2.4Ghz WiFi on a RT-AC86U - what are the optimal settings?

[Woody]

If I said to you that I am running an RT-AC86U in a detached house with not very thick stone walls, in an area with approx another 10 2.4Ghz networks visible from my neighbours, but very few of them on Ch11 (which I have set). This is a mixed network of 2 - 3 laptops and two smart phones (connecting at 5Ghz) and approx 30 other (mainly IOT Tasmota ESP) devices connecting on 2.4Ghz AND quite a lot of BT traffic for about 10 Xiaomi room temp sensors (all chatting to Home Assistant).

What would you suggest that I change in my current settings below?

I ask, because while a see a number of forum posts focused on certain settings, I don't think I have ever seen a conclusive best practice post that covers all 2.4Ghz settings in one.

Thanks!

Band	2.4 GHz
Enable Radio	Yes
Enable wireless scheduler	No
Set AP Isolated	No
Roaming assistant	Disable
Bluetooth Coexistence	Disable
Enable IGMP Snooping	Disable
Multicast Rate(Mbps)	Auto
Preamble Type	Long Short
AMPDU RTS	Enable Disable
RTS Threshold	2347
DTIM Interval	3
Beacon Interval	100
Enable TX Bursting	Enable
Enable WMM	Enable
Enable WMM No-Acknowledgement	Disable
Enable WMM APSD	Enable
Optimize AMPDU aggregation	Disable
Modulation Scheme	Up to MCS 11 (NitroQAM/1024-QAM)
Airtime Fairness	Disable
Multi-User MIMO	Disable
Explicit Beamforming	Enable
Universal Beamforming	Enable
Tx power adjustment	Performance

 

[OzarkEdge]

If I said to you that I am running an RT-AC86U in a detached house with not very thick stone walls, in an area with approx another 10 2.4Ghz networks visible from my neighbours, but very few of them on Ch11 (which I have set). This is a mixed network of 2 - 3 laptops and two smart phones (connecting at 5Ghz) and approx 30 other (mainly IOT Tasmota ESP) devices connecting on 2.4Ghz AND quite a lot of BT traffic for about 10 Xiaomi room temp sensors (all chatting to Home Assistant).

What would you suggest that I change in my current settings below?

I ask, because while a see a number of forum posts focused on certain settings, I don't think I have ever seen a conclusive best practice post that covers all 2.4Ghz settings in one.

Thanks!

​

Band	2.4 GHz
Enable Radio	Yes
Enable wireless scheduler	No
Set AP Isolated	No
Roaming assistant	Disable
Bluetooth Coexistence	Disable
Enable IGMP Snooping	Disable
Multicast Rate(Mbps)	Auto
Preamble Type	Long Short
AMPDU RTS	Enable Disable
RTS Threshold	2347
DTIM Interval	3
Beacon Interval	100
Enable TX Bursting	Enable
Enable WMM	Enable
Enable WMM No-Acknowledgement	Disable
Enable WMM APSD	Enable
Optimize AMPDU aggregation	Disable
Modulation Scheme	Up to MCS 11 (NitroQAM/1024-QAM)
Airtime Fairness	Disable
Multi-User MIMO	Disable
Explicit Beamforming	Enable
Universal Beamforming	Enable
Tx power adjustment	Performance

My configuration is posted here (it's brief to fit in one post, but the product of lurking here since 2018... since AiMesh 0.0). My 2.4 settings are mostly default except for the few changes noted... using ch 11 at 20MHz.

Some will suggest dumbing down the 2.4 WLAN for compatibility... if clients are happy, I leave it WiFi6 capable as shipped... I'm more inclined to retire early a troublesome client than dumb down the entire network.

OE

 

[bbunge]

Your best bet is to use the WIFI defaults including Dual Band SmartConnect. Yes, use auto channel and auto bandwidth and let the router and clients choose what is best. Your router is smarter than you are when it comes to WIFI.

 

[Woody]

My apologies - as I don't know what the defaults are (so can't revert to them) - I can only see what I posted (which is probably as a result of some tinkering long forgotten..)

I am using CH 11 at 20Mhz, but I don't set auto-channel, as I have it on 11 (to minimise interference - but it would probably select CH 11 on auto anyway).

I haven't enabled Smart Connect - because I have so many 2.4Ghz WiFi devices - that I didn't want stuff bouncing between networks and similarly, wanted to keep two discrete SIDD's - so that I could tell which was 2.4 and 5 (this is not a WiFi 6 router and there is no AI Meshing).

I realised, that I had left this page out - so for completeness..

Which, if any of these settings would you change - to what - and why?

Thanks!

