Simple tip to improve AiMesh performance (RT-AX68U + RT-AC86U)

[SimoniZ]

I have used for a while the RT-AC86U as my main router and the RT-AC68U as a wireless repeater. The first version of AiMesh did not support the USB function on connected mesh nodes, so I ended up keeping my RT-AC68U in repeater mode in order to keep using it as a file server. AiMesh 2.0 added USB function to mesh nodes and this was the main feature that I was waiting for ASUS to add.

Currently my setup is now using the RT-AX68U as my main router and the RT-AC86U as a mesh node. Although I found the wireless performance improved in mesh mode in comparison to repeater mode, my network was very unstable. Typically I would need to reboot both routers about once a day in order to temporaily resolve network disconnects, unresponsiveness, and poor throughput (something that would degrade the longer the routers were up). Logging into the main router, the management page would be extremely unresponsive even though the CPU utiliztion on both cores were between 0-2%.

It didn't matter what settings I changed or disabled on my main router, nothing helped the issues that I was observing. RT-AX68U is in a good location, but my RT-AC86U was inside of a entertainment unit. In order to resolve the issues I was expericing, all I did was move the RT-AC86U onto the top of my entertainment unit. Once I made this change, literally a 10inch different in placement, everything in my network improved.

I think all of my issues have been due to poor connectivity between both routers, and this was enough to cause all sorts of issues. I did run some iPerf3 tests (in just one direction though) in order to show the improvements that were noticed.

*****************************************************
Had to reboot both routers before running tests 1 and 2 due to the previous poor connectivity between RT-AX68U <-> RT-AC86U.

Test #1 - RT-AC86U in the previous (BAD) location
-------
Server: PC
Client: IPAD AIR 4 <-> RT-AC86U (Mesh Node)

Results:
--------
avg: 293 Mbps
min: 129 Mbps
max: 341 Mbps

Test #2 - RT-AC86U in the previous (BAD) location
-------
Server: PC
Client: IPAD AIR 4 <-> RT-AX68U (Main Router)

Results:
--------
avg: 429 Mbps
min: 69 Mbps
max: 601 Mbps

*****************************************************

Test #3 - RT-AC86U in new (GOOD) location
-------
Server: PC
Client: IPAD AIR 4 <-> RT-AC86U (Mesh Node)

Results:
--------
avg: 322 Mbps
min: 249 Mbps
max: 356 Mbps

Test #4 - RT-AC86U in new (GOOD) location
-------
Server: PC
Client: IPAD AIR 4 <-> RT-AX68U (Main Router)

Results:
--------
avg: 504 Mbps
min: 150 Mbps
max: 584 Mbps

*****************************************************

The main thing to keep an eye on is the min and avg throughput results, both of which improved whether a client connected to the mesh node or the main router. Network connectivity issues have been resolved and the network is significantly more stable. I may run into some issues from time to time, but moving my mesh node by just 10in made such a big difference. Now in the new location my RT-AC86U is no longer being blocked on either side, or from behind.

Sorry for the long post, but the moral of the story is the issues many people are observing (disconnects, unresponsiveness, etc.) when using AiMesh mode could be due to bad placement of the mesh nodes or main router. Moving my RT-AC86U fixed all of my issues, not disabling or changing settings. This is just my experience and other networks can of course have different issues. Try moving your routers if possible to a new location and also try to place them as high as possible.

 

[Rocketboy235]

Your anecdotal experience makes sense. l ran into many issues with AiMesh earlier with 2 AC68U nodes and the primary router being AC68U (not the best setup but I had to make do... waiting for the AC86U to get a bit cheaper first). If the connection between the node and primary router isn't good and loses connection, then all devices attached to the node are just going to have a bad day.

I kind of gave up with the wireless route and just did an ethernet backhaul and basically resolved almost every issue I had earlier (not surprisingly). Only issue is I had to do a bit of work laying the ethernet cable and doing some drilling since the router and node aren't in the same building but relatively close.

