Random net loss, 5g going down

[Ninj0r]

Not that this helps the OP or anyone else, but I'll share my story:

I lost my 5ghz for the first time last week and it hasn't come back yet. My RT-AC88U was running 5ghz since December on Merlin WRT with no issues. The 5ghz cut out while running 380.66 and most of the suggestions in here I had already been following (Airtime fairness off, MU-MIMO off, etc.). Tried upgrading to 380.66_4 and the current 380.67 alpha release, yet the 5ghz has stayed down through multiple reboots and radio toggles.

I haven't done a factory reset yet but it seems that will fix the issue based on what I've read on multiple forums.
There are many people reporting the 5ghz going down on ASUS routers since the beginning of this year and my assumption is this isn't related to Merlin WRT but ASUS's wifi code; most likely ASUS' attempt to get MU-MIMO out of alpha.

The one thing that DID change regarding my environment is that when I first got the router in December, there were no other 5ghz in the range of the router's wifi scan, or when using wifi analyzer from my Android. Now there are multiple 80mhz-wide channels running that I can detect. I had my router in 20/40/80mhz mode when it cut out.
I don't run my channel in auto mode because my router is the JP model and it would usually choose something in the 100-144 range which some of my non-JP equipment wouldn't recognize. I run my router on channel 48 because that's the highest channel that all of my equipment will recognize.

My 2.4ghz wifi has stayed up continuously on channel 11 in 20mhz mode as there are WAY too much 2.4ghz networks around to run 40mhz.
I force set to 11 because auto will sometimes select channel 12 or 13 which some of my US equipment won't recognize.

I'll follow up if I figure out anything useful.

 

[JMB64]

Not that this helps the OP or anyone else, but I'll share my story:

I lost my 5ghz for the first time last week and it hasn't come back yet. My RT-AC88U was running 5ghz since December on Merlin WRT with no issues. The 5ghz cut out while running 380.66 and most of the suggestions in here I had already been following (Airtime fairness off, MU-MIMO off, etc.). Tried upgrading to 380.66_4 and the current 380.67 alpha release, yet the 5ghz has stayed down through multiple reboots and radio toggles.

I haven't done a factory reset yet but it seems that will fix the issue based on what I've read on multiple forums.
There are many people reporting the 5ghz going down on ASUS routers since the beginning of this year and my assumption is this isn't related to Merlin WRT but ASUS's wifi code; most likely ASUS' attempt to get MU-MIMO out of alpha.

The one thing that DID change regarding my environment is that when I first got the router in December, there were no other 5ghz in the range of the router's wifi scan, or when using wifi analyzer from my Android. Now there are multiple 80mhz-wide channels running that I can detect. I had my router in 20/40/80mhz mode when it cut out.
I don't run my channel in auto mode because my router is the JP model and it would usually choose something in the 100-144 range which some of my non-JP equipment wouldn't recognize. I run my router on channel 48 because that's the highest channel that all of my equipment will recognize.

My 2.4ghz wifi has stayed up continuously on channel 11 in 20mhz mode as there are WAY too much 2.4ghz networks around to run 40mhz.
I force set to 11 because auto will sometimes select channel 12 or 13 which some of my US equipment won't recognize.

I'll follow up if I figure out anything useful.

This is helpful and brings up another possibility on my end. I have 2 high speed networks - 1Gbps Fiber and 100Mbps cable. I have the AC88U servicing the 1Gbps network and an AC68U on the 100Mbps network. I have both 2.4Ghz and 5Ghz channels enabled on both. I have the 5Ghz channels at 36 (AC88U) and 153 (AC68U). When I had an AC87U on the 1Gbps network with the exact same set-up, I had no 5Ghz dropping issues which is why this still seems odd to me. The channels are far enough apart that there should be no ACI/CCI and there are not a lot of other 5Ghz networks nearby - everyone is predominately using a crowded 2.4Ghz spectrum. I am not sure if Broadcom WiFi chips are more sensitive to each other or other nearby 5Ghz networks and the AC87U Quantenna chips didn't have this issue. I also have 2 Roku Ultra's and I turned off interference mitigation on the WiFi direct of their remote controls as they piggy-back on the AC88U 5Ghz network the Rokus are on. Again, the Roku remotes caused no issues with the AC87U and I am hoping they are not a potential source of this problem.

It is one thing I could try - disable the 5Ghz network on the AC68U and just have a 5Ghz network solely on the AC88U if others here feel it may be worth a try.

