has Airwave, make sure Amon is configured so that you can track the RF utilization on those access points at midnight and at peak before and after you make your changes.  At midnight the RF utilization on either band should be no more than 1 to 5%, otherwise you probably still have too much coverage.   Also make sure you have client-aware off so that the APs are free to move to better channels throughout the day, at least after you first make your changes.

The next step may be disabling the 2.4 gHz radios on some APs.  I am assuming the best way to do this is to have a print of the floor plan, list out all the APs, and begin to manually assign channels on paper to create a channel map, which will reveal logical breaks at which point to disable radios.

No Airwave.  :(

Okay.  Typing "show ap radio-summary" will get you the current RF utilization for all access points, just like the dashboard, so you can observe where you have the highest utilization at the time.

Neat command.  I like that!

The utlization values on some are above 50%.  I know school hasn't started yet.  I am assuming this is one of the values that is used to calculate the "Channel Busy" in the Dashboard?

Yes.  Make sure you are using 20 mhz channels instead of 40 or even worse 80mhz channels on the 5ghz.

(allowed bands for 40 mhz should be none, and 80 mhz support should be unchecked in the ARM profile)

Make sure you have separate Radio and ARM profiles for both the g and the a bands so you can change them independently (the Radio Profile is Tied to the ARM profile, so you need to create a radio profile, then an ARM profile for both bands, and then apply them). 

Change the Max TX power on the g band to 9 and the min-TX to 6 and then observe the utilization after 5 minutes

Change the Max TX power on the a band to 18 and the min to 12 and then observe the utilization after 5 minutes.

You might want to have ARM mode aware Off first on the 2.4ghz band when you are changing the power, because that would be changing too many things at one time.  ARM mode aware should be considered a last resore, because it is indiscriminate.  Try lowering the power on the 2.4ghz first and check the utilization.

When it is really busy, the RF utilization can rise to 50 percent and there is nothing you can do about it, but you can first make sure when classes are empty, it is not already up there, so that you can give clients room to operate when things spike.