About Cisco DCA

[Julian Ortiz]

Hi community,

One question about Cisco DCA. DCA continuously evaluates the channel assignments on a per AP per radio basis and dynamically adjusts the channel plan to maintain performance of individual radios, but changing the channel of an AP is potentially disruptive:

https://www.cisco.com/c/en/us/td/docs/wireless/controller/technotes/8-3/b_RRM_White_Paper/b_RRM_White_Paper_chapter_0100.html

With this in mind, and taking into account that RF conditions change continuously, and therefore DCA can change channels many times during the day, isn't it a good idea to set the DCA operation mode always to "Scheduled DCA" in order to have the channel changes only during off peak hours?

I know that DCA algorithm will only run at the scheduled time and will not evaluate the users environment at peak loads, where the RF conditions could be significantly different, but to get the clients disconnected due to DCA channel changes is even worse. What do you mean? Anyone with hands-on on this?

Regards,

Julián

[pieterh · Accepted solution]

"but changing the channel of an AP is potentially disruptive"

Yes, but this does not happen out of the blue,

this will be triggered by events like interference, RF-channel utilization, Radar signal detection etc.

These triggers are potentially dangerous for Wi-Fi performance too.

most client will just re-associate and go on with what they are doing, just as if they switched to another AP.

only response critical applications will notice the disconnect.

If you do the adjustment out of "peak-hours" the decision for channel assignment will NOT be optimized for peak hours!

you have to weight the DCA disruption against the reason WHY  RRM/DCA decides to change channels.

only in heavily changing environments this will happen multiple times during the day.

You have some influence on the mechanism by adjusting RRM parameters.

[Julian Ortiz]

Hi pieterh,

Thank you very much for your reply and clarification, that was exactly my doubt.

Regards,

Julián