5508 fast ipferf tests but slow internet speeds

[Haas11116]

Hello,

A little device info for you first on what we have.

Cisco 5508 with 16 AP's. Current code is: 8.2.100.0. Encryption is WPA2 + AES. The AP models are AIR-CAP3502I-A-K9. Our internet provider speeds are 100 MB.

We have a Cisco 5508 at our main site with 16 AP's scattered about in various offices. Users inside the main site and remote sites complain of slow internet speeds. This is true with Android, IOS, and Laptops. What's odd is my speed tests from Century Link and Speed Test show download speeds of 10-13 MBs and upload speeds of 65-70 MBs. I can validate no one is hogging the network. After troubleshooting the issue, we ended up calling Cisco support. Cisco support made a few tweaks with data rates (Mandatory, Supported, Disabled) and a few other small adjustments, but no relief on the internet speeds. What's odd is we also performed some iperf tests on the WLAN.

I setup my desktop as the wired client server, and a laptop as the wireless client. The speeds iperf was reporting was 75-80 MBs. The same is true when I reverse the test to make the wireless client the iperf test server and the wired PC the client. We ran several tests. However, when we do a speed test from a wireless device to the internet we only get 10-13 MBs. One of our guys opened a port on the VLAN the wireless AP's were sitting, plugged his laptop in and ran a speed test. The speed tests came back at 75-80 MBs wired in. The odd thing is all wireless devices we used to do a speed test had a huge upload speed of around 65-70 MBs. I would buy the argument of the AP's working half-duplex and being slower if the upload speeds would be low as well. However, every test shows the upload speeds from wireless clients are 65-70 MBs. I also setup a new AP and plugged it directly into the switch to use as testing. I get the same results. We do not have any overlapping channels, and we do not have any interference failures. Cisco told us (Not a problem with the WLAN, iperf proves it) and left us to figure out why getting to the internet is so slow. So to summarize, our wireless clients at all sites have slow internet access. By the way, no one is getting kicked off.

[Leo Laohoo]

Have a read of THIS.  Not all wireless clients are created "equal".  The box and/or brochure might say a smartphone is 802.11ac wave 2 "ready" but in reality is, with only ONE (1) radio it is hard for a wireless client to push past 100 Mbps in a lot of cases.  For smartphone & tablets, check how many spatial streams each model supports.  This will help determine what is the maximum speed each wireless client model can/can't support in throughput. 

For claims of "slow", kindly determine this: 

1.  When wireless clients are reporting slow, what is the result when they go to speedtest.net?

2.  Are the wireless client connected to 802.11a or 802.11b radio?

3.  What is the result with the command "sh client detail <wireless client MAC address>"?

However, when we do a speed test from a wireless device to the internet we only get 10-13 MBs.

Hmmm ... Internal speed test is fine but external speed test ain't?  Please check the link between the WAN inside interface and the core switch interface ain't getting congested and/or line errors.

[Haas11116]

Sorry for the delay, listed below is some information you requested.

Speed Tests:

Internet Speed Tests Wired Century Link
73.31 Mbs Download 90.89 Mbs Upload

Internet Speed Tests Wired OOKLA
71.83 Mbs Download 85.39 Mbs Upload

Internet Speed Tests Wireless DELL Laptop Century Link
18.10 Mbs Download 45.99 Mbs Upload

Internet Speed Tests Wireless DELL Laptop OOKLA
20.50 Mbs Download 35.11 Mbs Upload

Internet Speed Tests Wireless iPhone 6+ OOKLA
13.97 Mbs Download 19.10 Mbs Upload

Internet Speed Tests Wireless iPhone 6+ (Speed Test App)
15 Mbs Download 21.25 Mbs upload

IPERF3 Tests:

IPerf3 test from wired to wireless
40 MBytes 50 MBytes

IPerf test from wireless to wired
35 MBytes 50 MBytes

The clients I am testing are attached to 802.11a. I waited till after hours, rebooted the switch and the 5508. All ports are connected at 1GB.

There is a ton of information when I run the sh client command. Anything particular you are looking for so I can reduce the amount of info to copy? Also what is odd is since the reboot, I don't get the high upload speeds as I had in my original post.

[Leo Laohoo]

There is a ton of information when I run the sh client command. Anything particular you are looking for so I can reduce the amount of info to copy?

Put the output of the command "sh client detail <wireless client MAC address>" into a text document and then attach to the thread.  I want to see it all.  

Check for Layer 1 line errors from the AP all the way to the router.

[Haas11116]

Attached are two uploads as requested for "sh client detail <wireless client MAC address>" .

one is from an iPhone the other a desktop. The passwords and group info in the test were replaced with the word "Secret".

[Leo Laohoo]

Everything looks fine.  Good data rates, good RSSI, good SNR.  

Remote into the AP "WAP_IT" and post the output to the command "sh interface G0".  Look at the output to the command "sh cdp n" of the AP and remote into the switch connected to the AP.  Post the output to the command "sh interface <PORT>".

[Haas11116]

The AP output is attached. I also ordered a newer model AP for testing:

AIR-AP3702I-UXK9

[Leo Laohoo]

The AP Gi 0 input & output counters are very low, like the AP has just been recently reloaded.  

I am not convinced this is a wireless issue and leaning towards either a QoS issue or a bottleneck upstream.  

[Haas11116]

Yes it was actually. I inherited this system and had to reset it's password. I'll wait a day before getting new stats.

[Haas11116]

Attached is a new upload from the WAP.

[cedric_marodon]

WMM is not enabled for both clients. WMM may be useful in the WLAN settings to enable the 802.11n/ac data rates. Try to set WMM to Required or Optional in the WLAN configuration.

In the show command results, the clients are using 54Mbps data rate. 10-12Mbps is an average throughput for such a data rate in a multiple client shared environment. You can increase the throughput by increase the Channel Width from 20MHz to 40MHz or 80MHz (802.11ac) depending on your client capability.

What is your type of application that would be slow with 10-12Mbps?

[Hai Cheng Xu]

i think it is client's negotiation issue，you can turn off tkip only enable aes in WLC.

[steve255.0]

TKIP I believe no one turn on.

[Haas11116]

TKIP is not enabled. Only AES.

[steve255.0]

I have this same issue, iperf speed ~400mbps, but internet speed only 65mbps. Is there any update?