AR9271 ping spikes

[linux-wireless-misery]

I am experiencing disruptive ping spikes every 15-20 seconds lasting 2-3 sec. Over 500ms or outright packet drops. Have the same behaviour with 2 separate AR9271 USB cards (Netgear WNA1100 and TP-Link TL-WN722N).

Tested on Lubuntu 16.x, Fedora 24, Kali 2016.1 and 2. Kernels 4.1 to 4.8. Two separate computers. It also happens on Windows, but: -the spikes happen in similar timeframes, but aren't nearly as disruptive (two or three ~200ms roundtrips, rarely any packet loss) -it gets fixed completely with Streaming Mode enabled in WLAN Optimizer (http://www.martin-majowski.de/faq.html)

Any ideas as to what's wrong?

[olerem]

1. channel scan. Depending on your usb host controller channel scan can take from 8 till 30 seconds. The interval of scan is configured by wpa_suplicant.
2. USB 3 controller performs better then USB2, even if this is USB2 adapter.
3. led blinking. disable it and you will get better results.

[olerem]

1. don't forget to update firmware. latest firmware can provide some optimisation if bound with latest kernel.

[satvilla]

I have the same problem. I try to compile the firmware with no luck; I also try to disable hwcrypt.

How can I disable the led blinking or change the wpa_suplicant?

This problem only happens when I have the option WMM enabled on the router, so it means, it only happen on wifi 11n, not 11g (tested).

Thanks in advance.

[olerem]

Then most probably it in an issue with the router firmware. Google for "WMM bad ping" or some thing like this. In my tests i use TL-WDR4300 with openwrt, and noticeable ping change is only each 3 minutes for max 10 seconds. The latency is higer, but no packet drops..

[linux-wireless-misery]

@olerem, you were right at the outset, it is wpa_supplicant triggering CTRL-EVENT-SCAN. Now, the problem is that I can't fix it: wpa_cli doesn't respond to set or reconfigure commands out of the box, and I can't make wpa_supplicant.service read wpa_supplicant.conf. I even managed to delete /sbin/wpa_supplicant at one point somehow! What a f*****g mess.

[linux-wireless-misery]

@satvilla I still get spikes after turning WMM off, but they're not as severe now (no packet loss anymore).

[olerem]

Try to disable HT40 if enabled.

[linux-wireless-misery]

No difference.

[erikarn]

hiya,

it may just be network manager triggering background scans.

-adrian

On 9 November 2016 at 07:14, linux-wireless-misery <notifications@github.com

wrote:

No difference.

— You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub https://github.com/qca/open-ath9k-htc-firmware/issues/112#issuecomment-259437777, or mute the thread https://github.com/notifications/unsubscribe-auth/ABGl7Z0LiLw5wpQ4fepxrvxiy-7-RY_4ks5q8eNPgaJpZM4KscJj .

[satvilla]

@olerem I'm sure the problem is not the router, because it only happen with this wifi client. My real problem is when I try to watch a video on HD over the wifi lan, each few minutes the video stops, because the buffer is empty, until the buffer grow to the 100%. It also happen with SD content but less often because the buffer is bigger. The cause of that problem is the ping of the computer, I monitorize that and it change from 6ms to 600-1000+ ms every few minutes.

I want to try to disable the blink or the wpa_supplicant, if it can help, but I'm not an experienced linux user (in fact I'm proud to have been able to compile this firmware), how can I do that?

[soyersoyer]

From: https://blogs.gnome.org/dcbw/2016/05/16/networkmanager-and-wifi-scans/

You can "lock your WiFi connection profile to the BSSID of your access point" by entering your access point's BSSID under "Edit Connections..."

It works, no more spikes.