Slower Upload than Download over AC WiFi, driver issue (MT76) or missing optimization?

Hello, I'm using OpenWRT 22.03.02 on two Netgear WAC104s (neutered R6220). The issue I'm trying to understand is that my wireless upload speeds seem to be capped around 200Mbps on my 5Ghz/AC SSID.

This limit is seen over iperf3 and speedtest(dot)net. Download speeds are not affected and I regularly achieve >350Mbps down. I've also done the same tests over wired devices just to confirm it isn't a hardware bottleneck on the main WAC operating as the router, and I get 500Mbps symmetrical on speediest (what I pay for), and full gigabit over iperf3.

Things I've tried to remedy the situation are: testing different transmit powers, setting the least congested channel, setting the cipher to AES only.

Are there any different drivers I could try? Or am I possibly ignoring some settings in the wireless menu? any suggestions would be appreciated

Apologies for hijacking your post.

I can't help you with your problem, but maybe you could kindly post your /etc/config/wireless file? (I understand your AP seems to be mostly identical to the R6220, right?)

I can only get the 5 GHz radio working on my R6220, somehow 2.4 GHz doesn't come up?! ;-(

Here's what I currently have:

config wifi-device 'radio0'
        option disabled '0'
        option type 'mac80211'
        option channel '11'
        option band 2g
        option path '1e140000.pcie/pci0000:00/0000:00:01.0/0000:02:00.0'
        option htmode 'HT20'
        option legacy_rates '0'
        option country 'DE'

config wifi-iface 'default_radio0'
        option disabled '0'
        option device 'radio0'
        option network 'lan'
        option mode 'ap'
        option key 'theSecret'
        option disassoc_low_ack '0'
        option ssid 'mySSID'
        option short_preamble '0'
        option encryption 'psk2+ccmp'


config wifi-device 'radio1'
        option disabled '0'
        option type 'mac80211'
        option channel '52'
        option band 5g
        option path '1e140000.pcie/pci0000:00/0000:00:00.0/0000:01:00.0'
        option htmode 'VHT80'
        option legacy_rates '0'
        option country 'DE'

config wifi-iface 'default_radio1'
        option disabled '0'
        option device 'radio1'
        option network 'lan'
        option mode 'ap'
        option ssid 'mySSID'
        option encryption 'psk2+ccmp'
        option key 'theSecret'
        option disassoc_low_ack '0'

This is under OpenWrt 22.03.2 r19803-9a599fee93.

Many thanks in advance for your help.

Hi
Here is my (edited) config for a R6220 used as an AP.
note : I'm using a low transmit power. You may want to adjust this.

config wifi-device 'radio0'
	option type 'mac80211'
	option path '1e140000.pcie/pci0000:00/0000:00:01.0/0000:02:00.0'
	option htmode 'HT40'
	option country 'FR'
	option cell_density '0'
	option hwmode '11g'
	option txpower '14'
	option channel '6'

config wifi-iface 'default_radio0'
	option device 'radio0'
	option network 'lan'
	option mode 'ap'
	option encryption 'psk2'
	option key 'xxxxxx'
	option ssid 'wifi2'

config wifi-device 'radio1'
	option type 'mac80211'
	option hwmode '11a'
	option path '1e140000.pcie/pci0000:00/0000:00:00.0/0000:01:00.0'
	option htmode 'VHT80'
	option country 'FR'
	option cell_density '0'
	option txpower '14'
	option channel '36'

config wifi-iface 'wifinet1'
	option device 'radio1'
	option mode 'ap'
	option ssid 'wifi5'
	option encryption 'psk2'
	option key 'xxxxxx'
	option network 'lan'
1 Like

Thank you.

This is not for OpenWrt 22.x, right? Because I see the old option hwmode ... options...

I've done a lot of digging here on the forum, and it becomes more and more obvious that there is some driver issues for the R6220. Seems it needs to mature a bit so that all problems are fixed...

Yes, it's running on master snapshot. It should be the same for 23.02. Sorry I forgot to mention this.

Why old ? Is it deprecated ? I can't find this info. I have simply setup wifis using Luci.

I own two and manage a third one: I'm using mostly 5GHz and can achieve 40 MB/s when transfering file from a desktop to a laptop. I'm poorly using 2.4GHz (and old device from time to time), but it works as expected (12 MB/s). So far I'm satisfied by the performances that are according to hardware. I have used 19.07, 22.03, 23.02 and a lot of various snapshots on all these three models.

I have also read several issues reports but I can't figure out why (bad config, bad models ?).
Recently there was an issue for snapshot (Probable wifi regression in mt7621 snapshot) but that was a simple bug correctly the day after. I can't call this a driver issue, just a setback.

I have erased wifi config and recreated it from scratch. You're right, there is no more hwmode. At least I know that the syntax is now uptodate. Thank you.

config wifi-device 'radio0'
	option type 'mac80211'
	option path '1e140000.pcie/pci0000:00/0000:00:01.0/0000:02:00.0'
	option band '2g'
	option htmode 'HT40'
	option channel '6'
	option txpower '17'
	option country 'FR'
	option cell_density '0'

config wifi-iface 'default_radio0'
	option device 'radio0'
	option network 'lan'
	option mode 'ap'
	option ssid 'wifi2'
	option encryption 'psk2'
	option key 'xxxxxx'

config wifi-device 'radio1'
	option type 'mac80211'
	option path '1e140000.pcie/pci0000:00/0000:00:00.0/0000:01:00.0'
	option channel '36'
	option band '5g'
	option htmode 'VHT80'
	option txpower '15'
	option country 'FR'
	option cell_density '0'

config wifi-iface 'default_radio1'
	option device 'radio1'
	option network 'lan'
	option mode 'ap'
	option ssid 'wifi5'
	option encryption 'psk2'
	option key 'xxxxxx'
1 Like

Check this out. It says for hwmode:

DEPRECATED since 21.02.2, replaced with band

When I referred to "driver issues" I referred to the 2.4 GHz radio not working. There is evidence of several people having that problem here in the forum, so this is why I came to the conclusion.

1 Like

To confirm, what you did is remove the config file, and run the wifi config command? Or did you revert to the original Netgear firmware, and then back to OpenWrt?

I have read this several times myself. Unfortunately I have never had such issue (lol ?). All I can say is that the three models I own/manage are working fine with 2.4GHz. The one managed runs on 22.03 and mine are on latest snapshot.

Yes, than I reconfigured to my wish (channel, power, ssid, password).

1 Like

Thanks, did that already, but in my case it didn't help. 2.4 GHz radio still "invisible" and not initialized... :frowning:

Use a completely default configuration-- the only change to make is set the country (must be the same country on both radios) and enable the default unencrypted AP.

Check the log file and run iw dev to see if there was any attempt to bring up an AP.

The final troubleshooting step is to flash back to stock firmware to check if there is a hardware failure.

2 Likes

if you were using a customized version of OpenWRT with newer kernel than 5.15+, then following pr features a fix: https://github.com/openwrt/openwrt/pull/11220. There are different proposed fixes for "wifi lost issues" on older kernels also, but not sure if they would fix your problem. It's a long discussion over there.

2 Likes

Thanks. I already did what you advised in the 1st paragraph, but it didn't help.

Now I did something very crazy (duh!) -- I power-cycled the box. And now it works... :man_facepalming:t2:

Feel stupid that I hadn't tried that before...

Thanks. I was using an out-of-box version of OpenWrt.

If I hadn't solved my problem by power-cycling the box, I might have tried compiling my own with the patch included... Maybe next time... :wink: