RT-AX92U AiMesh connection slows over time

[MBD]

Hello!

Here's a topology diagram of my home network:

I have a gigabit fiber connection.

As you can see, I have one RT-AX92U connected directly to the ONT as a router and another one upstairs in my office as an AiMesh node via the 5GHz-2 backhaul.

I did the basic setup for both via the app, then updated the firmware. Both are running firmware 3.0.0.4.386_45898 and I hard reset them (WPS) after updating.

Connected via ethernet to the AiMesh node are my PC and my work laptop. All other devices connect wirelessly to whichever router they please.

The issue is that, over some amount of time (usually a few hours, sometimes longer), the 5GHz-2 backhaul connection to the AiMesh node seems to slow until I restart the node. It starts out at 850-1000 Mbps delivered to my wired devices and slows to 300-600 Mbps.

My network is configured this way because I would like close to gigabit speeds upstairs in my office, but running a cable is infeasible, as I live in an apartment and don't want to tape a wire all across my kitchen ceiling, up the stairs, into my office.

Let me know what more information I can provide to troubleshoot this!

Thanks a ton in advance.

 

[L&LD]

Welcome to the forums @MBD.

How are you testing these speeds? What kind of connection speeds do you get to the main router (wirelessly, when the node is off)?

Can you test different cables? If you don't have any handy, test by flipping them around between the desktop/laptop and router. Try also different ports if you can.

Test different Control Channels, test moving either/both the routers (even minimally), test different orientations of the router(s) and antennae too.

Finally, from the main router's GUI, remove the node and then fully reset it again with the appropriate WPS Button reset method for your router before re-associating it again (also, and particularly, if you change the Control channels above).

[Wireless] ASUS router Hard Factory Reset | Official Support | ASUS Global

 

[MBD]

Welcome to the forums @MBD.

Thanks!

How are you testing these speeds? What kind of connection speeds do you get to the main router (wirelessly, when the node is off)?

Speedtest.net, fast.com, and downloading files via Steam. I get 300-450 Mbps on my WiFi 5 clients (I do not have any WiFi 6 devices currently, so I can't really test the ax connection).

Can you test different cables? If you don't have any handy, test by flipping them around between the desktop/laptop and router. Try also different ports if you can.

Test different Control Channels, test moving either/both the routers (even minimally), test different orientations of the router(s) and antennae too.

Finally, from the main router's GUI, remove the node and then fully reset it again with the appropriate WPS Button reset method for your router before re-associating it again (also, and particularly, if you change the Control channels above).

Given how long the issue sometimes takes to appear, testing all of this will take some time with proper independent variable control, but I will try these over the next few days.

In the mean time, if this issue smells familiar to anyone and there's anything else I can check, let me know!

Thanks.

 

[L&LD]

Downloading files from Steam isn't a good measure of your wireless (the highly intensive variable is Steam itself).

At 300-450Mbps, you're getting what is expected.

 

[MBD]

Downloading files from Steam isn't a good measure of your wireless (the highly intensive variable is Steam itself).

At 300-450Mbps, you're getting what is expected.

Yes, I would expect 300-450 Mbps over WiFi 5; no question, that is what is expected.

With the AX backhaul to the AiMesh node, however, I would expect 950ish Mbps to the node (and thus to devices wired to it), which is what I get most of the time.

There is some reason it drops randomly and requires restarting the node to get back in line. That is what I am here to try to figure out.

Thanks!

 

[le_communiste]

Check in your main router: Advanced Settings -> System Log -> Wireless Log
To see the current connection speed and current connection channels between Router and Mesh
Are the speeds indicated or the connection between Router and Mesh changing over time?

To exclude external influences I would recommend the following testing scenario approach:
Connect a PC to your main router via LAN and connect a 2nd computer via LAN to your Mesh Router and then use a tool like LanBench to measure performance.
You could also perform this test via WLAN if you make sure the 1st pc is connected to main router and 2nd to the Mesh router.
The more you reduce external influences like WLAN, WAN or other the easier you will be able to point to what is likely the cause of the poor performance. Good Luck testing.

 

[WeirdG]

I recently purchased the AX92U 2-pack and was reluctant to keep it, but it's performing well beyond expectations. I suspect the October 2021 firmware fixed most of the big issues people were experiencing. Between two floors, this is what my connection looks like over the 5GHz-2 wireless backhaul. The router is connected in a corner on the second floor, and the AiMesh node is connected in the opposite corner of the house on the first (main) floor.

These are my 5GHz-2 wireless settings.

In general, I find hard coding certain values gives the best results with wireless routers (e.g. Wireless Mode, Control Channel, Channel Bandwidth, etc). Auto is not always the best option.

I'm actually considering to use the AiMesh node with a Powerline adapter, since I have a couple of gig adapters laying around.

 

[leerees]

If your backhaul is slowing over time, you need to experiment with placement of the node so you get a better connection. WiFi signals bounce around so it's not always obvious where to place the node.

If you enable client access on the backhaul, your AX devices should also receive the full 1gbps. An easy way to set this up is to initially configure it in tri band mode with a wired backbaul. Then, once you are done, remove the ethernet cable and it will fall back into wireless backhaul mode but with shared client access on the AX band.

If it's still not fast enough, check the 5ghz2 band is using 160mhz DFS channels. It should give you >2gbps if setup correctly. If you are in a radar sensitive area it shouldn't matter as everything will be automatically shifted to the AC band when needed. Experimemt by manually selecting the AX control channel until it connects at 160mhz (make sure you select 160mhz from the drop down menu). For me, selecting channel 100 got it working in 160mhz.

For AC devices, 450 mb/s is to be expected. Unfortunately, the AC radio is only 2x2. The work around is to enable clients to share access with the stronger 4x4 AX backhaul channel.