 

[Ninj0r]

This is helpful and brings up another possibility on my end. I have 2 high speed networks - 1Gbps Fiber and 100Mbps cable. I have the AC88U servicing the 1Gbps network and an AC68U on the 100Mbps network. I have both 2.4Ghz and 5Ghz channels enabled on both. I have the 5Ghz channels at 36 (AC88U) and 153 (AC68U). When I had an AC87U on the 1Gbps network with the exact same set-up, I had no 5Ghz dropping issues which is why this still seems odd to me. The channels are far enough apart that there should be no ACI/CCI and there are not a lot of other 5Ghz networks nearby - everyone is predominately using a crowded 2.4Ghz spectrum. I am not sure if Broadcom WiFi chips are more sensitive to each other or other nearby 5Ghz networks and the AC87U Quantenna chips didn't have this issue. I also have 2 Roku Ultra's and I turned off interference mitigation on the WiFi direct of their remote controls as they piggy-back on the AC88U 5Ghz network the Rokus are on. Again, the Roku remotes caused no issues with the AC87U and I am hoping they are not a potential source of this problem.

It is one thing I could try - disable the 5Ghz network on the AC68U and just have a 5Ghz network solely on the AC88U if others here feel it may be worth a try.

That might be a good test.
Which hardware revision is your AC88U? Mine is revision A5. You can find out the revision on the bottom of the router on the information sticker.

According to this thread: https://www.snbforums.com/threads/rt-ac88u-disabled-radio-temperature.35844/
the A5 revision changed the wifi chip from the BCM4366 to the BCM4366E. This caused my router to report the wifi temperatures as "disabled" until firmware version _65 if I recall correctly.

 

[JMB64]

That might be a good test.
Which hardware revision is your AC88U? Mine is revision A5. You can find out the revision on the bottom of the router on the information sticker.

According to this thread: https://www.snbforums.com/threads/rt-ac88u-disabled-radio-temperature.35844/
the A5 revision changed the wifi chip from the BCM4366 to the BCM4366E. This caused my router to report the wifi temperatures as "disabled" until firmware version _65 if I recall correctly.

My AC88U is also a HW revision A5 and manufactured in February 2017. I know the A5 has the enhanced version of the Broadcom 4366 WiFi chip (4366E). You are correct that Merlin's 380.66 firmware had the temp info for the newer WiFi chips restored. This leads me to further believe it is a firmware and/or WiFi driver issue as both the 4366 and the 4366E chips exhibit this issue based on the postings on all the Boards since late 2015 when the AC88U became publicly available. It still seems odd that the AC87U had no issues yet there may be an issue with the 4366/4366E chip.

 

[JMB64]

That might be a good test.
Which hardware revision is your AC88U? Mine is revision A5. You can find out the revision on the bottom of the router on the information sticker.

According to this thread: https://www.snbforums.com/threads/rt-ac88u-disabled-radio-temperature.35844/
the A5 revision changed the wifi chip from the BCM4366 to the BCM4366E. This caused my router to report the wifi temperatures as "disabled" until firmware version _65 if I recall correctly.

Well no go. I turned off the 5Ghz channel on my AC68U so I just have a single 5Ghz network on my AC88U. I then changed the channel width from 40Mhz to 80Mhz using the same channel (36) and it lasted about 90 minutes then the SSID disappeared and all clients got disconnected. This really pisses me off as this is supposed to be their flagship router and you can't use 80Mhz channel widths.

 

[m25]

Where do you find this setting in the current Merlin firmware? Is it under Professional -> Region? In this space you have a default value which for me is Singapore. Then there is also Asia, China, Europe, Korea, Russia, and United States. Is this where the regulatory enforcement is done? If so, I can try 80Mhz channel width on my default setting (Singapore).

It is on Wireless/Professional/Professional mode. The version 374.43_0 is the last one allow me to choose it off. Afterward, few versions still alow to change it from the command line and keep them after reboot, the versions after did not remember the settings after reboot. I don't know where to choose the country except the command line, mine is RO. In Tomato Shibby I can choose the right country and I do not have problem with 5G. While Tomato is very nice and fine, I still prefer Merlin.

 

[m25]

Well no go. I turned off the 5Ghz channel on my AC68U so I just have a single 5Ghz network on my AC88U. I then changed the channel width from 40Mhz to 80Mhz using the same channel (36) and it lasted about 90 minutes then the SSID disappeared and all clients got disconnected. This really pisses me off as this is supposed to be their flagship router and you can't use 80Mhz channel widths.

I think the router is fine, but the firmware generate problems: the regulated mode "on" is watching for communications in 5G band and, if it see anything, it goes down. For unknown reason, it does not goes up again.

 

[herrdude]

As an update to post #74....

After yet another 5GHz failure, I subsequently made one change to settings -- I changed channel width from 80MHz to 40MHz.

I did this 12 hours ago. The router never lasts longer than a week. So let's see...

 

[ScottW]

I did this 12 hours ago. The router never lasts longer than a week. So let's see...

I'll cross my fingers for you....

