Wifi is very slow sometimes

[wfqk]

Hi in our production environment, users in one area feel wifi slowness sometime. when we got to the user site, they did not feel slowness because the slowness does not happen all the time. we did not find something wrong. we need to check later when it happen again. 

we know a lot reasons can cause the issue. My question is do we have general way to check and find the reason step by step? and what is most common reason that cause the issue? Thank you

[Flavio Miranda · Accepted solution]

Hi

 There are some questions that might help:

 Slowness accessing what? 

 Not necessarily slowness is wifi fault. A busy web server for example can cause bad user experience on the wifi network although the problem is not on the wifi network per se.

 Bad DNS service, DHCP service, firewall or other security system also can cause slowness on the user access.

 But considering you have eliminate all this possibility and wifi is actually the ofender, then you can start by looking the air time utilization.

 2.4 GHz band usually works with very high channel utilization and consequently will offer bad performance.

 If the slowness is observed on peak hours, certainly channel utilization is your problem.

 Try to use 5.0 GHz don't matter what.

-If I helped you somehow, please, rate it as useful.-

[wfqk]

Thank you so much for your reply. it is very good answer. I am going to get detail when it happen again. 

BTW, we are using WLC5508, can you suggest how to transfer 2.4 GHz band to 5.0 GHz?

[fdharmawan]

Hi,

As far as I know, in the end it would be the APs who perform 2.4GHz or 5Ghz.

Do you know your AP type? If yes, then look for the datasheet.

[Scott Fella]

Don’t assume but try to eliminate variables one at a time. Basic things is gather information and determine if the issue is when access an application, web or that they loose connection. Then determine if the issue is with a certain device, device model, NIC and or driver.

When folks like us try to provide a solution that would help, we also assume that the configuration and design is proper, that your running a stable code and that you have adequate coverage along with AP density. 

There are a lot of variables that can cause user experience issues so also don’t just think it’s wireless as it also might be an issue with your Infrastructure. 

[Flavio Miranda]

Play with power first. On the TPC or Wireless allow 5.0 GHz network from -10 up to 30 dBm André on the 2.4ghz change this range from -10 up to 17 dBm.If you have RF profile then you can change there.

 After playing with power, enable Band Select. 

 This might be enough. Recently I changed the percentage from 50% to 90% with this approach.

-If I helped you somehow, please, rate it as useful.-