Problem with Internet Connection with WLC2504

[Jason Smith]

Hello all.  Suddenly we've experienced extremly slow internet connection speeds via our Cisco WLC2504 deployment.  From various speedtest sites latency is relatively low/normal (13-15Ms) but download and upload speeds only .9 - .8 Mbps respectively.  We have not had any changes on our network interfaces between AP's (AIR-LAP1142N-A-K9's) and various Cisco edge switches or our WLC.  Not sure where to get any clues on where this problem could have sprouted from.                 

[Victor Vasantha Kumar]

Hi Jason,

Please refer this doc to troubleshoot low throughput.

( http://www.cisco.com/en/US/tech/tk722/tk809/technologies_tech_note09186a0080b42507.shtml )

1) What is the datarate at which the client is associated ?

2) Get us "show client detail for the client that experiences low speed ?

3) Run an IPERF test and paste the details.

This information will be good to set a baseline for looking into the problem.

Thanks

Victor

[Jason Smith]

Below is a screenshot of the detail report of a test client with the internet:

                  

[Jason Smith]

Here is a iperf screenshot from the client to www.speedtest.net

[Victor Vasantha Kumar]

Hi Jason,

The client is connected at a datarate of 54 Mbps.

In a clean air environmentm, we can expect a max throughput of  around 20 Mbps in a production environment.

You may have to setup a local IPERF server and repeat the test.

This will get us the exact throughput.

PFA the doc to perform the Iperf tet.

https://supportforums.cisco.com/docs/DOC-39983

Thanks

Victor

[Jason Smith]

Screenshot of test from wireless client to iperf "server"

[Victor Vasantha Kumar]

Hi Jason,

Can you repeat the same test between two wireless clients on the same AP.

Also attach "show client detail   for both the clients.

Thanks

Victor

[Scott Fella]

Jason,

What is the speed internally on your network? What are the speed tests from a wired device. Have you looked at the switch to see if there are errors on the ports the WLC is connected to or the AP. Is the wired PC traceroute to the speediest the same as the wireless client?

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[Jason Smith]

Wired clients are performing perfectly almost 50Mbps down and up.  No errors on ports on switch between AP and subsequent switch port.  Same goes for ports connecting to WLC and Cisco 4506e.  All ports for APs and WLC are auto sense on speed and duplex, trunk with native vlans, specific vlans set, etc. etc.  Mind you all of this was working fine until sometime yesterday when clients started reporting poor internet speeds.  No changes were made port/speed/ wise.

[Scott Fella]

Well if nothing has changed, have you tried rebooting the WLC? Does this happen on all AP's? You have multiple WLC's?

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[Jason Smith]

Have already tried that and we only have one WLC for 25 production APs.  Also note the latency while running speedtest.net is fairly low but again internet speed is poor.

[Scott Fella]

So to be clear, internal speed is fine, internet speed isn't.

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[Jason Smith]

Correct, wired PC's are able to access the internet at normal speeds.  Wireless clients are not.

[Scott Fella]

Connect a wired PC on the same Vlan as the wireless client and test. Do you see a difference in throughout from the wired subnet and the wireless subnet?

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[Jason Smith]

Yes there is a difference.  Wired clients on the same vlan as those connected wirelessly via the wireless controller's interface mapping are connecting to the internet poorly.