My previous record was less than 7 days. Since making the change from 80 to 40MHz, it has now been up consistently for nearly 20 days: I have devices in the Wireless Log that now show connected time of 477 hours, 46 minutes.

So that change definitely made a difference for me... But it may very well be in combination with some other settings, and not just the channel width by itself. Lots of variables, and could be any combination of them.

 

[JMB64]

I am now trying putting everything under General -> WiFi -> 5Ghz to Auto. Auto channel, Channel width of 20/40/80 (which is auto), Auto Extension channel, and checking "Optimized for Xbox" to see if that yields positive results. I am keeping "WPA-Personal" with "AES" encryption.

It is too early to tell now if this addresses the issue as it has been only 4 hours of uptime but will post later with any results.

I did see it chose Channel 149 versus when I manually chose either 36 or 44. There are 0 5Ghz networks anywhere near me so there should be no CCI/ACI happening. If this fails, I will stay on 40 Mhz channel width as that eliminates the problem and hope Asus and/or Broadcom figure out a fix as I doubt it is a hardware issue.

 

[JMB64]

Well so much for that effort. It lasted about 9 hours then the 5Ghz SSID dropped, all connections dropped, yet 5Ghz LED showed network still working. 2.4Ghz and WAN connection unaffected.

I hope Asus reads these boards and will fix this problem. On a $50 router, who cares? On a $400 router, this is
unacceptable.

 

[m25]

Please take a look here: https://en.wikipedia.org/wiki/List_of_WLAN_channels
I choose a lower channel - 36 (available with no restriction im my region) - on my N66U , disable APSD and AMPDU, bandwidth - 20/40 MHz and it seems to work fine. While choosing an upper channel (something around 100) it goes down in maximum few hours and rarely come back (mostly not), I have it now working for ~2 days. Still not ok the way of WiFi driver working, because the upper 5 GHz channels seems to be useless in those conditions, but this band have lower coverage, so lower interference with neighborhoods.

 

[JMB64]

Please take a look here: https://en.wikipedia.org/wiki/List_of_WLAN_channels
I choose a lower channel - 36 (available with no restriction im my region) - on my N66U , disable APSD and AMPDU, bandwidth - 20/40 MHz and it seems to work fine. While choosing an upper channel (something around 100) it goes down in maximum few hours and rarely come back (mostly not), I have it now working for ~2 days. Still not ok the way of WiFi driver working, because the upper 5 GHz channels seems to be useless in those conditions, but this band have lower coverage, so lower interference with neighborhoods.

Well this may explain the 5Ghz issue. Broadcom strictly enforces FCC regulations both in the U.S. and abroad. The link above shows the allowed channels in Singapore (and other countries) which support 80Mhz. As luck would have it, the drop down menu of available channels to use on my router has none of these channels. Plenty of 20Mhz width ones and a couple 40Mhz. While it is true you bond 20 or 40Mhz channels to get an 80Mhz channel, my feeling is that FCC enforcement recognizes when a channel is operating as a bonded 80Mhz channel which is not supported and it causes the drop out issue we are seeing.

I use Merlin software and I tried changing the Region setting under WiFi Professional to the U.S. or Europe and I still get the same channel list. I know this is hardwired in the Boot Loader so I am sure the GUI setting does nothing. I could be wrong but it does explain why I have no issues with 5Ghz 40Mhz or 20Mhz channel widths on the AC88U but have drop outs with 80Mhz wide channels. As this is closed source code, I am sure there is nothing Eric (Merlin) can do and is another example of the FCC overstepping its bounds into other countries.

 

[JMB64]

I Think ScottW has figured out the "fix" - at least until Asus can identify and/or address the issue. For me, 40Mhz channel width for the 5Ghz network is 100% stable with no drops on the AC88U. I have activated and de-activated many features all while keeping the 40Mhz channel width and have had no issues. So I am stuck with 40Mhz channel width for AC operation. While not ideal, it is more than enough bandwidth than I need for clients and I love all the features of the Merlin/Asus routers that Netgear/Linksys/D-Link/etc just don't have.

My only other thought as this issue appears sporadic both with the AC88U and with other Asus routers is it could be due to the the new firmware enforcement of channels, bandwidth, and Transmit/Receive power that all router manufacturers must abide by thanks to the lovely FCC. I can say for me in Singapore, I have none of the approved channels for 80Mhz bandwidth as outlined on Wiki showing on my router. I only have the channels officially designated for 20Mhz channel widths. I don't know what countries all the other posters who have been having this issue reside in but it would be interesting to get a poll of where everyone resides and who are experiencing this 5Ghz channel issue to see if there is a correlation.

 

[ScottW]

For me, 40Mhz channel width for the 5Ghz network is 100% stable with no drops on the AC88U.

