XT9 AiMesh roaming trouble

[jaymizl]

Just about at my wit's end trying to figure this out: I Have a pair of XT9's connected via wired backhaul AiMesh at opposite ends of the house (1 downstairs + 1 up 2 flights of stairs.) and am utilising the 5GHz-2 band to connect my wireless device (macbook pro) as that is what is giving me the most stable/fastest speeds.

The problem is the macbook doesn't seem to want to roam between the currently connected node and main router and visa-versa. I must always manually reconnect in order to get it to switch. I have read up about Macs being rather sticky and OSX not searching for a new access point until the current connection hits an RSSI threshold of -75dBm. Well I am sitting here with between -80 and -83 dBm connected to the main router downstairs and it still will not switch to the node upstairs which is right next to me with -30ish RSSI. The main router and node could not be further apart as they are.

Roaming seems to work pretty well from what I can tell when utilising the 2.4GHz and 5GHz-1 bands at the cost of decreased stability/speed performance. Not ideal.

On the 5GHz-2 band I have:

Adjusted roaming assistant to varying values from -40 to -70
Disabled Roaming assistant completely
Diasabled Universal beamforming
Adjusted tx power levels all the way through from Performance down to power saving
Tested a variety of different bandwith and control channel settings.

I simply cannot seem to get it to roam correctly. Any help or advice?

 

[Tech9]

Any help or advice?

There is information online how to change RSSI threshold level in macOS, but I don't know how comfortable you are doing it. What you can do on the AP side is change the minimum data rate. This will reduce the effective range. On Asus routers the setting is in Wireless, Professional - Multicast Rate. I don't know if it works on your hardware and firmware though. I found many settings just doing nothing on different Asus routers and different firmware. You already found Roaming Assistant doing nothing. Test and see what happens before you eventually proceed playing with macOS settings.

 

[jaymizl]

Thanks will give that a go!

Certainly not a networking expert, but with a bit of research and a detailed enough guide, I'm comfortable tinkering around. All research I've done has led me to believe that it isn't possible to change the macOS threshold, however. Will dig further down the rabbit hole, but any chance you could point me in the right direction?

 

[Tech9]

down to power saving

By the way, this will cut the radio power down, but also the performance to single stream Tx/Rx. Not a good option.

but any chance you could point me in the right direction?

I've never done it myself and what I find is CLI commands. I would rather leave the macOS alone at default settings. You perhaps use this computer outside of your network as well. What may work better inside your home may also create a problem outside of your home. This is a mobile device.

 

[Tech9]

wired backhaul AiMesh

If you don't use Guest Network to node feature - break AiMesh* and use the second router in AP Mode instead. It will open Control Channel and Tx power individual per AP options. This way you have more tools in your hands to fine tune your system and also a good chance for higher aggregate throughput to your wireless devices connected to different APs. If this is practical for you though - I don't know. It depends on what region you live in and what available Wi-Fi channels you have there.

* - there is a trick how to do it on paired "mesh" sets, if you are interested.

 

[jaymizl]

By the way, this will cut the radio power down, but also the performance to single stream Tx/Rx. Not a good option.



I've never done it myself and what I find is CLI commands. I would rather leave the macOS alone at default settings. You perhaps use this computer outside of your network as well. What may work better inside your home may also create a problem outside of your home. This is a mobile device.

Understood.

Is the "Fair" setting okay or is "Balanced" recommended?

Have tested lower multicast rates of OFDM 24 and OFDM 12. Neither seemed to help at all. I have no idea what gives when the other bands work completely fine.

 

[jaymizl]

If you don't use Guest Network to node feature - break AiMesh* and use the second router in AP Mode instead. It will open Control Channel and Tx power individual per AP options. This way you have more tools in your hands to fine tune your system and also a good chance for higher aggregate throughput to your wireless devices connected to different APs. If this is practical for you though - I don't know. It depends on what region you live in and what available Wi-Fi channels you have there.

* - there is a trick how to do it on paired "mesh" sets, if you are interested.

This is actually one option I was thinking to try, but considered wether it would actually make any difference? And what benefit would I lose out on by not using AiMesh?

I would have to factory reset the node and set it up as an AP, while the main router is turned off, correct?

FWIW I live in UK so would have access to whatever those channels are.

 

[Tech9]

Is the "Fair" setting okay or is "Balanced" recommended?
Have tested lower multicast rates of OFDM 24 and OFDM 12. Neither seemed to help at all.

I'm not sure changing Tx power setting on the main unit does anything on the node as well. Most people have their routers on default Performance. In theory Roaming Assistant and Multicast Rate may help in your situation, but as I said Asuswrt firmware reality is often different than expectations.

