In a dense deployment, 40/80MHz channels are usually not a good thing. So I log into my controller and find there are TWO distinct places to disable it:
Wireless LAN > RF Management > 802.11[a,g] radio > Allowed bands for 40MHz channels
Wireless LAN > RF Management > 802.11[a,g] radio > 80MHz support
Wireless LAN > Virtual AP > SSID > High-throughput SSID > 40MHz channel usage
Wireless LAN > Virtual AP > SSID > High-throughput SSID > 80MHz channel usage (VHT)
Can I assume the intention here is to provide per-SSID advertisement of HT/VHT support (is that a thing?), or a per-radio (or per-band, as the case may be) knob that affects all SSIDs?
While we're here, I'd like to optimize AP roaming. Use case is highly mobile employees using laptops, tablets, phones, and WiFi enabled socks. Goal is to walk through a facility with some nearly 30 APs, and preferably not stay attached to the one AP mounted in the boiler room by the main entrance the entire time.
The IEEE has drafted an array of wonderful extensions that should make roaming a non-issue for any card developed since 2008. Naturally, WiFi card driver developers are doing everything they can to ensure that enabling these features results in zero connectivity for anyone. Understood.
However... use of a good portion of the 5GHz band is contingent on DFS, which as I understand, requires 802.11d and/or 802.11h to function. Nonetheless, we're still able to selectively enable this at:
Wireless LAN > RF Management > 802.11[a,g] radio > Advertise 802.11d and 802.11h Capabilities
I will assume that this switch is exactly what it says: ADVERTISE capabilities. I'm a little unclear whether it has any effect on the 5GHz band, since it kinda has to be there for DFS to work, right? I'll assume it's an option for 2.4GHz, and is only listed in the [g] radio config because ArubaOS doesn't distinguish between radio bands when attaching profiles. Is this reasonable?
Likewise, in the same page, we have "Enable CSA". I would really love to turn this on, because ARM is a bit twitchy at the location in question. Is this switch independent of the 802.11d/h avertisement? (I.e., can CSA be enabled with d/h advertisement disabled? Is that a good idea, a bad idea, or rather irrelevant?)