Enable Smart Connect	OFF
Band	2.4 GHz
Network Name (SSID)
Hide SSID	No
Wireless Mode	Auto AND b/g Protection
Channel bandwidth	20Mhz
Control Channel	11
Authentication Method	WPA2-Personal
WPA Encryption	AES
WPA Pre-Shared Key	Strong
Protected Management Frames	Disable
Group Key Rotation Interval	3600

 

[OzarkEdge]

My apologies - as I don't know what the defaults are (so can't revert to them) - I can only see what I posted (which is probably as a result of some tinkering long forgotten..)

I am using CH 11 at 20Mhz, but I don't set auto-channel, as I have it on 11 (to minimise interference - but it would probably select CH 11 on auto anyway).

I haven't enabled Smart Connect - because I have so many 2.4Ghz WiFi devices - that I didn't want stuff bouncing between networks and similarly, wanted to keep two discrete SIDD's - so that I could tell which was 2.4 and 5 (this is not a WiFi 6 router and there is no AI Meshing).

I realised, that I had left this page out - so for completeness..

Which, if any of these settings would you change - to what - and why?

Thanks!

​

Enable Smart Connect	OFF
Band	2.4 GHz
Network Name (SSID)
Hide SSID	No
Wireless Mode	Auto AND b/g Protection
Channel bandwidth	20Mhz
Control Channel	11
Authentication Method	WPA2-Personal
WPA Encryption	AES
WPA Pre-Shared Key	Strong
Protected Management Frames	Disable
Group Key Rotation Interval	3600

Those are fine for WiFi5 ... I never mess with the special b and bg protection settings. At one time, once you did you couldn't revert it without a Reset.

Once you know your settings, especially after much tinkering, it can be a good idea to Hard Reset and configure just those settings from scratch... to get a clean install (ASUSWRT is not the most robust software!).

OE

 

[bbunge]

You can always do a factory reset and reconfigure...

 

[Woody]

You can always do a factory reset and reconfigure...

So, I could do with your advice about that: The problem is, that I have configured some fixed IP addresses in the AC86U DHCP - so if I do a factory reset, I lose all that - unless, Admin --> Save setting actually backs up (and can restore) the DHCP config?

Do you have any ideas how I could backup just the router settings (and DHCP) and then restore once factory reset?

 

[Tech9]

What would you suggest that I change in my current settings below?

Set it this way:

Band	2.4 GHz
Enable Radio	Yes
Enable wireless scheduler	No
Set AP Isolated	No
Roaming assistant	Disable
Bluetooth Coexistence	Disable
Enable IGMP Snooping	Disable
Multicast Rate(Mbps)	Auto
Preamble Type	Long
AMPDU RTS	Enable
RTS Threshold	2347
DTIM Interval	3
Beacon Interval	100
Enable TX Bursting	Disable
Enable WMM	Enable
Enable WMM No-Acknowledgement	Disable
Enable WMM APSD	Disable
Optimize AMPDU aggregation	Disable
Modulation Scheme	Up to MCS 7 (802.11n)
Airtime Fairness	Disable
Multi-User MIMO	Disable
Explicit Beamforming	Disable
Universal Beamforming	Disable
Tx power adjustment	Performance

Run Auto channel for some time, note what channel the router uses mostly, lock it and don't change it. May be different than 1-6-11.

Do you have any ideas how I could backup...

Many ideas and examples posted on SNB Forums including custom script doing exactly this. Please, use the forum search options.

 

[Woody]

Set it this way:

Band	2.4 GHz
Enable Radio	Yes
Enable wireless scheduler	No
Set AP Isolated	No
Roaming assistant	Disable
Bluetooth Coexistence	Disable
Enable IGMP Snooping	Disable
Multicast Rate(Mbps)	Auto
Preamble Type	Long
AMPDU RTS	Enable
RTS Threshold	2347
DTIM Interval	3
Beacon Interval	100
Enable TX Bursting	Disable
Enable WMM	Enable
Enable WMM No-Acknowledgement	Disable
Enable WMM APSD	Disable
Optimize AMPDU aggregation	Disable
Modulation Scheme	Up to MCS 7 (802.11n)
Airtime Fairness	Disable
Multi-User MIMO	Disable
Explicit Beamforming	Disable
Universal Beamforming	Disable
Tx power adjustment	Performance

Run Auto channel for some time, note what channel the router uses mostly, lock it and don't change it. May be different than 1-6-11.



Many ideas and examples posted on SNB Forums including custom script doing exactly this. Please, use the forum search options.

OK - have just done that - and it has selected Channel 11 - but I'll leave it, and see if it has a change of mind later.

