Buggy 5GHz WiFi on GL-MT6000

[27leguas]

I have just bought a GL-MT6000 and have found a very annoying bug which affects the 5GHz WiFi.
Firmware Version: 4.6.8 OpenWrt 21.02-SNAPSHOT r15812+1076-46b6ee7ffc / LuCI openwrt-21.02 branch git-22.335.71649-0ecaf74

The bug shows up with a specific combination of WiFi parameters that reduces download speed from 320Mbps to 10 Mbps, and upload from 320Mbps to 170Mbps

Some of the configuration parameters for context:

My WiFi is configured in the regulatory domain of Germany.
5GHz WiFi is the one affected by the buggy behavior.
2.4GHz , as far as I have tested, runs fine.
WiFi security: WPA2-PSK/WPA3-SAE (clients connect using WPA2-PSK)

The problematic combination of WiFi parameters involves 80MHz bandwidth with some specific channels:
-Bandwidth: 80MHz Channel: any of [36,40,44,48] Tested Payload Speeds on clients: down 10Mbps, up 170Mbps (almost always)
-Bandwidth: 80MHz Channel: any of [52,56,60,64] Tested Payload Speeds on clients: down 10Mbps, up 170Mbps (most of the time)

The non problematic combinations:
-Bandwidth: 80MHz Channel: any of [100,104,108,112,116,120,124,128] Tested Payload Speeds on clients: down 360Mbps, up 360Mbps (always)

Tested using the following speed test Apps on Android: Speedtest (Ookla), Fast.com, Wifiman (Ubiquiti)

The Wifiman App reveals not only the effective payload throughput but also the actual link speed of the PHY layer during the test.

Wifiman reveals very low speed on the download link when the bug shows (15Mbps or 32Mbps on the PHY layer) while showing the expected 433Mbps on the uplink.

When I configure any non-problematic combination of 80MHz bandwidth, both links (up and down) show 433Mbps on the PHY layer and throughput is around 360 Mbps on both directions.

I haven't found any information about this bug.
Any solution?

Help would be appreciated.

[bruce]

Is it possible that there are too many WiFi devices on the channel between CH36-CH64, resulting in a significant rate drop?

However, there are also many WiFi devices in the office, but I tested on my side and did not reproduce any obvious rate decline with same as your configurations in v4.7.0.

Test in Android phone:

Notice: since the network speed (per capita) in the office is not very high, so I used the speed test server built in the lab.

Thus, when CH100 and above channels are available, probably there are many WiFi devices in CH36-CH64 which will have an impact.

[27leguas]

Thanks to Bruce, for his quick response and his attempt to reproduce the problem.

After spending two days testing with different devices, I have come to the conclusion that it is a compatibility issue between some very specific models of WiFi device and the GL-MT6000 router.

In my case, the most problematic devices have been two identical units of "Huawei Mate 20 Lite" phone and to a lesser extent a "Doogee t30 Ultra" tablet.

Both phones showed identical disastrous results in speed tests:

• "Huawei Mate 20 Lite" Phone (2 different units, same results): (download 2.5-10Mbps ping: 600-2500ms upload:70-120Mbps) on all channels when using 80MHz

This same phones show correct results when paired with other APs of other brands (Tp-Link, Asus, Cisco).

The "Doogee t30 Ultra" tablet only showed poor results on some occasions and exclusively when using the channels [36,40,44,48] while obtaining correct speeds for the rest of the WiFi channels and other bandwidths other than 80MHz.

• "Doogee T30 Ultra" tablet: (download 10-40Mbps ping: 10-25ms upload:150-250Mbps) when using channels [36,40,44,48] 80MHz
• "Doogee T30 Ultra" tablet: (download 250-250Mbps ping: 10-25ms upload:250-350Mbps) when using channels other than [36,40,44,48] 80MHz

The fact that three different devices, although two of them identical, showed such bad results made me suspect about router malfunction and not the devices.

After the publication of my first message and taking more time, I have carried out tests using more devices and I have come to the conclusion that the problem appears exclusively when the WiFi connection is made between some specific device models and the GL-MT6000 router.

I have also tested other devices using the same 80MHz configuration with perfect results:

• 2018 iPad: (down:170-400Mbps ping: 4-10ms up:170-400Mbps)
• Laptop NIC AX200: (down: 250-400Mbps ping:4-10ms up:250-400Mbps)
• CMF Phone 1: (down:270-370Mbps ping: 4-10ms up:250-350Mbps)

I think it is worth drawing some conclusions from what has happened to me:

• There are incompatibilities for some specific combinations of WiFi clients and WiFi APs.
• If I do tests and they are not satisfactory, I must try other devices that must be of different brands and models.
• Phone "Huawei Mate 20 Lite" is incompatible with GL-MT6000's 5GHz WiFi
• Some other devices may have specific incompatibilities depending on the parameters of the connection.
• The 5GHz WiFi connection of the MT6000 is picky when it comes to client compatibility, at least in the current firmware version.

