Very poor 2.4ghz performance on 2802i/3802i in mobility express.

[ockerlaura053]

I am looking for some pointers on how to debug the issue I am facing. Any commands or possible configuration.

I have two access points 2802i and 3802i in mobility express controller mode.

I am facing very poor performance in 2.4 ghz mode. I get almost 1mbps download and 2-5 upload. The ssid has 1,6,11 channels configured. SSID has platinum qos configured.

I have internet speed of 500/20mbps. When I move to 5ghz I can hit these speeds very easily without an issue.

I have tried creating a single 2.4ghz with only one client connected to access point and no improvements in speed. I have used iPhone 13, Lenovo thibkpad, MacBook Pro and all have the same results.

[marce1000]

      - FYI : https://www.cisco.com/c/en/us/support/docs/wireless/wireless-lan-controller-software/220877-troubleshoot-wireless-speed-issues.html

 M.

[Leo Laohoo]

@ockerlaura053 

Post the screenshots you've posted in other forums.  

[sardarjion]

I am the original poster on the Reddit. Here is the link to original issue - https://www.reddit.com/r/Cisco/s/fGN5frAFYJ

I uploaded the snapshot of the RF page. Is there any command I can run on AP to debug this more. Thanks. 

[sardarjion]

@ockerlaura053 Wow, you copy pasted my original post from Reddit here(https://www.reddit.com/r/Cisco/s/fGN5frAFYJ)

not sure I should be happy that you saved me posting here or offended that you just blatantly copied it from there. 

[Leo Laohoo]

@sardarjion 

What firmware are the ME APs on?

[sardarjion]

I tried with 8.10.196, 8.10.185, 8.5.160 and results are the same. 

[Leo Laohoo]

---

@sardarjion wrote:
I am facing very poor performance in 2.4 ghz mode. I get almost 1mbps download and 2-5 upload. The ssid has 1,6,11 channels configured. SSID has platinum qos configured.

---

Why 2.4 Ghz?  What is so unique about this wireless client that it has to use 2.4 Ghz over 5.0 Ghz?

What is the channel utilization of the channel being used by this wireless client?

---

@sardarjion wrote:
When I move to 5ghz I can hit these speeds very easily without an issue.

---

Exactly.  (In the other forums, at least one of those who responded is a NAM Wireless TAC engineer.)

What kind of wireless client was used to "measure" the state of 2.4 Ghz?  I want to know the exact model of the wireless NIC.

[sardarjion]

---

---

Why 2.4 Ghz?  What is so unique about this wireless client that it has to use 2.4 Ghz over 5.0 Ghz?

What is the channel utilization of the channel being used by this wireless client?

---

I have dragonboard which is similar to raspberry pi and has only 2.4ghz. This is the real motivation to test and use 2.4Ghz. Here is the snapshot from the dashboard with only one client connected to SSID 

The below snapshot of the client connection info. 

Now, in order to rule out issue with this particular SOC, I tried connecting iPhone13, Lenovo T14s (Qualcomm FastConnect 6900 Wi-Fi 6E Dual Band Simultaneous (DBS) WiFiCx Network Adapter) and older Lenovo with Intel(R) Dual Band Wireless-AC 8265.

I have the same results of download speeds hitting 1.5mbps and upload close to 15-20mbps. I ran two speedtest at around 10 minutes interval.

What surprises me is that I am getting way better upload speeds than download and the connection has 500/20 mbps plan. 

---

Exactly.  (In the other forums, at least one of those who responded is a NAM Wireless TAC engineer.)

What kind of wireless client was used to "measure" the state of 2.4 Ghz?  I want to know the exact model of the wireless NIC.

---

Yes, I know that 5Ghz is preferred any day. All I expect is that I should get atleast 10-15mpbs download on 2.4Ghz.

[Rich R]

That screenshot shows you using 80MHz channels for 5GHz but no option to configure 2.4GHz so I assume 20MHz channels?
Also not clear what the "RF Optimization does" - you might want to play with the settings there and turn it off too.
Also look at the CLI config rather than just GUI.
Obviously you will never get the same throughout on 2.4GHz 20MHz compared to 5GHz 80Mhz but if working properly then you should get more than what you're seeing at the moment.
https://mcsindex.net/
Also depends on a whole lot of other settings and features.

Above all else remember 2.4GHz is typically extremely congested so as Leo asked - what is the channel utilisation?
And why are you even trying to use 2.4GHz?

[sardarjion]

Here is the detailed view of channel utilization. As mentioned in the other post, I have small SOC similar to raspberry pie which only has 2.4ghz. 

I only expect a speed of 10-15mpbs so that it is usable. With speeds of 1mbps download, it is very hard to do anything on the device due to lags. 

[Leo Laohoo]

Geez.  A CU of 42%.  

Try to simulate the connection & speed using Ubiquiti's WiFi Tool.  

(The SoC probably have a 1x1.)

1. Pick 2.4 Ghz, 20 Mhz and a CU value of 42. 
2. Next, on the right hand side of the wireless client is a "+".  Click that.
3. Under WiFi Standard, pick WiFi 4.
4. In the 2.4 Ghz column, choose 20 Mhz and MIMO of 1x1.  Disable 5.0 Ghz radio and hit Create.

I am getting 31.4 Mbps in the simulation.  

And that is the speed you are getting now.  

[sardarjion]

Thanks Leo, thanks for sharing this tool. 

Yes, with the change of making 18mbps as mandatory and disabling 12mbps, I am now getting 30mbps approx in download. 

[Leo Laohoo]

---

@sardarjion wrote:
I am now getting 30mbps approx in download. 

---

And that's the "best" you can squeeze out of a "classic" wireless 2.4 Ghz client with 1x1:1 MIMO.

[sardarjion]

The only surprising part is that after executing the commands I mentioned in the previous post, I still see 12mbps set to mandatory. I was expecting only 18mbps as mandatory.

(Cisco Controller) >show 802.11b

802.11b/g Operational Rates
802.11b/g 1M Rate............................ Disabled
802.11b/g 2M Rate............................ Disabled
802.11b/g 5.5M Rate.......................... Disabled
802.11b/g 11M Rate........................... Disabled
802.11g 6M Rate.............................. Disabled
802.11g 9M Rate.............................. Disabled
802.11g 12M Rate............................. Mandatory
802.11g 18M Rate............................. Mandatory
802.11g 24M Rate............................. Supported
802.11g 36M Rate............................. Supported
802.11g 48M Rate............................. Supported