 

[SimoniZ]

I am considering using a ethernet backhaul as well, just a little bit lazy and do not want to run a 50+ foot cable to connect to the two routers, but likely that setup would acheive even better results. Also all of my testing were done using 5 GHz.

 

[OzarkEdge]

I have used for a while the RT-AC86U as my main router and the RT-AC68U as a wireless repeater. The first version of AiMesh did not support the USB function on connected mesh nodes, so I ended up keeping my RT-AC68U in repeater mode in order to keep using it as a file server. AiMesh 2.0 added USB function to mesh nodes and this was the main feature that I was waiting for ASUS to add.

Currently my setup is now using the RT-AX68U as my main router and the RT-AC86U as a mesh node. Although I found the wireless performance improved in mesh mode in comparison to repeater mode, my network was very unstable. Typically I would need to reboot both routers about once a day in order to temporaily resolve network disconnects, unresponsiveness, and poor throughput (something that would degrade the longer the routers were up). Logging into the main router, the management page would be extremely unresponsive even though the CPU utiliztion on both cores were between 0-2%.

It didn't matter what settings I changed or disabled on my main router, nothing helped the issues that I was observing. RT-AX68U is in a good location, but my RT-AC86U was inside of a entertainment unit. In order to resolve the issues I was expericing, all I did was move the RT-AC86U onto the top of my entertainment unit. Once I made this change, literally a 10inch different in placement, everything in my network improved.

I think all of my issues have been due to poor connectivity between both routers, and this was enough to cause all sorts of issues. I did run some iPerf3 tests (in just one direction though) in order to show the improvements that were noticed.

*****************************************************
Had to reboot both routers before running tests 1 and 2 due to the previous poor connectivity between RT-AX68U <-> RT-AC86U.

Test #1 - RT-AC86U in the previous (BAD) location
-------
Server: PC
Client: IPAD AIR 4 <-> RT-AC86U (Mesh Node)

Results:
--------
avg: 293 Mbps
min: 129 Mbps
max: 341 Mbps

Test #2 - RT-AC86U in the previous (BAD) location
-------
Server: PC
Client: IPAD AIR 4 <-> RT-AX68U (Main Router)

Results:
--------
avg: 429 Mbps
min: 69 Mbps
max: 601 Mbps

*****************************************************

Test #3 - RT-AC86U in new (GOOD) location
-------
Server: PC
Client: IPAD AIR 4 <-> RT-AC86U (Mesh Node)

Results:
--------
avg: 322 Mbps
min: 249 Mbps
max: 356 Mbps

Test #4 - RT-AC86U in new (GOOD) location
-------
Server: PC
Client: IPAD AIR 4 <-> RT-AX68U (Main Router)

Results:
--------
avg: 504 Mbps
min: 150 Mbps
max: 584 Mbps

*****************************************************

The main thing to keep an eye on is the min and avg throughput results, both of which improved whether a client connected to the mesh node or the main router. Network connectivity issues have been resolved and the network is significantly more stable. I may run into some issues from time to time, but moving my mesh node by just 10in made such a big difference. Now in the new location my RT-AC86U is no longer being blocked on either side, or from behind.

Sorry for the long post, but the moral of the story is the issues many people are observing (disconnects, unresponsiveness, etc.) when using AiMesh mode could be due to bad placement of the mesh nodes or main router. Moving my RT-AC86U fixed all of my issues, not disabling or changing settings. This is just my experience and other networks can of course have different issues. Try moving your routers if possible to a new location and also try to place them as high as possible.

Another way of stating this is to locate your antennas central, high, and in the clear (not buried low in a box with other electronics). Of course, with two or more nodes you must moderate the meaning of central.

Another consideration... the AC86U has about 20% better WiFi coverage than the AC68, so you need to distance them according to the lessor range of the AC68U.

Finally, I would keep the stronger AC86U as the router, but I suspect you have a reason for relegating it to AP duty.

