topic Hello Terpstra,Thank you very in Wireless

How to deal with heavy users - lots of downloads

fabiogarcia — Mon, 05 Jul 2021 09:44:30 GMT

Dears,

Our Wireless environment faces a lot of co-channels and sometimes also 3 or 4 overlappings. Unfortunately we cannot change to 5GHZ range because of our laptops.

Sometimes when we do some downloads, we see a lot of packet drops on all clients connected to the same AP.... We use WLC 5508 and APs 1142, 2602i, 2602e and 3602e APs.

Is there any feature on WLC to deal with these downloads ?

thanks!

Did a site survey take place

Freerk Terpstra — Wed, 18 Mar 2015 21:25:08 GMT

Did a site survey take place when the network was being installed? If so, you can use that as a base line and input for making changes to your network and validating those. If not I would advise you to do so, so you really get to know your RF and determine if the problems you are running into can be fixed with configuration changes only or if you physical need to make changes (like changing the position of AP's or swapping antennas).

In the mean time I would advise you to check the current AP power-levels of the 802.11b/g/n radios and also the data-rates you have currently enabled for 802.11b/g/n. If you don't have any 802.11b and/or 802.11g only devices I would disable all the data-rates under 12Mbit/s and make 12Mbit/s the only mandatory data-rate. This should at least limit the effects of CCI a little, but you really need to watch the power-levels and also monitor the WLC logging of coverage errors.

Depending on the current version of code you are running, also a software upgrade may fix some issues you are probably running into. Version 7.6.130 or 8.0.110 are good choices at the moment.

Hello Terpstra,Thank you very

fabiogarcia — Thu, 19 Mar 2015 13:59:37 GMT

Hello Terpstra,

Thank you very much for the reply... We didn't do a survey... Our network simply had a fast growth... We used to have 3 APs in my floor and we bought 3 more because of the number of people being hired... But it looks like the number of co-channels and overlapping is the problem right now....

Unfortunately 80% of our laptops use 802.11g, so we cant avoid 2.4Ghz range....

All parameters concerning channel and power level are the default ones... Controller is handling that... But thats strange because sometimes we see at INSSIDER that channel 6 for example would be the best channel for certain AP but controller keep it at 1.... also, my managers are complaining how a such expensive device cannot handle traffic avoiding heavy users to consume all bandwidth...

I think the only way would be a static bandwidth configuration at WLAN tab right ?

again thanks for your help!!

Please refer to the link for

Abhishek Abhishek — Fri, 20 Mar 2015 01:12:17 GMT

Please refer to the link for best practices of WLC configuration-

http://www.cisco.com/c/en/us/td/docs/wireless/technology/wlc/82463-wlc-config-best-practice.html

The default settings are not

Freerk Terpstra — Fri, 20 Mar 2015 20:56:05 GMT

The default settings are not great, and that is a understatement 🙂

Some copy and past from my previous post; "If you don't have any 802.11b and/or 802.11g only devices I would disable all the data-rates under 12Mbit/s and make 12Mbit/s the only mandatory data-rate."

So go to wireless -> 802.11b/g/n -> network and disable it so you can change your data-rates. Set all data rates from 1Mbps until 11Mbps to "Disabled", make 12Mbps "mandatory" and all the others "supported". Now you can enable the radios again.

In the mean time please contact somebody who can perform a site survey.

Hello my friend! Thank you

fabiogarcia — Mon, 23 Mar 2015 19:16:51 GMT

Hello my friend!

Thank you very much for your help!!

I did that... We are monitoring and no issues till now... What exactly is the point doing that config ? Decrease the number of beacons and control packets from APs?

Again thanks for your help!!!

Those changes do two things

Freerk Terpstra — Tue, 24 Mar 2015 19:12:35 GMT

Those changes do two things basically.

When you disable the lower data-rates, you decrease the cell size of the access-points. The cell size gets smaller because with lower data-rates enabled, the modulation is simpler so clients can still decode this information with a weaker signal. Because of disabling those lower data-rates there is also a chance that clients will roam better, but the biggest win with this change is less co-channel interference.

The other thing is that the mandatory data-rate is now much higher. Because of this management frames like beacons are being send at a higher speed so the channel will be faster free for other clients to send traffic. Multicast network traffic is being send on the highest available mandatory data-rate as well.

Last, but not least, I would like to recommend you doing a site survey to validate if you get everything out of your deployment.

If your problem has been resolved please mark this topic as answered, feel free to give points for helpful responses.