WLC 802.11a Global Parameters to achieve AC

[bhupenderrawat79]

Hello,

What would be data rates to only support 80211ac or to allow the max speed possible on the wlc.? Thanks

[RichardAtkin]

Hah - I just tried doing this (disabling all but 11AC) on a WLC, and you can't... though you can get close.

Go here in the WLC GUI;   Wireless > 802.11a/N/AC > Network

Disable the 802.11a network

Disable all of the rates, apart from 54Mbps which must be Mandatory (seems you cant have them all off)

Go here in the WLC GUI;  Wireless > 802.11a/N/AC > High Throughput (11N/11AC)

Disable all of the n (MCS) rates (don't just un-tick "11n mode" as this seems to turn off 11ac too)

Ensure all of the ac (VHT MCS) rates are enabled and that 11ac mode is enabled

Go here in the WLC GUI; Wireless > 802.11a/N/AC > RRM > DCA

Enable a wider channel width.  If you're just doing this as a test in a lab with no other WiFi around to see what speeds you can get, select 160MHz channels.  If you're doing this in the real world and you have several APs, limit yourself to 40MHz.

Go here in the WLC GUI;   Wireless > 802.11a/N/AC > Network

Enable the 802.11a network

This should leave you with only 54Mbps (802.11a) and all of the 802.11ac rates enabled.

--

Edit to add:  Obviously doing this will mean that anybody with an older Client (say, one that can't do AC) might struggle to even connect, but it's the answer to your question.  In the real world, most people would disable all but the slowest A rates, leave the all of the N/AC rates enabled, and just do the 40MHz DCA setting, to get a good balance of performance and support for various clients.

-- Another edit:  Actually, before you do any of that, I suppose I should ask "What is it you actually want to achieve and why?"

[Sandeep Choudhary]

Hi,

Here are the 802.11ac data rates:

https://community.cisco.com/t5/wireless-mobility-documents/802-11ac-mcs-rates/ta-p/3155920

Configuration req:

802.11ac (like 11n) requires the WLAN to have AES encryption (or Open) and WMM. Also, 4 channels must be available and assigned to each AP for the 80MHz bond to achieve highest rates.  If using the WLC, check under DCA and verify 80MHz channel width is enabled.  If any one of these is not met then 11ac will not work.  Too, check the driver configuration of the client adapter and verify it’s set properly for 11ac.

More info here:

https://community.cisco.com/t5/wireless-security-and-network/ask-the-expert-wireless-802-11ac-configuration-and-client/td-p/2478150

Regards

Dont forget to rate helpful posts

[RichardAtkin]

The latest APs are doing 160MHz channels now, so you need 8 channels if you want the highest rates.

[patoberli]

802.11a data rates are required for the client to actually see the SSID, as those Beacons are sent on the lowest (or was it highest) Mandatory 802.11a (or g) datarate, even for 802.11n/ac clients. If the client can't read the beacon sent with 54 Mbps and answer it (in your case), because the signal is too weak, it can't associate with the SSID.
That's why it's recommended to have 24 - 54 enabled, with a tad lower AP density even 18 Mbps enabled.
See the high density tuning guide for more information:
https://www.cisco.com/c/en/us/products/collateral/wireless/aironet-1250-series/design_guide_c07-693245.html