OE

 

[SimoniZ]

RT-AC68U was my wifi repeater, I recently purchased the RT-AX68U which replaced my RT-AC86U as my main router (changed was done once I switched from repeater mode to AiMesh mode). Interesting thing to note is that the AX68U and the AC86U share the same CPU, memory, and storage size.

I do like your more condensed explanation, mine is little long.

 

[OzarkEdge]

RT-AC68U was my wifi repeater, I recently purchased the RT-AX68U which replaced my RT-AC86U as my main router (changed was done once I switched from repeater mode to AiMesh mode). Interesting thing to note is that the AX68U and the AC86U share the same CPU, memory, and storage size.

I do like your more condensed explanation, mine is little long.

Ah, sometimes I read those model numbers and don't see what I'm looking at!

OE

 

[SimoniZ]

After overcoming my laziness, I decided to take the time and neatly route a 75ft flat Cat7 ethernet cable from my RT-AC86U (WAN Port) -> RT-AX68U (SW Port 1), which took me about 5 hours. The difference when using an ethernet backhaul is night and day. No more wireless disconnects, and the overall improvements to responsiveness/stability of the wireless network is just amazing.

Reminds me when I use to work for a data centre as a network analyst and one of the network engineers would tell me how he could just log into one of the core switches or routers and just feel if the network was running well, or if there was some sort of issue. Overall feel of my network is finally where I wanted it to be for over 3-4 years.

Transferring files to or from my 7 connected USB drives that connect via Apanage 8 Port Powered USB 3.0 Hub -> RT-AC86U (USB 3.0 port) now yields around 70-80 MB/s, while before using a wireless backhaul (Dual Band) I was getting about 45-55 MB/s.

I will continue to test but hopefully this new found network stability and performance is here to stay!

 

[leerees]

I will concur that disconnection issues are caused by poor internode connectivity.

Check the RSSI levels of each node.
The RSSI level should be -60 or better (-50 is better than -60).

 

[leerees]

After overcoming my laziness, I decided to take the time and neatly route a 75ft flat Cat7 ethernet cable from my RT-AC86U (WAN Port) -> RT-AX68U (SW Port 1), which took me about 5 hours. The difference when using an ethernet backhaul is night and day. No more wireless disconnects, and the overall improvements to responsiveness/stability of the wireless network is just amazing.

Reminds me when I use to work for a data centre as a network analyst and one of the network engineers would tell me how he could just log into one of the core switches or routers and just feel if the network was running well, or if there was some sort of issue. Overall feel of my network is finally where I wanted it to be for over 3-4 years.

Transferring files to or from my 7 connected USB drives that connect via Apanage 8 Port Powered USB 3.0 Hub -> RT-AC86U (USB 3.0 port) now yields around 70-80 MB/s, while before using a wireless backhaul (Dual Band) I was getting about 45-55 MB/s.

I will continue to test but hopefully this new found network stability and performance is here to stay!

If you use 160Mhz channels you will get 950 mb/s (117 MB/s)

 

[SimoniZ]

Although a channel width of 160MHz increases available bandwidth and therefore "may" increase throughput in some cases (assuming client support, interference, and distance isn't an issue), it doesn't apply to my situation for two reasons.

1. RT-AC86U which I use as a mesh node and file server does not support 160MHz channel width
2. Many Asus routers do not fully support all features of Wi-Fi 6 (not Wi-Fi 6 Certified), one of those routers is the RT-AX68U which also does not support 160MHz channel width.

I would of course try 160MHz channel width if the option was available to me, but it isn't on either of my routers. Why Asus decided to remove support for 160MHz from RT-AX68U is something that doesn't make much sense to me.

 

[Tech9]

Why Asus decided to remove support for 160MHz from RT-AX68U is something that doesn't make much sense to me.

Perhaps the same reason why your RT-AC86U doesn't have 160MHz. The RGB version GT-AC2900 does.