channel change interval

[syedimteyazahmad]

Hi All,

Need help

Users facing regular slowness and sometimes disconnection during peak office hours. We have enabled 80 MHz channel with Channel change interval of 10 minutes. Is it might cause issue. Its new deployment and facing on site where user use more wi-fi

If not what can be issue

[patoberli]

Depending on the density of your network and neighbor Wi-Fi, you actually have a lower throughput with 80 MHz channels compared to 40 MHz. 80 MHz is also more interference-prone than 40 MHz.
I also recommend to set the channel change (DCA) to 2-6 hours while leaving RRM on low or middle.

[syedimteyazahmad]

Hi @patoberli 

Need clarity on feedback provided.

80 Mhz more interfrence prone means we have bonding of 4 channels which result in less availability of channels for other nearby APs. Is my understanding correct?

As per cisco documentation 80 Mhz more throughput compared to 40 Mhz. Refrence document below 

https://www.cisco.com/c/en/us/td/docs/wireless/controller/technotes/8-6/b_Cisco_Wireless_LAN_Controller_Configuration_Best_Practices.html

Are you saying throughput issue on the basis of end client not supported 802.11ac or something different . Please help

[Haydn Andrews]

Whilst the 80MHz wide channels will have more throughput, using them reduces the number of non overlapping channels available.

Currently I would only recommend using 80MHz wide where you are in a quite RF area.

[patoberli]

The total bandwidth with a single AP does indeed nearly double with an 80 MHz channel compared to a 40 one. But that is only true if there are no other APs in the area, affecting the 4x 20 MHz wide channel. It only takes one disturber in that 80 MHz range to kill (make worse) the whole 80 MHz. That risk simply is smaller with 40 MHz. With 40 MHz you also have a higher throughput at longer reaches (most of the time).
A site survey would show you the optimal channel plan.