Cisco doc says,
Channels 116, 120, 124, and 128 are not available in the U.S. and Canada for 40-MHz channel bonding.
However I can assign them on a 3800 AP. NOTE: I can not on my "n" AP's so does this apply to "n" AP's only and document just needs an update?
Also RRM does choose 116/120 and 140/144 on 3700's so the statement in the document is confusing. Can anyone especially Cisco verify what does that statement mean?
That will depend entirely on the Regulatory Domain of the AP and the controller.
If the WLC has the country code of US &/or CA, then you can enable the above channels, HOWEVER, the associated APs won't use those four channels.
But that is not the important bit. The most important part of a wireless network is the "least common denominator". Your wireless network & wireless design must ensure the worst performing wireless client will or must be able to authenticate to the wireless network.
For instance, UNII-1, UNII-2 and UNII-3 are enabled but the worst performing wireless client is one that only talks in UNII-1. So when this client roams to an area where APs are broadcasting in UNII-2 &/or UNII-3, this wireless client will drop.
I understand the client limitations and using only channels that are supported by the clients. Already know that part and have verified all that using pcaps and vendor tech specs. Back to the main question. I still need to know why Cisco document says that WLC will not use those channels in US and Canada. Because that statement is not true.
1- Cisco 2602 is 802.11n and I was not able to assign 116 or 140 manually with 40MHz width. Makes sense on 140 as 40MHz because 144 was allowed when ac came out
2- Cisco 3800 which is ac wave 2, allows manual configuration of both 116/120 and 140/144 at 40MHz.
3- Cisco’s statement in that doc states that WLC will not use those channels however I have seen RRM utilize those channels especially on IW3700s so technically that statement is wrong and/or doesn’t make sense because those channels do get assigned.
So is it possible that the document needs updating ? Hope this makes more sense. It’s critical to verify this statement from Cisco due to multiple reasons hence I’m trying to find something solid on that.