2.4 GHz WiFi Instability

[Elmer]

So, there was a sale on ac88s recently, so I moved on up. Great machine, running latest Merlin 384.4 firmware. Significant other kept complaining about connectivity issues. Did a wifi scan from another device, and the 2.4 GHz SSID was not there. Hmmm, I was using the smart connect feature, so I dumped that, and split the SSIDs to two different names. Few hours, and no 2.4 GHz SSID again. Saw the remarks about the airtime fairness and beam forming problems so I tried disabling them one at a time, waiting, waiting, waiting, but same behavior. Then I read that someone way back in 2015 had this issue on an ac68 and set 2.GHz bandwidth to 20 MHz (only) and it stabilized. I did this and, what do ya' know, it's been stable for a week now. According to this person it is an ASUS code problem (not Merlin) and it appears ASUS has their collective heads buried in the sand on the issue. Wondering if anyone else has seen this, or if possibly I've lost the hardware lottery, and just have a poor quality wifi TX system?

 

[scjr]

Don’t think it’s an Asus issue. I set mine to 20MHz, because that’s where it’s stable as well.

Check out Merlin’s WiFi tips here:

https://www.snbforums.com/threads/guide-troubleshooting-wifi-issues.12825/

Issues specific to 2.4 GHz:

The 2.4 GHz band is VERY crowded. You can get interference from a wide variety of devices:

• Microwave ovens
• Baby monitors
• Old cordless phones
• Bluetooth devices
• All your neighbour's routers

Due to this, you should set channel width to 20 MHz on that band. A 40 MHz connection would require you to overlap no less than 5 channels. Highly unlikely you will get a reliable 40 MHz connection in any urban area with so many channels overlapping. Yes, it will cut your maximum performance in half, but if you want a STABLE connection on the 2.4 GHz band, there is little you can do about this. Otherwise, the 5 GHz band is your only solution.

 

[Elmer]

Ah, okay. Now is there a way to set smart connect back on and retain the 20 Mhz only bandwidth? Seems to allow auto bandwidth only. Also, according to the orginal posting, the other solution is to go with Tomato or DD-WRT. If Tomato and DD-WRT do not have the same problem on the same hardware wouldn't that point toward a possible ASUS software issue?

 

[RMerlin]

If Tomato and DD-WRT do not have the same problem on the same hardware wouldn't that point toward a possible ASUS software issue?

Neither of these have Smart Connect.

 

[Elmer]

Neither of these have Smart Connect.

But the issue appears to be bandwidth control. The problem persisted with smart connect turned off. This morning my system dropped wifi again after about 7 days up using 20 Mhz bandwidth, so even the 20 MHz bandwidth bandage is just that. My new kludge fix is to set 2.4 GHz at 20 MHz bandwith and to do an auto reboot twice a week. Maybe that will work. Otherwise I'll have to turn off my $300 router wifi radio and go with an aternative AP.

 

[nzwayne]

But the issue appears to be bandwidth control. The problem persisted with smart connect turned off. This morning my system dropped wifi again after about 7 days up using 20 Mhz bandwidth, so even the 20 MHz bandwidth bandage is just that. My new kludge fix is to set 2.4 GHz at 20 MHz bandwidth and to do an auto reboot twice a week. Maybe that will work. Otherwise I'll have to turn off my $300 router wifi radio and go with an aternative AP.

I have two Epson printers that can be challenging to work on 2.4GHz, one more then the other as physically more distant through a couple of walls. What I've found to make them work reliability after much playing with settings and firmware levels is...
a). Airtime fairness - disabled
b). Universal Beamforming - disabled
Bandwidth can be 20MHz or 20/40MHz (AC87U or AC86U). Smart Connect enabled or disabled doesn't matter on the RT-AC86U.
After changing settings on the router, I noted "sometimes" had to connect the printers to another SSID and then back again to the SSID I want them to work on. Powering off/on Printers and Routers didn't help.

 

[dlandiss]

Maybe that will work. Otherwise I'll have to turn off my $300 router wifi radio and go with an aternative AP.

Or try different 2.4GHz channels.

 

[Elmer]

Or try different 2.4GHz channels.

I use the android "wifi analyzer" to set the best (least crowded) frequency since some posting seem to suggest you should never use auto frequency select. Interesting thing is, I'm using an old dlink 1200 router as a cheap AP sitting on another SSID with another frequency in an even a more crowded spectrum area and it's pretty darn solid. It's off in a far corner and handles an external camera and some "smart home" devices. When the Asus is working, the Asus 2.5 GHz 20 MHz signal nudges some nearby routers, that must be set on auto, to other channels. I did not notice any difference with airtime fairness and beamforming disabled, but I'll try that again in conjuction with the 20 MHz only signal.

 

[dlandiss]

"Crowded" is not as simple as it seems. Channels -2, -1, +1, and +2 with respect to yours should be considered also.

 

[sfx2000]

"Crowded" is not as simple as it seems. Channels -2, -1, +1, and +2 with respect to yours should be considered also.

2.4Ghz is not as big of a deal as many make it...

Might want to review here -- https://www.snbforums.com/threads/insight-from-google-fiber-wifi-performance.40149/

Links inside to back things up...

 

[Elmer]

2.4Ghz is not as big of a deal as many make it...

Might want to review here -- https://www.snbforums.com/threads/insight-from-google-fiber-wifi-performance.40149/

Links inside to back things up...

2.4 GHz is a big deal if you're trying to run a bunch of "smart home" devices that use it, and only it. Thanks for the link though; I'm turning air fairness back on after reading it. I agree with the post that universal (legacy) beam forming is mostly a gimmick, and that stays off.

My latest kludge was 2.4 GHz with 20 MHz bandwidth and a soft reboot (using the Admin menu) twice a week. Well, soft reboot is not a cure all. I have a hardwired device (dhcp) that emails me when it goes off line and comes back on again, and 1) that device went off line and would not come back on (6 hours later) until I did a router power recycle, 2) 2.4 GHz wifi didn't recover from the soft reboot. Again it took the router power recycle to get everything back to normal. So, moral of the story, be very careful with soft reboots - I sopped using that bandaid.