AX1100 - can't use most control channels

[giglio_networkio]

Hi team,

I've got an AX11000 running Merlin 388.1.

I was tinkering around with the 5GHZ-2 settings as I recently got on 1GB fiber optic internet. I thought I'd make the 5GHZ-2 channel AX only and try to get as much speed out of it as possible. I found a few strange things, and I'm thinking maybe this behavior falls under the category of "known limitations that I am unaware of".

• I can't use 160MHZ bandwidth at all. Doesn't matter if I explicitly set it, it only ever does 80MHZ. This one seems reasonable because, from what I'm reading on the forums, the router has many ways to detect interference and bounce down to something lower and it seems likely that there is interference around here as I'm outside Barcelona, and it's pretty
• If I try 160MHZ and set any control channel (even 100), the radio doesn't work. Similar to the next item, the network doesn't show up when I use these settings. Even though it automatically selects channel 100, the radio stops working if I manually try to use the same channel.
• Even when using 80MHZ bandwidth, most control channels don't work for me. I can select them, apply the settings, etc., but it seems that the 5GHZ-2 radio doesn't work. The network doesn't even show up. No errors were reported (I'm not looking in logs, just in the UI). I could only get this to work control channel 108 or lower.
• Auto channel selection always picks channel 100. I looked at the site survey tool, and many other networks use channel 100 as a control channel and nearby channels as extensions, but auto-select seems to default to 100.
• My channel selection tops out at 128. I bought this router in the UK and now use it in Spain. I seem to remember another device I had that would go up to 160 something. This one is almost certainly expected, I just thought the UK and Spain permitted higher channels than 128.

Interestingly, when I looked at this reference for WLAN channels, I saw that only a few channels in the upper range seemed to support 160MHZ. Not sure if that is when used as a control channel or what. For example. 114 and 163 are the only ones that look like they work well with 160MHZ bandwidth, but maybe I'm reading the charts wrong.

I know I've listed a lot of different things here, I'm just curious if anyone has seen similar weirdness with the AX11000 or other routers. I did try searching around in the forum. I saw someone else with 160MHZ issues on AX11000, but it looked like more of a UI problem.

Anyway, thanks for your time and attention! This is a great forum, it's nice to be here and benefit from the collective wisdom.

 

[ColinTaylor]

Go into the Wi-Fi settings and change the Channel bandwidth option to 20MHz (or 20/40/80/160). Now click on the dropdown list for Control channel. What channels do you see?

 

[giglio_networkio]

With 20MHZ bandwidth, the available channels reach 140 (100, 104, 108, 112, 120, 124, 128, 132, 136, 140).

 

[ColinTaylor]

With 20MHZ bandwidth, the available channels reach 140 (100, 104, 108, 112, 120, 124, 128, 132, 136, 140).

Did you miss out 116? If so, you have the same as the upper part of my UK dual (not triple) band RT-AX86U. In other words, it's working as expected. The only possible 160MHz block is 100-128 (assuming you do have 116).

On the other 5GHz radio you have one 160MHz block from 36 to 64.

You said that "Even when using 80MHZ bandwidth, most control channels don't work for me". If the channel block you've chosen includes any channels from 120 to 128 (weather radar) there will be a 10 minute wait time before the SSID becomes available. Using 160MHz will always include those weather channels, so there will always be a 10 minute wait time for that.

 

[drinkingbird]

Hi team,

I've got an AX11000 running Merlin 388.1.

I was tinkering around with the 5GHZ-2 settings as I recently got on 1GB fiber optic internet. I thought I'd make the 5GHZ-2 channel AX only and try to get as much speed out of it as possible. I found a few strange things, and I'm thinking maybe this behavior falls under the category of "known limitations that I am unaware of".

• I can't use 160MHZ bandwidth at all. Doesn't matter if I explicitly set it, it only ever does 80MHZ. This one seems reasonable because, from what I'm reading on the forums, the router has many ways to detect interference and bounce down to something lower and it seems likely that there is interference around here as I'm outside Barcelona, and it's pretty
• If I try 160MHZ and set any control channel (even 100), the radio doesn't work. Similar to the next item, the network doesn't show up when I use these settings. Even though it automatically selects channel 100, the radio stops working if I manually try to use the same channel.
• Even when using 80MHZ bandwidth, most control channels don't work for me. I can select them, apply the settings, etc., but it seems that the 5GHZ-2 radio doesn't work. The network doesn't even show up. No errors were reported (I'm not looking in logs, just in the UI). I could only get this to work control channel 108 or lower.
• Auto channel selection always picks channel 100. I looked at the site survey tool, and many other networks use channel 100 as a control channel and nearby channels as extensions, but auto-select seems to default to 100.
• My channel selection tops out at 128. I bought this router in the UK and now use it in Spain. I seem to remember another device I had that would go up to 160 something. This one is almost certainly expected, I just thought the UK and Spain permitted higher channels than 128.

Interestingly, when I looked at this reference for WLAN channels, I saw that only a few channels in the upper range seemed to support 160MHZ. Not sure if that is when used as a control channel or what. For example. 114 and 163 are the only ones that look like they work well with 160MHZ bandwidth, but maybe I'm reading the charts wrong.

I know I've listed a lot of different things here, I'm just curious if anyone has seen similar weirdness with the AX11000 or other routers. I did try searching around in the forum. I saw someone else with 160MHZ issues on AX11000, but it looked like more of a UI problem.