Same here -- I currently have 5GHz devices that show connected for 609 hours (25+ days)! When I was using 80MHz, it never made it to 7 days without losing 5GHz despite trying other settings (including various combinations of MIMO and airtime fairness). Going to 40HMhz is the only thing that gave me stability. I'm a little irritated I can't use 80MHz, but 40MHz is sufficient for my needs so I have accepted it because -- in all other respects -- the 88U and the Merlin firmware make for a great experience.

I don't know what countries all the other posters who have been having this issue reside

I am in the US, and my house is in a rural area on acreage. While I can detect a few other 2.4GHz signals at low levels, there are absolutely no other 5GHz signals here. I have tried 80MHz with the high (149-161) and low (36-48) ranges. It *should* work fine with either range, as regulations allow it here and there are no other 5GHz signals nearby.

My only other thought as this issue appears sporadic both with the AC88U and with other Asus routers is it could be due to the the new firmware enforcement of channels, bandwidth, and Transmit/Receive power that all router manufacturers must abide by...

None of the dynamic "regulation" stuff should have been triggered in my environment, and even if it was, I would expect the correct response to be automatic fallback to 40 or 20, rather than shutting down completely and requiring a reboot. This leads me to conclude the problem is with the Broadcom hardware or drivers, or perhaps some of the ASUS closed-source code that isn't properly handling 80MHz, or not properly handling transition between 80 and fallback to 40. But obviously that's just speculation, based on observations in my own limited environment.

At this point, I am happy to have it "stable" even if it limits me to 40MHz channel width. Everything else is working great; I generally have about 30 devices active (mix of 2.4GHz and 5GHz, windows and iOS, IPCams, Smart Home devices, video streaming devices, etc). IPV6 is working flawlessly (with Comcast, no less), I have ab-solution setup for ad blocking, an ipset script for banning malicious IPs, OpenVPN server for remote access, and IPTraffic for the per-device bandwidth history.

As many others have observed... I think ASUS owes a lot of sales to Eric and his Asuswrt-Merlin firmware. I personally would have gone with a different hardware vendor (probably Ubiquity) this time instead of the AC88U had the Merlin firmware not been available.

 

[herrdude]

I'll cross my fingers for you....

My previous record was less than 7 days. wSince making the change from 80 to 40MHz, it has now been up consistently for nearly 20 days: I have devices in the Wireless Log that now show connected time of 477 hours, 46 minutes.

So that change definitely made a difference for me... But it may very well be in combination with some other settings, and not just the channel width by itself. Lots of variables, and could be any combination of them.

Almost 9 days and still going. It has been a while since (around the beginning of the year maybe) I have had the router run for longer than 6 days.

Great find!

Just out of curiosity what exactly are we sacrificing for stability?

Thanks again!

 

[ScottW]

Just out of curiosity what exactly are we sacrificing for stability?

In most cases, not much. If you have clients that support 80MHz, and they are close to the router, and the channels are clear (no interference from other routers/ap)... then 80MHz can provide more total bandwidth. In many cases, achieving all that is elusive - and 40MHz (or even 20) is therefore usually a better choice for most environments.

I currently have only one device (a laptop, usually in same room as router) that would really benefit from 80MHz, to potentially get faster bandwidth to a NAS device it accesses. But given it is usually in the same room anyway, I decided to just plug a CAT6 cable into it instead.

 

[JMB64]

Almost 9 days and still going. It has been a while since (around the beginning of the year maybe) I have had the router run for longer than 6 days.

Great find!

Just out of curiosity what exactly are we sacrificing for stability?

Thanks again!

ScottW is correct. Very few clients can truly take advantage of full 80Mhz channel width. It is best used for AP to AP or AP to Wifi Bridge connections. 80Mhz channel widths are very susceptible to so many room environment issues and other potential sources of interference like adjacent 20 Mhz channels that rarely are you always getting the full bandwidth the channel width can deliver. Also unless your internet connection is 1Gbps or more, why do you need 866Mbps to 1.3Gbps client bandwidth anyways? Along with greater stability, 40Mhz channel widths with 802.11ac WiFi still provide high throughput that the majority of clients can all utilize, standardized beam-forming, and MU-MIMO abilities. These are not all available with 802.11n (40Mhz channel widths but no standardized beam-forming and no MU-MIMO) and not at all available with 802.11b/g.

 

[Joboo7777]

Created an account jus to post this. I had similar 5GHz issues along with extender connection issues described in this thread. I've tried everything, even resetting to factory Firmware with no luck. Must be a HW issue.

I ended up returning the AC88u and purchasing an AC3100(just because it was available at the local BB) and so far all is good!

 

[bandit8623]

68u here. Changed to 40mhz and all my devices now stay connected as well. Thanks for the help