In this post we will look at how to control per user bandwidth in wireless environment. This is based on 220.127.116.11 WLC code (which is in CCIEW v2.0 lab) & in later software codes Cisco has enhanced this feature.
Here is the test setup where a wireless client (Laptop) is on a WLAN (named WGB-CAPWAP) & a PC attached to a switch. We will test the bandwidth usage of wireless client by copying a file between these two hosts.
Here is the QoS profile configuration settings for Silver where my WLAN is configured for(by default all wlan created associate with QoS profile silver).As you can see per user bandwidth you can set in kbps. “Average Data Rate” & “Burst Data Rate” apply for TCP traffic & corresponds to avg & peak value. “Average Real-Time Rate” & “Burst Real-Time Rate” is refer to UDP traffic.
Here is how I applied this profile onto my “WGB-CAPWAP” wlan.(by the way this is default configuration & you can change this as needed)
First we will check the wireless user bandwidth usage with this setting. Here is the wireless client bandwidth usage when file copy from Laptop to PC (in other words upstream traffic from wireless client). As you can see it is around 54Mbps (144Mbps*37%)
Then I copy the file from PC to Laptop which is reflecting downstream traffic of wireless client. Again it is around ~50 Mbps mark (144 Mbps *36%)
Now we have a baseline to test. So will change the QoS profile settings to limit user traffic to 20Mbps. I have given Burst Data Rate 21 Mpbs (Peak value always should be greater than Average value). Also note that my traffic is TCP (file transfer), So I have only set those specific settings.
Now let’s do the test again. Here is the same file transfer from Laptop to PC (Wireless Upstream traffic). As you see here it is almost same bandwidth consumption around ~54 Mbps. No effect of our restrictions.
Let’s see the other way around from PC to Laptop (Wireless downstream). Here we go… you can bandwidth is restricted to ~ 20 Mbps (144 Mbps *15%) and our configuration is works. But only downstream direction.
This is the behavior of software code 7.0.x & in will only limit the per user bandwidth only downstream direction. Again no option to apply this to selected WLAN and applicable for all WLAN configured with QoS profile.
I think there is some wrong information in WLC 18.104.22.168 configuration guide (page 4-65 to page 4-68) where the screen captures shown are not from 22.214.171.124 code. Max RF-Usage per AP & Queue depth is not available to configure in 126.96.36.199 ( I think these captures were taken from previous codes). So be careful when reading those config guides as there may be some wrong info 😯
Since 7.2 onwards Cisco introduced upstream & downstream user bandwidth restrictions & you can apply this on per WLAN as well. Here is the configuration page looks like in a later code (this is from 188.8.131.52)
You can read following Cisco deployment guide to understand how this configure on these latest codes.
Bi Directional Rate Limit – Deployment Guide (Doc ID 113682)