Clients Ubuntu and Android Problems - AP 1832

[marcelo.capela]

Hello everyone,

In the last few months, I have noticed a considerable deterioration in the signal of the 1832 APs. I work 3 meters away from an AP and I lose signal frequently. We also noticed that ubuntu and android clients connected on 2.4GHz wireless networks do not exceed 7Mbps.

I have other models (1600 and 1700) on the network that are not experiencing this problem.

Attached, I send the print of the incident. Has anyone ever experienced this?

Thank you very much in advance!

[Leo Laohoo]

---

@marcelo.capela wrote:

We also noticed that ubuntu and android clients connected on 2.4GHz wireless networks do not exceed 7Mbps.

---

2.4 Ghz is a very congested spectrum.  

Disable 2.4 Ghz and see if the RSSI and speed improves.

[marcelo.capela]

Hi Leo,

Unfortunately this is not an option as most of my clients connect to the 2.4GHz network.

Devices that support 5GHz do not have the same problem, only 2.4GHz.

[patoberli]

You still have some 2.4 GHz only clients? Otherwise I'd also suggest to at least partly disable 2.4 GHz for testing (like just the one accesspoint which your clients connect to). How is the noise and RSSI of your client while it's having issues and is connected to a 2.4 GHz channel?

[marcelo.capela]

Hi patoberli,

Yes, I still have clients that connect only at 2.4GHz, at least 60% of the environment.

Right now, one of them is like this:

RSSI: -41

SNR : 53

Client Actual Rate: 7Mbps

[Leo Laohoo]

What Data Rates are enabled?

[marcelo.capela]

Hi Leo, our Data Rate is configured like this:

1 Mbps - Disabled
2 Mbps - Disabled
5.5 Mbps - Disabled
6 Mbps - Disabled
9 Mbps - Disabled
11 Mbps - Disabled
12 Mbps - Mandatory
18 Mbps - Mandatory
24 Mbps - Supported
36 Mbps - Supported
48 Mbps - Supported
54 Mbps - Supported

[Leo Laohoo]

Just to test, turn off 2.4 Ghz.  Check if those Ubuntu computers are still having problems or not.

[marcelo.capela]

Hi Leo,

I performed the tests you requested and the problem persists.

Another test I did, a WLC with factory defaults and the latest firmware version available.

Clients connect for about 10 minutes with a good connection, but after that it goes back to 7Mbps. I tested it with another model, 1700 and the same doesn't happen.
I believe my problem is only with the 1832 models and not the WLC.

Are there any settings that cause this behavior and might be enabled?

[Leo Laohoo]

And this is happening to Ubunto OS and Android-based wireless clients only? 

How about Apple- or Windows-based OS?

For Ubuntu, what is the exact model of the wireless NIC and what is the exact version of the wireless NIC driver?

[marcelo.capela]

Hi Leo,

All client models and operating systems have problems when connected to an 1832, but only linux and android are "unworkable".

For example, being 3 meters away from an 1832 AP, my dell notebook with windows 10 has a connection speed of 64Mbps. If I connect to a 1700 installed for testing in the same position, I connect at 308Mbps.

I'm going deeper into testing this AP model, everything indicates that something in this model is problematic.

Unfortunately, of the 192 APs I own 150 are 1832.

[patoberli]

Which software release are you running? Maybe you are hitting some MCS data rate bug.

[marcelo.capela]

Hi paroberli,

In production I have a WLC 5508 with OS 8.5.171.0.

In lab, I have a WLC 2504 with OS 8.5.182.0.

Client behavior is the same on both WLCs.

[patoberli]

To bad, then you are on a current release on the 2504. I guess time for TAC.

[Leo Laohoo]

Something does not add up. 

I understand Linux-based WiFi not working properly but Android too?  What firmware are these droids working on? 

Update the wireless NIC drivers of the Linux client.