Asus XT8 - Wireless Backhaul - Capping at 350Mbps on 160MHz/5GHz

[jamesfromage123]

HI all,

I have recently just purchased a pair of Asus XT8's.

They are setup using the dedicated wireless backhaul on channel 116 in 160MHz mode and have been rock solid in terms of stability.

Via the web console it says the wireless backhaul connection speed of being around 3000 Mbps up/down yet when I run iperf tests between a device connected via Ethernet to the main/router and then a ethernet connected device on the 2nd node I will never get more than 350Mbps even with 2 Asus XT8's next to each other. I have confirmed they are connected via 160MHz and as mentioned in the web console the lowest I have seen the wireless backhaul connect at is still above 2000Mbps.

Any idea why I'm getting such poor wireless backhaul speeds ?

Thanks

 

[kildare]

even with 2 Asus XT8's next to each other

XT8 LAN ethernet ports are 1 Gbps, so even if the 2000 Mbps backhaul link should be fully effective (but it's actually impossible for a wireless connection), the limiting factor would be the ports.

As you can place the 2 XT8s near to each other, try connecting them with an ethernet cable and repeat the test to see if the speed increases.

 

[jamesfromage123]

So just for testing (as I need wireless backhaul with this setup) but using ethernet backhaul running the same tests I'm getting the expected 1GB (well 949Mbps).

Then disconnecting the ethernet between the nodes I get between 330-360Mbps again (even 1 meter apart), which is odd when it says the link between the nodes in the web console is over 3000Mbps, I would have expected to get a true 1GB at both ends plugged in via ethernet over wireless backhaul surely, or a load better than 300Mbps

 

[kildare]

Check if you have other 5 GHz wifi networks interfering with yours.

 

[jamesfromage123]

Also just for testing I connected a laptop to my backhaul ssid and I was able to get 500ish Mbps with a device that was only connecting at 1400Mbps

 

[jamesfromage123]

Check if you have other 5 GHz wifi networks interfering with yours.

No channel overlap at all with my backhaul channel, infact was surprised at the lack of other 5GHz wifi detected

 

[ColinTaylor]

What do you get if you connect your laptop the node's normal Wi-Fi (not backhaul) rather than using it's Ethernet port?

 

[jamesfromage123]

The same 300-350Mbps, so the limiting factor is the Wireless Backhaul (even though it says the connection is as fast as can be expected). If I connect to the node when the XT8's are connect via Ethernet Backhaul then I get around 500-600Mbps+

 

[ColinTaylor]

Have you tested using a simple SMB file transfer? I've found that using iperf over Wi-Fi can give misleading results if you don't specify certain parameters.

 

[jamesfromage123]

I haven't tried SMB transfer yet, but when I try a simple speedtest.net I get the same reduced speeds when connected to that node (when its on wireless backhaul)

 

[ColinTaylor]

Ok, not iperf-specific then.

 

[kildare]

They are setup using the dedicated wireless backhaul on channel 116 in 160MHz mode and have been rock solid in terms of stability.

Anyway, channel 116 apparently is not the best channel (see image) as it might be affected by weather surveillance doppler radars.
If there are no other wifi networks using the 5 GHz band, you could try setting 100 as the 5 GHz-2 channel.

 

[drinkingbird]

Anyway, channel 116 apparently is not the best channel (see image) as it might be affected by weather surveillance doppler radars.
If there are no other wifi networks using the 5 GHz band, you could try setting 100 as the 5 GHz-2 channel.

100 and 116 will both overlap weather radar on 160mhz as you can see in the pic. If it was detecting radar it would drop to something below 160 but I'd give the 36-64 range a try to see if it is better.

You may find you get better performance with 80mhz on a non DFS channel range.

 

[ColinTaylor]

He can't use channels 36-64 for backhaul on that model AFAIK. He could use 149/80 or 100/80 and see if they're any better.

 

[jamesfromage123]

I have tried 100/80 and still strangly get the same bandwidth limitation. I have had this setup for over a week so far and not had any radar events on DFS yet.

I will continue to play around and see if it improves, its been great otherwise (stable etc) and the only other issue I have seen is a "smart plug" show constantly as "offline" even when its not (via the app and webconsole.

My setup is an XT8 as the main router at the front of the house (where the fibre enters the building) and the a second XT8 node (which is connect via Wireless Backhaul) which is about 13 meters away in the kitchen. Then the XT8 node is connected to a RP-AX58 via Ethernet (30meters) in the garden room.

 

[ColinTaylor]

If you completely power off the RP-AX58 does that make a difference? I can't think why it would though.

 

[jamesfromage123]

If you completely power off the RP-AX58 does that make a difference? I can't think why it would though.

No difference at all, as I when testing in the garden room I have used the ethernet cable from it (with the AX58 turned off)

 

[glens]

I've got experience with XT8s, though I've never toyed with wireless "backhaul" between them. I use both 5 GHz radios in each for dedicated / discrete client connection.

That being said, I see absolutely no reason you shouldn't be able to net gigabit-class connectivity between the units using the 5-2 radios, if you can obtain low-restriction connectivity, using either DFS /or/ UNII-4 if either are available in your locale.

See if you can enable UNII-4 and set the control channel to 153 for the backhaul. It'll end up near 6 GHz, so obstacle penetration won't be as great as with channel 100, say. But there will NEVER be DFS problems there, and quite likely you'll be the only one within "earshot" using that spectrum.

 

[jamesfromage123]

Just an update for anyone interested, I think I have resolved the issue and that was by manually setting the backhaul channel to 160MHz rather than letting it automatically decide.

What was odd though when testing with it set to auto in wifi-analyser etc it would also show it as 160MHz but was only ever getting 300-400Mbbps between nodes (even though the web console etc would show 2000-3000Mbps), now I'm getting a solid 1Gbps.

 

[ronan_zj]

Just an update for anyone interested, I think I have resolved the issue and that was by manually setting the backhaul channel to 160MHz rather than letting it automatically decide.

What was odd though when testing with it set to auto in wifi-analyser etc it would also show it as 160MHz but was only ever getting 300-400Mbbps between nodes (even though the web console etc would show 2000-3000Mbps), now I'm getting a solid 1Gbps.

yes, I did the same way. when I set channel bandwidth to 160Mhz and channel 173, I got solid connection.