Client experiencing slowness in data rates on wireless

[Rajesh Kumar Reddy]

I have two C9800-40 WLCs on HA with C9130 access point models, when the client laptop is connected to Wi-Fi, the one which connected over AC shows max speeds of 140 or 180mbps and the one which connected on AX show 574mbps max speeds.

Channel width is configured to "best"

How can we achieve max rates. please suggest anything related to configuration that can be considered to achieve max throughput

[Leo Laohoo]

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@Rajesh Kumar Reddy wrote:
I have two C9800-40 WLCs on HA with C9130 access point models,

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What firmware is the WLC on?

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@Rajesh Kumar Reddy wrote:
when the client laptop is connected to Wi-Fi

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What is the wireless NIC of the client laptop and what is the version of the wireless NIC driver.  Use the following DOS command to extract the information:  

netsh wlan show drivers

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@Rajesh Kumar Reddy wrote:
Channel width is configured to "best"

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Change it to 40 Mhz. 
 

[Rajesh Kumar Reddy]

Hello Leo Laohoo,

Thanks alot for your immediate response.

Is something related to firmware that will restrict the throughput speeds ?

Also Pls confirm that changing channel width to 40Mhz will actually reduce the speeds right - I know more channels are available to avoid the interference but throughputs will be less ? Correct me if I am wrong.

Thank you

[Leo Laohoo]

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@Rajesh Kumar Reddy wrote:
Pls confirm that changing channel width to 40Mhz will actually reduce the speeds right - I know more channels are available to avoid the interference but throughputs will be less ? Correct me if I am wrong.

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This is a fallacy.  

20- or 40 Mhz is ideal when there are OTHER nearby WiFi networks.  Using 20- or 40 Mhz channel bonding means better use of the allowed channels.  This means the APs have more channel options to use in the case of co-channel interference.  

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@Rajesh Kumar Reddy wrote:
Is something related to firmware that will restrict the throughput speeds ?

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Of course.  

For Realtek RTL88xx, the wireless NIC driver should be, at a minimum, 6001.10.352.0 (and later).  Refer to CSCwf03870. 

For Intel-based AX2xx, the wireless NIC drivers should be 22.200.2.1 (and later) or 22.220.0.0 (and later).  Refer to CSCwe50033. 

[Rajesh Kumar Reddy]

Thanks again Leo Laohoo

So, I would be considering here changing the channel width to 40Mhz and updating the drivers to latest release.

Hope that should fix my slowness and increase in data rates & throughput 

That is what your suggestion is right ?

Or else please suggest if anything additional to it I can look, Also the running WLC is running in "17.6.5" code.

Windows chipset model: Realtek RTL8822CE 802.11acPCIe adapter

Driver version: 2024.10.227.0

[Leo Laohoo]

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@Rajesh Kumar Reddy wrote:
Windows chipset model: Realtek RTL8822CE 802.11acPCIe adapter
Driver version: 2024.10.227.0

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Keeping up-to-date with Realtek wireless NIC drivers is a nightmare!  

Unlike Intel support website, Realtek website does not allow anyone to download the wireless NIC.  If if I have to find a Realtek wireless NIC driver it will have to be in some dodgy websites.  

This is why we refused/rejected the next batch of laptops for refresh because someone (without consulting us) picked ones with Realtek wireless NIC because that particular sub-model was the cheapest.  The new batch now comes with Intel-based AX2xx wireless NIC card.  

[Rajesh Kumar Reddy]

Hello Leo Laohoo

I am unable to open the below "For Realtek RTL88xx, the wireless NIC driver should be, at a minimum, 6001.10.352.0 (and later).  Refer to CSCwf03870"

Could you please share the output of this CSCwf03870 to view it further.

Thanks you

[Leo Laohoo]

Try this:  

https://bst.cisco.com/quickview/bug/<BUG ID NUMBER>

[JPavonM]

@Leo Laohoo that defect CSCwf03870 is for Cisco internal access only.

[Leo Laohoo]

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@JPavonM wrote:
that defect CSCwf03870 is for Cisco internal access only.

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Beautiful.  

/s

[Rich R]

Yes they've hidden it now!  Sometimes they do that by mistake, sometimes it happens because TAC engineer or developer forgets to tick the box confirming that the bug has been reviewed and is not security sensitive and sometimes they do it intentionally because Cisco considers the information to be embarrassing.  Whatever the reason - it's very irritating.  They used to have an option to report it but they removed that a little while ago - in other words they just don't care about it anymore.  Your only options are to open a TAC case and ask TAC for the info or request it via your Cisco SE - so much unnecessary waste of time.  Instead of making things easier they make them more difficult!

[marce1000]

                    >... to configuration that can be considered to achieve max throughput
   - Have a checkup of the  C9800-40 WLC(s) configuration with the CLI command show tech wireless ; feed the output into :
                                         Wireless Config Analyzer

  - Use latest advisory software version on the controller(s) ,  :
                                         https://software.cisco.com/download/home/286316412/type/282046477/release/Cupertino-17.9.4a

  - Other useful statistics concerning client  performance  can be observed with :
                                          https://www.cisco.com/c/en/us/support/docs/wireless/catalyst-9800-series-wireless-controllers/217738-monitor-catalyst-9800-kpis-key-performa.html#anc6

 M.

  - 
                                                          

[JPavonM]

@Rajesh Kumar Reddy the driver your laptop is using is not the last one and it last 1-year, there are 5 new version out there and now the current one is 2024.10.228.5 (https://catalog.update.microsoft.com/Search.aspx?q=Realtek%20RTL8822CE%20)

The problem with MS Catalog is that thre are no Release Notes so to see the fixed defects and security issues.

Check your manufacturer support page to see for the updated drivers, or check here for the latest ones:
https://www.station-drivers.com/index.php/en/component/remository/Drivers/Realtek/Wireless-(Wifi)/RTL8821CE-RTL8822CE-RTL8723DE-RTL8814BE-RTL8822BE.../orderby,2/page,5/lang,en-gb/?Itemid=0

Realtek RTL8723DE/8822CE/... Wireless LAN Version 2024.10.228.3 WHQL:
- Release note: - Fixes an issue where a system connected to a wireless access point (AP) disconnects from the AP unexpectedly. (RTL8822CE)