topic WLC 5508 WiFi slow speed in Wireless

WLC 5508 WiFi slow speed

RickTan1981 — Mon, 05 Jul 2021 13:17:06 GMT

Hi all experts,

Our company WiFi using Cisco WLC 5508 (Version 7.2.103.0) with 10 Cisco Aironet 1130AG AP(Air-AP1131AG-C-K9).

All function works normal but WiFi client just got 3 Mbps network speed (400 kbps during copy file) even though the WiFi connection show 54 Mbps.

Cisco WLC 5508 connected with Cisco 3750 router port channel (1000 M port *2).

1131 AP connected with Linksys switch 100 M port.

No Qos settings on Cisco 3750 router and Linksys switch.

Cisco WLC 5508 setup 5 Wlan SSID with different Vlan. All Vlan QoS is set to Silver(best effort) and WMM policy is allowed. Silver profile is no Per-User bandwidth settings. (all vlan is 0)

How to troubleshooting this issue or can you give some advice? Thanks in advance.

1. Are the wireless clients

Leo Laohoo — Thu, 29 Dec 2016 10:44:41 GMT

1. Are the wireless clients connected to the 802.11a or 802.11b radio?

2. Does this happen all throughout the day or during business hours? Does this issue happen during the weekend?

Hi Leo,

RickTan1981 — Fri, 30 Dec 2016 02:01:20 GMT

Hi Leo,

1. All wireless clients connected to 802.11g which show in clients status.

2. I thought the issue happened all day. I have special SSID & AP which just could be connected by my test client. When my test client connected the SSID, the speed also just 3 Mbps during copy file or test speedtest website.

1. All wireless clients

Leo Laohoo — Fri, 30 Dec 2016 05:14:26 GMT

1. All wireless clients connected to 802.11g which show in clients status.

Ok, so ALL the wireless clients are connected to the 802.11b radio. Which means that the issue could, potentially, be co-channel interference.

Since 1131 do NOT support CleanAir, what happens if the wireless clients are forced to the 802.11a radio?

Another thing to look at is/are the line errors between the APs and the switch. See if there are any line errors, speed/duplex mismatch errors.

Hi Leo,

RickTan1981 — Fri, 30 Dec 2016 10:50:08 GMT

Hi Leo,

1. Yes. All clients connect 802.11b radio. I already disable Date Rate below 11 Mbps.

2. Our laptop just support 802.b/g, cannot force to 802.11a. I disabled 802.11a with no effect.

3.I considered the issue may cause by cable or switch. But no error syslog from switch so far and weird thing is that the traffic threshold keep 3 Mbps on both downstream and upstream.

2. Our laptop just support

Leo Laohoo — Fri, 30 Dec 2016 10:59:02 GMT

2. Our laptop just support 802.b/g,

What is the exact model of the NIC card? There's a big chance the NIC card can only support <75 Mbps.

Just curious... what is the

Scott Fella — Fri, 30 Dec 2016 11:44:07 GMT

Just curious... what is the speed if you had a wired laptop connected to the Linksys switch the AP's are connected to?

-Scott

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Hi all,

RickTan1981 — Tue, 03 Jan 2017 03:47:35 GMT

Hi all,

It's normal when laptop connected wired cable (100M) or other buffalo wireless route (40M).

Laptop WiFi card is Dell DW1501 wireless-N WLAN Half-Mini card.

Laptop WiFi card is Dell

Leo Laohoo — Tue, 03 Jan 2017 04:46:15 GMT

Laptop WiFi card is Dell DW1501 wireless-N WLAN Half-Mini card.

Ok, just as suspected. Dell 1501 only has ONE (1) radio only supports 2.4 Ghz.

The "fastest" speed one can get with this card is <72 Mbps.

So the issue is more likely to be co-channel interference.

Hi Leo,

RickTan1981 — Tue, 03 Jan 2017 06:42:42 GMT

Hi Leo,

So the NIC cause the "co-channel interference"? Any way to fix this issue?

I try to configure AP Mode from local to FlexConnect (H-REAP). But it still has the same issue. In Web UI, it show traffic both in 802.11G & 802.11A. In CML, the traffic just show in 802.11G.

So the NIC cause the "co

Leo Laohoo — Tue, 03 Jan 2017 07:38:26 GMT

So the NIC cause the "co-channel interference"?

Co-Channel Interference comes from various sources:

1. Strong WiFi from neighboring APs;

2. Bluetooth;

3. Microwave ovens; etc.

Any way to fix this issue?

Normally, if we suspect co-channel interference we recommend using 802.11a. Since all the laptops are 802.11b-only then they will have to bear it or upgrade the laptops' NIC for dual band (like Dell DW1520).

Hi Leo,

RickTan1981 — Wed, 04 Jan 2017 03:44:29 GMT

Hi Leo,

I found one laptop support 5G 802.11a, NIC type intel centrino advanced-N 6200 AGN. Test speed is 6M (720 kbps).

I found one laptop support 5G

Leo Laohoo — Wed, 04 Jan 2017 04:27:07 GMT

I found one laptop support 5G 802.11a, NIC type intel centrino advanced-N 6200 AGN. Test speed is 6M (720 kbps).

1. On the controller, post the complete output to the command "sh client detail <Intel 6200 MAC address>".

2. Remote into each AP and post the complete output to the command "sh interface F0".

Hi Leo,

RickTan1981 — Wed, 04 Jan 2017 05:21:50 GMT

Hi Leo,

Attachments are the putty logs. AP1 is the laptop (5G) connected.

Thanks.

Current Rate.................

Leo Laohoo — Wed, 04 Jan 2017 06:47:30 GMT

Current Rate..................................... 36.0

The output to the command "sh client detail" shows the wireless 6200 NIC card can support up to 36 Mbps only.

The output from the AP C9_18F_AP3 is of no use because the data transfer counter are very low. It looks like this AP isn't being used at all (either that or the AP was recently rebooted).

The output from C9_08F_AP4 is interesting. Interface F0 has a lot of traffic. It also shows a tiny "hit" with line error.

Can you please provide the complete output to the command "sh ap auto-rf 802.11b C9_08F_AP4"?

Also provide the output to the command "sh advance 802.11b summary".

Hi Leo,

RickTan1981 — Wed, 04 Jan 2017 07:04:19 GMT

Hi Leo,

Please check the command output.

AP C9_18F_AP3 just for testing reboot recently.

Firmware 7.2.103.X is pretty

Leo Laohoo — Wed, 04 Jan 2017 07:54:23 GMT

Firmware 7.2.103.X is pretty old. Are you able to upgrade the controller to 8.0.140.0?

I see nothing wrong with the file output wlcap.txt.

Can you provide the output to the command "sh ap auto-rf 802.11b C9_08F_AP3"?

Are the people complaining of slow responses all coming from the 8th floor?

HI Leo,

RickTan1981 — Wed, 04 Jan 2017 08:20:58 GMT

HI Leo,

Thanks for your suggestion. Have you fix same issue by upgrade firmware before?

My boss complain the wireless slow recently. So I have to find the solution.

Here is AP3 output.

I don't see anything wrong

Leo Laohoo — Wed, 04 Jan 2017 09:15:16 GMT

I don't see anything wrong with these output.

The only thing I can see weird are the NIC cards are rated for low speed.

Try updating the wireless NIC

Leo Laohoo — Wed, 04 Jan 2017 23:25:45 GMT

Try updating the wireless NIC drivers to whatever latest one is available.