 

[Xboxsx4life]

Set it this way:

Band	2.4 GHz
Enable Radio	Yes
Enable wireless scheduler	No
Set AP Isolated	No
Roaming assistant	Disable
Bluetooth Coexistence	Disable
Enable IGMP Snooping	Disable
Multicast Rate(Mbps)	Auto
Preamble Type	Long
AMPDU RTS	Enable
RTS Threshold	2347
DTIM Interval	3
Beacon Interval	100
Enable TX Bursting	Disable
Enable WMM	Enable
Enable WMM No-Acknowledgement	Disable
Enable WMM APSD	Disable
Optimize AMPDU aggregation	Disable
Modulation Scheme	Up to MCS 7 (802.11n)
Airtime Fairness	Disable
Multi-User MIMO	Disable
Explicit Beamforming	Disable
Universal Beamforming	Disable
Tx power adjustment	Performance

Run Auto channel for some time, note what channel the router uses mostly, lock it and don't change it. May be different than 1-6-11.



Many ideas and examples posted on SNB Forums including custom script doing exactly this. Please, use the forum search options.

Just curious…what’s the reason for using a DTIM value of 3 instead of changing it to 1? I know Asus AC routers default to 3 while AX routers default to 1…but any specific technical reason other than “that’s the default”?

 

[Tech9]

This default value perhaps comes from the wireless driver. This is what Broadcom decided is best for the radio chip used. The default value for most Wi-Fi equipment is 1. This means the client wakes up more often and checks for buffered data. Value of 3 may improve battery life on mobile devices.

 

[Xboxsx4life]

Got it. I knew about battery life. Was just wondering if there was any other reason. Thanks.

Also, I find “short” preamble works best for me (devices connect faster) but I only have 802.11n devices on my 2.4GHz network (no legacy b or g).

 

[Tech9]

Was just wondering if there was any other reason

I guess faster communications require more often buffer checking hence the change back to 1 in newer AX routers. AX also has different power saving mechanisms in place when used and supported. The person who can give you the correct answer is @sfx2000.

 

[sfx2000]

I guess faster communications require more often buffer checking hence the change back to 1 in newer AX routers. AX also has different power saving mechanisms in place when used and supported. The person who can give you the correct answer is @sfx2000.

DTIM I usually set to 4 - this helps with Android and iOS devices to do some battery savings...

BTW - Preamble can be set to short - this works for G/N/A/AC/AX - only 11b needed long preamble...

 

[Xboxsx4life]

Thanks. I haven’t noticed any adverse effects on battery life with DTIM set to 1 vs 3. I’m sure there are some but it’s hard for me to notice.

 

[sfx2000]

Thanks. I haven’t noticed any adverse effects on battery life with DTIM set to 1 vs 3. I’m sure there are some but it’s hard for me to notice.

Try that in conjunction with WMM APSD being set to true

 

[Tech9]

I never had Wi-Fi AP with DTIM 4 by default. Preamble short may work, but long may give some extra range and connection stability. Environment specific, but N and 2.4GHz in particular. Mobile devices have own power saving mechanisms. DTIM and APSD may not affect the battery life much.

 

[sfx2000]

Preamble short may work, but long may give some extra range and connection stability

I respectfully disagree - airtime is essential in WiFi, and any range benefit might be had by long preables is going to kill performance for devices that do higher rates...

Key thing is to reduce overhead - DTIM allows for scheduling of wake times (which goes back to APSD) - so while it saves some battery because the radio and device can sleep longer, it also reduces overhead messaging...

Little tip - set multicast rates to 6Mbps - this effectively disables 11b and keeps the management frames in OFDM mode - which is support by G/N/AX...

 

[Xboxsx4life]

Interesting. Thanks both. I have DTIM set to 1, preamble to short, and APSD disabled. I haven’t noticed any range, battery, or performance degradation. On the contrary actually…my devices (especially my cameras and doorbell) connect very fast. I have my 2.4GHz network separated from my 5GHz network. 2.4 is set to N-only and only for my IoT devices that don’t have 5GHz capability. All other devices are connected to 5GHz only, which is set to N/AC/AX mixed, again with DTIM set to 1 and APSD disabled. Everything works beautifully.

Also, I didn’t know preamble affected range. I thought “long” was purely extra error checking.

 

[Tech9]

I respectfully disagree - airtime is essential in WiFi, and any range benefit might be had by long preables is going to kill performance for devices that do higher rates...

I know what you are saying and it's correct, but people use 2.4GHz mostly for low rate IoT devices and long vs short preamble may be the difference between working and non-working IoT device somewhere around the edges of coverage area. Long is the default and short is an option. One or the other may work better for some. There is no universal best settings.