Anyway, thanks for your time and attention! This is a great forum, it's nice to be here and benefit from the collective wisdom.

There are only two 160mhz channels possible (less in some countries) and they both overlap DFS and frequently will drop to 80. If you have two 5ghz radios, it will be even harder since you're trying to get double the amount of spectrum. My advice is to stick with 80mhz non-DFS, that is capable of nearly 1Gbps on AX 2-stream and will be more stable.

 

[tgl]

My advice is to stick with 80mhz non-DFS, that is capable of nearly 1Gbps on AX 2-stream and will be more stable.

Yeah, this sure sounds like it's DFS-avoidance problems at bottom. The only 5GHz channels that are problem-free under UK/EU regulations are 36-48 which of course are just an 80MHz block. If you live in the middle of nowhere you have more options, but near a major airport? Nope. Set the router on 20/40/80MHz (not including 160) bandwidth, pick one of those channels as control channel, and think longing of the days when more spectrum will be opened up for WiFi.

 

[drinkingbird]

Yeah, this sure sounds like it's DFS-avoidance problems at bottom. The only 5GHz channels that are problem-free under UK/EU regulations are 36-48 which of course are just an 80MHz block. If you live in the middle of nowhere you have more options, but near a major airport? Nope. Set the router on 20/40/80MHz (not including 160) bandwidth, pick one of those channels as control channel, and think longing of the days when more spectrum will be opened up for WiFi.

Sucks over there apparently, that basically means if you want to use both the 5Ghz radios you need to set them to 40 or have one suffer the DFS consequences from time to time.

 

[tgl]

Sucks over there apparently, that basically means if you want to use both the 5Ghz radios you need to set them to 40 or have one suffer the DFS consequences from time to time.

Yeah, dual-5GHz-radio APs seem to be of questionable value for our European friends.

If you are in an area where DFS channels are unreliable, you could try choosing different control channels within 36-48: use 36 or 40 for one radio and 44 or 48 for the other, and be sure to select variable 20/40/80 bandwidth for both radios. That gives you at least some benefit from your hardware purchase: the radios can operate independently at 20MHz or 40MHz bandwidth, and only when they try to open up to full 80MHz bandwidth do they conflict.

(If you're thinking you were sold this gear under false pretenses, I would not argue. It can't be used to full value except in rural areas where you probably don't have a fast enough internet connection to justify it.)

 

[giglio_networkio]

Did you miss out 116? If so, you have the same as the upper part of my UK dual (not triple) band RT-AX86U. In other words, it's working as expected. The only possible 160MHz block is 100-128 (assuming you do have 116).

On the other 5GHz radio you have one 160MHz block from 36 to 64.

You said that "Even when using 80MHZ bandwidth, most control channels don't work for me". If the channel block you've chosen includes any channels from 120 to 128 (weather radar) there will be a 10 minute wait time before the SSID becomes available. Using 160MHz will always include those weather channels, so there will always be a 10 minute wait time for that.

Hey there! I did miss 116, my bad.

I had no idea about the 10-minute wait. I will give it a try and wait to see what happens. Thanks!

 

[giglio_networkio]

One more question: Is there a good way to measure what kinds of signals traffic/interference you have on DFS channels? I was curious if there is a metric worth looking at that would help me confirm that, yes, its XYZ type of noise that causes the router to back down to 80MHZ.

 

[ColinTaylor]

Not really. You'd also have to monitor it continuously over time as a lot of interference is transitory. That said, some Asus models have/had a "WiFi Radar" tab in the GUI that collected WIFI channel statistics. Personally I found the information it reported as somewhat dubious.

Bear in mind that depending on how exactly you've configured your router it may initially drop from 160MHz to 80MHz if there are no 160MHz-capable clients connected. Once such a client does attempt to connect the router will switch back to 160MHz mode.

 

[drinkingbird]

One more question: Is there a good way to measure what kinds of signals traffic/interference you have on DFS channels? I was curious if there is a metric worth looking at that would help me confirm that, yes, its XYZ type of noise that causes the router to back down to 80MHZ.

As @ColinTaylor said nothing great within the Asus. There are access points you can buy that have better capabilities and full site survey setups etc but I'm assuming you don't want to invest in that. However the system log will tell you when it dropped channel width or changed channels due to DFS rules.

 

[giglio_networkio]

You guys have already helped me a ton because I had no idea about the 10-minute wait time. I got slightly better behavior than before; now, when I set it to 160MHZ and channel 116, it takes 10 minutes and then shows up on channel 100 at 80MHZ, lol.

I'll have to have a peep at the system and wireless logs

 

[drinkingbird]

You guys have already helped me a ton because I had no idea about the 10-minute wait time. I got slightly better behavior than before; now, when I set it to 160MHZ and channel 116, it takes 10 minutes and then shows up on channel 100 at 80MHZ, lol.

I'll have to have a peep at the system and wireless logs

That's the point of the 10 minute scan. That means channel 116 is not available due to weather radar use and thus you cannot get 160mhz on anything other than the UNII-1 and 2 range, which you're probably using for your 5Ghz-1.

Sounds like the only 2 channels you have available are 36-64 (160mhz) and 100-112 (80mhz).

If you want the 160 on your 5ghz backhaul then use it there and use 80 for your clients. Or in reality, 80 is plenty on AX so just use two different 80 mhz channels, you can have one completely avoid DFS and the other will be in DFS but sounds like that range is clear in your area (assuming you can maintain 160 currently on that lower range).