AC87U - Mobile (WiFi) connectivity crippled at random, can affect wired devices on 2.4G

[DAOWAce]

I've been having a bizarre issue with my network over the last year that no amount of troubleshooting has seemed to resolve.

To summarize: Every so often the wifi connection will severely degrade. Speeds will drop to 1-10mbit (from 200) and the connection will start hanging.

The problem can either be resolved by toggling wifi on the device, rebooting the device, rebooting the router, or waiting an indeterminate amount of time (~20 minutes?) for the problem to 'clear up'. Toggling wifi on the device is the fastest solution, however it doesn't always work, sometimes the problem is still there but less severe (30-40mbit speed, mild hanging), but rebooting it restores fully normal operation without fail.
--
EDIT: Just had an instance where the connectivity was garbage after leaving my tablet on overnight. Toggling wireless or restarting the device DID NOT WORK. It improved slightly as mentioned above, but no matter what I did, nothing resolved it. I had to reboot the router this time.

Meanwhile, wired devices were just fine.
--

To make matters even more bizarre, when using 2.4GHz, this affects the router itself, bogging down all connections, wired or wireless. Ping times shot through the roof (delayed even pinging the router) and speeds slowed to a crawl on all devices, be it a $5000 gaming machine or $100 tablet.

After failing to resolve it, I opted to just disable the 2.4GHz band, leaving everything in 5GHz.

I've been browsing threads and google results over the last 2 months, trying many many different configurations, but none have ever resolved it.

Channel ID doesn't matter.
Channel width doesn't matter.
WMM No-Ack on/off doesn't matter.
Multi-User MIMO on/off doesn't matter.
Beamforming on/off doesn't matter.
IGMP Snooping on/off doesn't matter.
DTIM Interval doesn't seem to matter (low testing).
Beacon Interval doesn't seem to matter (low testing).

The wireless is WPA2 secured, if that matters. Has unique SSIDs for both bands.

There's various other non-wireless related settings I've dabbled with, but I don't think they're relevant. Just ask if you need to know anything else.


Problem existed on stock ASUS firmware. I upgraded to Merlin hoping for a change, but no change. It's been through a year of firmware updates now, and again, no change to the issue.

Temperature of CPU right now is 70°C. 5GHz is 55°C. Seems normal to me.

As for setup in the house, we used to have it connected to hub in the attic routing to different rooms, then a WD N900 acting as an AP (and storage device) on the opposite side of the house. Eventually replaced it, and the hub, with a UniFi AC Pro.

Truth be told, besides the 2.4G issue, it didn't affect me otherwise as I never had a mobile device. My family would complain at times that the internet was slow and I was "throttling their connection", I always just assumed it was sites they were visiting. Now I own a mobile device (tablet and phone for christmas, yay), and I use the tablet regularly for media consumption/gaming away from my PC, and the issue is affecting me practically every single day now, sometimes multiple times a day.

Besides getting a new router (reading this forum has shown me there's been a lot of issues with ASUS routers and wireless bands), which I don't want to do (this was $250 and works fine otherwise), I'm clueless as to how to fix this problem.

 

[Grisu]

Thats exactly why I sold all my Asus routers.
You can try load Merlin which is usually more stable than stock and factory reset with initialize (dont reload saved config).
Repeat these steps with final factory reset.
Use fix channels 2G and 5G and disable airtime fairness and universal beamforming.

 

[AndreiV]

RT-AC87U .........

You either get a good one or a total disaster and the bad ones won't be cured by anything so it's better for your health to find an alternative router.

They use Quantenna WiFi drivers and they are known to be beyond bad, they caused problems from day one on this model.

I had 4x 87U's, one after the other , changed under warranty until the supplier said they wouldn't supply them any more, and offered a full refund or an upgrade to a different model.

Synology have two excellent AC class routers that will do what you want.

 

[DAOWAce]

So the short consensus is it's probably the router and its hardware and no amount of configuration changes will do anything.

I don't have the cash to afford replacing this high-end router after holiday shopping and my own PC upgrade (3950x, ouch), nor do I pay attention to networking hardware to know what's good or bad, so I consider it a last resort. If anyone has any updated (2019) router buying guides they could link, then it would help me in future, but as of right now I'm stuck with what I have.

You can try load Merlin
Use fix channels 2G and 5G and disable airtime fairness and universal beamforming.

I've done all this; nothing resolved the issue.