WAP371 802.11n stuck @72Mbps although 20/40Mhz channeling enabled

[xaviercrespin]

Hello,

I have installed a WAP371 in my office, and among other devices which connect in AC i have two Asus K551ln laptops wich connect via the 2.4Ghz (Radio 2) antenna, whatever i try i cannot get them to connect at 150Mbps, but only at the reduced rate of 72Mbps.

Here are some details you may ask before i go any further : 

• Wireless adapter : Mediatek MT7630E
• Operating system : Windows 8.1 x64
• Wireless adapter driver :  v5.0.51.0 (latest)
• WAP371 firmware : 1.1.2.3 (latest)

What i tried so far on the WAP371 in the Wireless/radio settings and did not work :

• disable completely Radio 1 (5 Ghz) (for the sake of trying anything...)
• from the  "Mode" dropdown menu i selected 2.4Ghz 802.11n (not 802.11 b/g/n)
• From the "channel bandwidth" dropdown i selected 20/40Mhz to supposedly enable channel bonding

What i tried on the laptops that did not work :

• Update the wireless adapter to latest driver
• disable power saving
• enable "WMM and games" mode

Any idea on what i should try next to make it work as intended? Can TKIP encryption have something to do with it?

in Advance, thank you,

XC.

[repham]

Dear xaviercrespin,

Thank you for using the Cisco Support Community.  My name is Remy, and I am an eSupport Content Developer for the Small Business Support community, and I hope to alleviate some of your issues.

We have emulated to the best of our ability your given network configuration in our labs; with our WAP371 unit, we disabled the 5GHz band, enabled the 2.4GHz band, in addition to changing the mode to 2.4 GHz 802.11n, and changing the Channel Bandwidth to 20/40 MHz.  

In our tests, with both one and two laptops, we consistently got about 86Mbps.  We have also tested other configurations, including using the 5GHz band, and received consistent results regarding our data rates.  Please note that there is a discrepancy between the maximum potential wireless throughput of the WAP, and the real-world wireless throughput that is available through your service provider.  It is possible that 72Mbps is the your true, real world data rate.  You can find more information regarding this discrepancy in this pdf: http://www.cisco.com/c/en/us/products/collateral/wireless/small-business-300-series-wireless-access-points/datasheet-c78-732143.pdf

If possible, please elaborate on the following questions to clarify your case:

• Have you ever been able to successfully connect to your WAP371 with a consistent data rate of 150Mbps?
• What tools are you using to measure your data rates?
• What is your proximity to the router?

I hope this clarifies some of your issues, and if you have any further questions, please don't hesitate to reply to this post.

Best,

Remy Pham

[xaviercrespin]

Hello,

Thank you for your answer!

To clarify, the 72Mbps i speak of is not a measurement, it's not the data rate, it's the connection rate indicated by the driver of the mediatek wireless adapter. It's also indicated in the windows 8.1 wireless status dialog windows.

This means that the wireless device is connected to only one channel of the 150Mbps AP.

The distance from the laptop to the WAP371 is, obstacle free, about 2 meters.

You should know that this 72Mbps indication is typical when 802.11n 150Mbps devices connect to only one channel (20Mhz) of a compatible 150Mbps AP, if connected to both channels (20+40Mhz) the device declares itself connected at a rate of 150Mbps (if the environment is right), connection rates that i have easily achieved on the very same laptops when using 40€ concurrent 802.11bgn 150Mbps wireless APs and having the two channels 20/40Mhz activated.

It shows exactly 72Mbps, on both laptops, not 73, not 71, which demonstrates precisely the issue explained above.

And speaking of measurement, i can reach, using SMB from server to client, a speed of 5000KB/s which is satisfying for a 72Mbps connection, so this is not the issue here, the issue is that i cannot get these laptops to connect to both channels 20/40Mhz of the WAP371.

Thank you for reading,

Regards, XC.