How to Fix Slow Wireless with Intel 4965 AGN

wireless

Possible Duplicate:
Slow wireless with an Intel 4965

We run Ubuntu 12.04, 32bit, with the current kernel 3.2.27-generic on an MSI EX700.

I've already added the 11n_disable=1 tweek, without whcih, wireless has been unusable.

Now, it works OK, but speedtest shows:

Windows XP - down 11.68mbps, up 2.07mbps

Ubuntu 12.04 - down 2.06mbps up 2.0mbps

We've disabled ipv6, tried static and dinamic IPs, tried both swcrypto=0 and swcrypto=1 options, none of whcih made any difference.

The problem may be the symptom of high packet loss. For example, here's the output of iwconfig after booting and testing the speeds:

wlan0     IEEE 802.11abg  ESSID:"amu"  
      Mode:Managed  Frequency:2.462 GHz  Access Point: 00:78:9E:FA:32:C8   
      Bit Rate=54 Mb/s   Tx-Power=15 dBm   
      Retry  long limit:7   RTS thr:off   Fragment thr:off
      Encryption key:off
      Power Management:off
      Link Quality=58/70  Signal level=-52 dBm  
      Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
      Tx excessive retries:11  Invalid misc:3627   Missed beacon:0

I've posted a help request before with lots of technical info and outputs.

Best Answer

(answer in progress)

The iwl4965/iwlegacy driver has had a number of regressions in the past, but they've usually been fixed.

The high invalid misc number may be related to your low throughput.

Please try/test/answer a couple of things, and ask me for a howto when needed:

Do you experience this problem with the Ubuntu 12.04 Desktop Live CD (which runs kernel 3.2.0-23, IIRC)?
Can you try using wicd instead of NetworkManager?
Can you compile and try the latest iwl4965 driver from the compat-wireless tree?
What is the manufacturer/model number of your router?
Does your laptop have bluetooth?

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Well Yes I have another solution, perhaps it could fits to your problem or not. I tried the same solution disabling the N network mode, it works but it turns out not to work under N wireless network.

In my case, I was under a WEP encrypted wireless network, this was the reason why I was navigating to slow, with N mode enabled.

Just enable your N wireless mode and change your security wireless network to WPA2 , it will resolve your problem.

regards!

Ubuntu – Wifi Connection Issues on Ubuntu 16.04

Sometimes, wireless gets disconnected because of settings in the router. First, most routers are set by default to the lowest common denominators including WPA and WPA2 auto-select, AES and TKIP auto-select and, worse of all, auto channel select. Here is a very interesting thread about auto channel select and why it doesn’t work at all well: https://superuser.com/questions/1311149/why-do-wifi-routers-do-such-a-bad-job-of-channel-selection

First, check the settings in the router. WPA2-AES is preferred; not any WPA and WPA2 mixed mode and certainly not TKIP. Second, if your router is capable of N speeds, you may have better connectivity with a channel width of 20 MHz in the 2.4 GHz band instead of automatic 20/40 MHz, although it is likely to affect N speeds. I also have better luck with a fixed channel, either 1, 6 or 11, rather than automatic channel selection. Also, be certain the router is not set to use N speeds only; auto B, G and N is preferred. After making these changes, reboot the router.

Next, I recommend that your regulatory domain be set explicitly. Check yours:

sudo iw reg get

If you get 00, that is a one-size-maybe-fits-all setting. Find yours here: http://en.wikipedia.org/wiki/ISO_3166-1_alpha-2 Then set it temporarily:

sudo iw reg set IS

Of course, substitute your country code if not Iceland. Set it permanently:

sudo nano /etc/default/crda

Change the last line to read:

REGDOMAIN=IS

Proofread carefully, save and close the text editor.

After rebooting the router and the computer, please tell us if there is any improvement.

Best Answer

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