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Using iperf to test throughput using Intel Centrino Advanced-N 6205, I'm getting 20Mbps up and 50Mbps down. AP is attached to 100Mbps switch so I expect 80-100Mbps as confirmed when doing the same test from Windows. I've disabled 802.11N but still get the same results, changed the swcrypto option, updated kernel to 3.14 I noticed that upload traffic generates "Invalid Misc" as reported by iwconfig. I've also stopped the network manager service and used wpa_supplicant to connect and still see the same problem.

wlan0     IEEE 802.11abgn  ESSID:"*****"  
          Mode:Managed  Frequency:5.785 GHz  Access Point: 88:DC:96:12:09:B3   
          Bit Rate=81 Mb/s   Tx-Power=15 dBm   
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:off
          Link Quality=46/70  Signal level=-64 dBm  
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:233   Missed beacon:0
user.dz
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user305247
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2 Answers2

3

If anyone else is looking at this, the resolution to my problem was to edit /etc/modprobe.d/iwlwifi.conf and add options iwlwifi 11n_disable=8 to the end.

Scott
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1

To solve this performance drop, we need to modify 3 options of iwlwifi module to :

Re-enable TX AMPDU aggregation (that was disable by default for iwldvm devices)

Disable an advanced technique that tries to minimize interferences between Wifi and Bluetooth signals

Disable hardware encryption and use software encryption instead

Try use:

 echo options iwlwifi bt_coex_active=0 swcrypto=1 11n_disable=8 | sudo tee /etc/modprobe.d/iwlwifi.conf

You now need to unload/reload iwlwifi module (or to reboot your computer).

sudo modprobe -r iwlwifi
sudo modprobe iwlwifi

For more details see this:

user72708
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