Low data rate 802.11ax with 9115axi

[Torken]

Hello,

I bought some cisco 9115 axi ap , it works correctly except the data rate.

When the computer is connected to the 2960x switch, the data rate is 1gbps

When the computer is connected to the ap (using 802.11ax and very close) which is connected to the previous 2960x switch, the data rate does not exceeds 350mbps

Note : Only one computer is connected to the AP when tests are performed

I don't understand why the data rate is so low... When I read the datasheet the physical data rate is 5.38 Gbps. I should at least get 1gbps (I know my switch is not compatible with 802.3bz)...

Please help me it's really annoying, I have pretty good hardware but it doesn't work the way I want

[Leo Laohoo]

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@Torken wrote:

the data rate does not exceeds 350mbps

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• What is the exact model of the wireless NIC and what is the driver it is running? 
• Try "replicating" the issue with, say, a smartphone or a tablet and comparing the results? 

[Torken]

There are informations about my computer NIC :

- Intel(R) Wi-Fi 6 AX201 160MHz

- PCI\VEN_8086&DEV_02F0&SUBSYS_00708086&REV_00\3&11583659&0&A3

- driver version : 22.10.0.7

I tried with another computer, with 802.11ac, I have the same issue (~300mbps)

With my 802.11n smartphone I have 250mbps (What do you think?)

Note : I didn't configure radio settings in my EWC (defaults values)

[Leo Laohoo]

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@Torken wrote:

- driver version : 22.10.0.7

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That is a very old firmware.

Try upgrading the firmware to something more recent.

[Torken]

Ok, I thought that Windows will download automatically the latest driver version, I don't know why I am still using this operating system.

Now my driver is 20.30

Anyway, the data rate still 350mbps

Do you have any others suggestions ?

I think the problem isn't endpoint device (maybe I am wrong)

[Leo Laohoo]

Intel AX200 NIC drivers can be found HERE.

What Data Rates are enabled?

In the WLC, post the complete output to the following command:

grep include <AP NAME> "show advanced 802.11a summary"
grep include MAC.Address|Device.Type|AP.radio.slot.Id|Radio.Signal.Strength.Indicator|Signal.to.Noise.Ratio "sh client detail <MAC ADDRESS>"

[Torken]

I don't know why but the output of theses 2 commands are empty if I put an AP name instead of <AP NAME> (I enabled the shell)

I never used shell before

If I use your command I have an error :

EWC#grep include <AP NAME> "show advanced 802.11a summary"
%Error: cannot overwrite existing file        ^
% Invalid input detected at '^' marker.

[Torken]

hello,

There are the output of both commands :

EWC#sh ap dot11 5ghz summary | i AP06-SET
AP06                            ac4a.56e4.xxxx  1       Enabled        Up            40     *3/6 (11 dBm)   (36,40)*             
EWC#$ail | i Client MAC Address|Protocol : 802|AP slot|Current Rate|Radio Signal Strength Indicator|Signal to Noise Ratio
Client MAC Address : d8f8.83xx.xxxx
AP slot : 1
Protocol : 802.11ax - 5 GHz
Current Rate : m11 ss2
  Radio Signal Strength Indicator : -35 dBm
  Signal to Noise Ratio : 59 dB

What do you think?

[JPavonM]

You are maybe using eWLC so try these commands:

sh ap dot11 5ghz summary | i <AP_NAME>
sh wireless client mac <CLIENT_MAC> | i Client MAC Address|Protocol : 802|AP slot|Current Rate|Radio Signal Strength Indicator|Signal to Noise Ratio

For me it shows something like this:

sh ap dot11 5ghz summary | i DExxx
DExxx 0011.2233.4455 1 Enabled Up 40 *2/6 (14 dBm) (36,40)* REAP
!
sh wireless client mac aabb.ccdd.eeff | i Client MAC Address|Protocol : 802|AP slot|Current Rate|Radio Signal Strength Indicator|Signal to Noise Ratio
Client MAC Address : aabb.ccdd.eeff
AP slot : 1
Protocol : 802.11ax - 5 GHz
Current Rate : m9 ss1
Radio Signal Strength Indicator : -56 dBm
Signal to Noise Ratio : 38 dB

Please notice Windows link speed is not what marketing says about the wireless adapters, as this is maximum speed under specific configs and conditions.

Also notice there is a cosmetic issue in the output of the "Current rate" that I've reported to TAC to solve it (Intel AX chipsets have 2SS and they are only reported as 1SS on COS APs).

HTH
-Jesus
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[Torken]

hello,

what do you think about these results ?

EWC#sh ap dot11 5ghz summary | i AP06-SET
AP06                            ac4a.56e4.xxxx  1       Enabled        Up            40     *3/6 (11 dBm)   (36,40)*             
EWC#$ail | i Client MAC Address|Protocol : 802|AP slot|Current Rate|Radio Signal Strength Indicator|Signal to Noise Ratio
Client MAC Address : d8f8.83xx.xxxx
AP slot : 1
Protocol : 802.11ax - 5 GHz
Current Rate : m11 ss2
  Radio Signal Strength Indicator : -35 dBm
  Signal to Noise Ratio : 59 dB

[Scott Fella]

Marketing got the best of you, to be honest.  Keep in mind that wired and wireless is completely different and you never compare the two.  Also the speed or throughput rate you get is dependent of the AP, device radio, band, channel width, etc.  Your ap is a Wifi6 capable access point, so you need to have a capable WiFi6 client to get the most out of that AP.  Don't fall into the whole marketing stuff, you will never achieve that in a live production network since there are many variables that affect speed and data rates and user experience on wireless. 

[Torken]

Hello,

Thanks for your answer

I have a capable 802.11ax radio client. I think there is a problem because I have almost the same data rate with 802.11n (not a significant data rate difference). I would be really disappointed if you were right.

I posted connexion details above, in answer to Leo Laohoo, tell me what do you think about that?

[JPavonM · Accepted solution]

Link speed is determined depending on the current MCS index (current rate), which depend on the SNR.

You can consult your current link speed here http://mcsindex.com/ (for your output look for MCS11 with 2 spatial streams under HE column, and move to the right under 802.11ax@40MHz; depending on the GI link speed could be between 490-575Mbps; but also depending if you are sharing the channel using OFDMA, it all depend on the tones).

For 802.11ac devices at the same AP distance, maximum data rate would be 400Mbps, and 300Mbps for 802.11n devices.

Remember this is link speed, not throughput.

It seems to me that your problem here is not about real link speed but throughput. The so called quality of experience depends on how many devices are attached to the same AP, but also on how many devices are sharing the medium, and the use of the medium they are doing. Throughput in 802.11 is about efficiency of the transmission during the time to transmit. Remember, you are unlikely to be the only one that is using the air to transmit at a certain time, so you have to share the medium with all of them. Unless you are on an isolated facility, or you have chosen an unused channel.

HTH
-Jesus
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[Torken]

Hello,

Ok, I know the MCS index table. Can I use 160 or 80 Mhz channel instead of 40Mhz ? It can make me happy

[JPavonM]

It's unlikely you can use 80-160 MHz channel width without overlapping neighbor networks. Doing so you would be affected by co-channel interference thus not achieving the objective you are looking for to transmit faster.

You can look for nearby networks using WinFi lite https://www.helge-keck.com/download.html and try to use a non-used channel and then increase channel width without overlapping any other network.

HTH
-Jesus
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