All tests were conducted 2 meters away from the router. Speed tests were performed sequentially on different devices (not concurrently). Between 20 and 30 tests were carried out per device at different times of the day.

I hope my experience will be useful to other users.

[xize11]

Will it work better when force disabling the 802.11w option (not optional but forced disabled) and set it to wpa2?

For the 802.11w option you need to go to system -> advanced settings -> click the link -> login in luci user: root, password same as gl ui.

Then navigate to network -> wireless click on edit on the band your issue occurs, then scroll down and there you can find it in one of these tabs.

I have readed a conversation about incompatbility on certain devices on the openwrt git issue/pull request tracker and i remember them talking about a newer wpa2 standard in which 802.11w is required, however some devices especially Apple devices showed incompatibilities the latter issue is not OpenWrt though but a bad implementation of devices 802.11w handling, as workaround this issue they recommend to disable it.

I wonder if this change some issues for your Huawei phone.

^ if that doesn't work, then please undo this option and try to uncheck Disassociate On Low Acknowledgement

Very interested to hear if anything changed and what it changed

[lecmipahu]

802.11w issues typically present themselves with not being able to associate with SSID at all. This shouldn’t affect later link rate like described above.

[27leguas]

My GUI didn't have the 802.11w option or is not at the place you told me.

[Igor]

I have an Asus Vivobook 15 laptop, Wi-Fi Intel AC9462
I have the same problem, I have to periodically disconnect from Wi-Fi and connect again. Because the download and upload speed suddenly flares up. At the same time, there is no such problem with other routers. I connected the Tplink router with a cable to the MT6000 and distributed Wi-Fi from it. and enjoy the steel connection. I would really like this bug to be fixed

[27leguas]

I added Motorola Moto G73 (two different units) to the 80MHz tested devices list.
Same problem.
Runs fine for the first 2-3 tests after connecting an then stuck with awful results for the download speed. down: 5 Mbps up: 180-200 Mbps. Results are fine with other Access Points: Asus, Tp-Link

All the devices that run fine are AX WiFi.
All the devices that have reduced speed are AC WiFi (not AX)

[Igor]

VHT-MCS periodically switches from 9 to 0. My laptop has Wi-Fi Intel AC9462 (does not support Wi-Fi6, only Wi-Fi5). Accompanied by a decrease in transmission speed. How can I prevent this parameter from switching from 9 to 0? There is another TPLink router nearby and there is no such problem
Also, there is no such problem on phones and laptops with Wi-Fi 6 support.
I also found a discussion of our problem here

[LAN latency] Can i force a VHT rate for a client or the entire radio?

[bruce]

Hi,

If possible, could you please try to downgrade the v4.6.2 firmware to test again if the issue clients speed normal, please let me know the results if you did.

[27leguas]

Thank Bruce for your advice!

Going back to v4.6.2 fixed all the issues

On v4.6.2 "Huawei Mate 20 Lite" is constantly hitting above 200Mbps up an down
and
The "Doogee T30 Ultra" tablet easily reaches 300Mbps up and down

As far as I've tested:
v4.6.2 - AC 5Ghz (80MHz) it's fine
v4.6.4 - not tested - Updated WiFi driver (MT3000)
v4.6.8 - AC 5Ghz (80MHz) is buggy
v4.7.0 - AC 5Ghz (80MHz) is buggy

Could the new WiFi Driver introduced in 4.6.4 be the culprit?

[27leguas]

On v4.6.2 downgraded firmware

On v4.6.8 (v4.7.0 has very similar results)

[bruce]

Hello,

Probably R&D find the issue reason, please try this improved test firmware on your MT6000, thank you.

openwrt-mt6000-20241221154531.zip

[27leguas]

The WiFi behavior of beta firmware you provided is as good as the v4.6.2.
I haven't found any of the problems present in the v4.6.8 and v4.7.0 releases.

Many thanks Bruce!

[raphamotta]

Great, it seems the same problem I was facing on firmware > 4.6.2.

MT6000 slows down 5Ghz connection after some time - Technical Support for Routers - GL.iNet

EDIT: Mine is also a Huawei smartphone (P30 Pro) and I faced a problem with Amazon Echo Show 5 (Android based)

Thanks Bruce.

[lecmipahu]

It would be great to know what was the problem and the fix, so that it could be potentitally also imported to the upstream OpenWRT.

[bruce]

@lecmipahu

imported to the upstream OpenWRT

Unlike OpenWrt open-source driver, this is the issue of MTK closed-source driver.
We have been sync to MTK.

[aheas]

Hi Bruce I tried to download this testing firmware but not available anymore . Link expired . Can you provide other link ? Thank you

[bruce]

Hello,

Did you have same issue about it on the MT6000?

What the ac client model is?

Updated the available time:

openwrt-mt6000-20241221154531.zip

[aheas]

Hi Bruce thank you for the testing file . I m having issue with 5ghz 80/160 buggy . 4.7.0 op21.