And what benefit would I lose out on by not using AiMesh?

No Guest Network to node propagation, no central "management" screen (useless anyway). All the rest are AP Mode benefits. You have own GUI per AP with own settings. Your wired AiMesh node is in fact an AP with a fancy name. Roaming is the same (client managed). Yes, node in AP Mode first is correct.

 

[jaymizl]

I'm not sure changing Tx power setting on the main unit does anything on the node as well. Most people have their routers on default Performance. In theory Roaming Assistant and Multicast Rate may help in your situation, but as I said Asuswrt firmware reality is often different than expectations.



No Guest Network to node propagation, no central "management" screen (useless anyway). All the rest are AP Mode benefits. You have own GUI per AP with own settings. Your wired AiMesh node is in fact an AP with a fancy name. Roaming is the same (client managed). Yes, node in AP Mode first is correct.

Hmm. Well, thanks for the assistance!

Will give AP mode a shot and report back

 

[jaymizl]

So had a bit of time to setup the node in AP mode and do some more testing.

I have managed to get the roaming on the 5GHz-2 band working somewhat reliably. The catch is...it required me to set both units to Tx power "power saving" and "OFDM 6" Multicast rate...

Are the downsides to running these setting so major?

 

[Tech9]

On all Asus routers I had in my hands Power Saving was restricting the radio to single spatial stream. This is a HUGE performance impact. For most 2-stream clients this means up to 50% of possible throughput. Try Balance instead and play with Roaming Assistant. It may be working in standalone mode, who knows.

 

[jaymizl]

On all Asus routers I had in my hands Power Saving was restricting the radio to single spatial stream. This is a HUGE performance impact. For most 2-stream clients this means up to 50% of possible throughput. Try Balance and play with Roaming Assistant.

Apologies, I'm still learning. For someone on the lower end of the technical know-how, could you explain what that might mean exactly? How that would effect particular tasks or usage? Running speedtests show top speeds still, but I'm sure you'll tell me there's more to it than that.

I'll give it a try, but from my experience Roaming Assistant does absolutely sweet nothing. Seems Macs are extremely stubborn about their roaming behaviour.

 

[Tech9]

could you explain what that might mean exactly?

This means the router will use single stream (single antenna, your 5GHz-2 radio has four streams and four antennas) for communication to wireless clients with link speed up to 433Mbps (AC) and 600Mbps (AX) with throughput around 60% in real conditions. If your Internet connection speed is slower you may notice no difference in speed tests (device to Internet), but your entire internal network will be limited as well (device to device). You also lose range (may be important), Beamforming and MU-MIMO capabilities (not really important). Keep in mind the throughput numbers are limiting the entire wireless network - throughput to all devices combined, not to single device only.

Not sure if it's more clear, but you cut the performance of the entire network to half of what it can do in most real life conditions. Perhaps not worth it for a single client.

 

[jaymizl]

As expected, setting the tx power to "Balanced" and using Roaming Assistant does not work. Macbook will not roam on 5GHz-2 with these settings

 

[Tech9]

In this case your only option left is to play with macOS settings, but you have to do your own research and accept the associated risk.

I wouldn't restrict the performance of the entire network because of one single client with roaming issues. You may have to live with what you get.

 

[jaymizl]

In this case your only option left is to play with macOS settings, but you have to do your own research and accept the associated risk.

I wouldn't restrict the performance of the entire network because of one single client with roaming issues. You may have to live with what you get.

I stumbled into some mac terminal commands that supposedly changed the wifi join preferences which didn't seem to help either.

Im truly stumped. Maybe time to re-evaluate.

In theory, would I have been better off with a pair XT8's? Seeing as they are said to have a lesser coverage/range. Perhaps I would have better luck roaming between a pair of those with my setup?

Or is that unlikely?

 

[Tech9]

Seeing as they are said to have a lesser coverage/range.

No, XT8 is about the same product as your XT9. In real life they perhaps perform exactly the same. I'm out of ideas here, someone else may try to help you further.

 

[jaymizl]

Thank you so much for lending a hand!

 

[Tech9]

If your client device sees and holds the AP on the opposite side of the house - one centrally located router is your solution. You perhaps don't need AiMesh.

 

[jaymizl]

You perhaps are right. The issue is I don't have ethernet access to the middle floor of the house, so setting up the router there would be more hassle than I'm willing to go through.

As mentioned, 2.4ghz + 5ghz-1 roam completely fine. Maybe a case of disabling the 5ghz-2 band altogether and sticking with 5ghz-1 albeit at slightly slower speeds