RT-N66U 5ghz drops randomly

[illfated]

The 5ghz AP disappears for a random time. Guest networks and 2.4ghz are not affected.
I checked with my phone and wifi analyzer when the 5ghz disappears its completely not visible under any channel of the 5ghz range.
I had this with the original Asus firmware and with Merlins. I've reset my NVRAM a couple of times.
I tried all the settings under the wireless tab (20/40, N/Legacy, etc etc) none made a different.
With the Original firmware the 5ghz used to disappear for longer periods of times. Sometimes it wouldnt come back until i restarted the router. With Merlin it usually comes back in under a minute but still annoying if I'm watching a video on chromecast and it loses the connection.
I've checked the log during the times it drops but theres nothing I found useful

Thats the only kind of thing I see there:

Jul 20 20:24:06 kernel: SKIPPED false Type 2 Radar Detection. min_pw=76 pw_delta=0 pri=21123 fm_min=0 fm_max=0 nconsecq_pulses=3. Time from last detection = 14274, = 237min 54sec. Detected pulse index: 12
Jul 20 20:29:27 kernel: SKIPPED false Type 1 Radar Detection. min_pw=75 pw_delta=0 pri=25850 fm_min=0 fm_max=0 nconsecq_pulses=3. Time from last detection = 320, = 5min 20sec. Detected pulse index too high: 43
Jul 20 20:31:11 kernel: SKIPPED false Type 5 Radar Detection. min_pw=76 pw_delta=0 pri=61313 fm_min=0 fm_max=0 nconsecq_pulses=0. Time from last detection = 425, = 7min 5sec. Detected pulse index: 17
Jul 20 20:34:57 kernel: SKIPPED false Type 1 Radar Detection. min_pw=77 pw_delta=0 pri=55309 fm_min=0 fm_max=0 nconsecq_pulses=3. Time from last detection = 225, = 3min 45sec. Detected pulse index too high: 33
Jul 20 20:45:42 kernel: SKIPPED false Type 1 Radar Detection. min_pw=83 pw_delta=0 pri=29630 fm_min=0 fm_max=0 nconsecq_pulses=3. Time from last detection = 871, = 14min 31sec. Detected pulse index: 0
Jul 20 20:49:38 kernel: SKIPPED false Type 7 Radar Detection. min_pw=69 pw_delta=0 pri=5327 fm_min=1030 fm_max=0 nconsecq_pulses=4. Time from last detection = 235, = 3min 55sec. Detected pulse index: 0
Jul 20 20:51:36 kernel: Type 1 Radar Detection. Detected pulse index=0 fm_min=0 fm_max=0 nconsecq_pulses=3. Time from last detection = 118, = 1min 58sec

 

[MichaelCG]

This looks like DFS biting you in the rear. What channel are you using?

 

[ColinTaylor]

I've checked the log during the times it drops but theres nothing I found useful

Jul 20 20:51:36 kernel: Type 1 Radar Detection. Detected pulse index=0 fm_min=0 fm_max=0 nconsecq_pulses=3. Time from last detection = 118, = 1min 58sec

If the outages occur when you see this message that is the reason. If the router detects Radar activity on its channel it will switch to another one, but there will be a 60 second outage while it does this. I had this with my N66U.

If you select a non-DFS channel you will not see this problem.

 

[illfated]

Jul 20 20:51:36 kernel: Type 1 Radar Detection. Detected pulse index=0 fm_min=0 fm_max=0 nconsecq_pulses=3. Time from last detection = 118, = 1min 58sec

If the outages occur when you see this message that is the reason. If the router detects Radar activity on its channel it will switch to another one, but there will be a 60 second outage while it does this. I had this with my N66U.

If you select a non-DFS channel you will not see this problem.

Thank your for your tip.
DFS channels are: 52-64 / 100-140
Correct?
So I'd have to pick a channel between 36 - 48.
The problem is my WiiU uses channels from 36 to 44 (from what I've seen 48 might be in it too) and if I set my router to those channels the WiiU gets a choppy signal. And the WiiU doesn't seem to pick another channel if my router is using it. But I'll try it and see if I get those drops again. I'll report back later thanks for now.

 

[FreshJR]

Thank your for your tip.
DFS channels are: 52-64 / 100-140
Correct?
So I'd have to pick a channel between 36 - 48.
The problem is my WiiU uses channels from 36 to 44 (from what I've seen 48 might be in it too) and if I set my router to those channels the WiiU gets a choppy signal. And the WiiU doesn't seem to pick another channel if my router is using it. But I'll try it and see if I get those drops again. I'll report back later thanks for now.

Where are you getting your WiiU channel numbers? Since I guess it uses whatever is open?

I have seen mine use channel 161 and 165 on the 5ghz

 

[MichaelCG]

What country are you in? That may possibly be whey they don't see 161 as an option.

 

[FreshJR]

USA. Those are valid USA channels.

 

[illfated]

I'm in Germany. My router just goes to 136 and I've never seen my WiiU use the above 100 channels. So I used to set my router to those. I'm using 48 now and haven't got a drop yet but my WiiU is getting constant drops as it uses the channels between 36 and 48 which are used by other AP around here + mine.

 

[MichaelCG]

How many of the DFS channels have you tried? Sounds like your choices are more limited than those of us in the US, so you may just try various DFS channels until you find one that doesn't detect interference.

 

[illfated]

By now I tried about all of them I think. I was running on channel 136 for a week now and it was fine but now it started doing the disappearing again. I checked the APs around and they're far from channel 136. Closest one is 112something.

edit: it disappeared again and didnt come back anymore
Jul 31 14:40:41 kernel: SKIPPED false Type 7 Radar Detection. min_pw=155 pw_delta=0 pri=7479 fm_min=1030 fm_max=0 nconsecq_pulses=4. Time from last detection = 14072, = 234min 32sec. Detected pulse index too high: 52

 

[RMerlin]

By now I tried about all of them I think. I was running on channel 136 for a week now and it was fine but now it started doing the disappearing again. I checked the APs around and they're far from channel 136. Closest one is 112something.

edit: it disappeared again and didnt come back anymore
Jul 31 14:40:41 kernel: SKIPPED false Type 7 Radar Detection. min_pw=155 pw_delta=0 pri=7479 fm_min=1030 fm_max=0 nconsecq_pulses=4. Time from last detection = 14072, = 234min 32sec. Detected pulse index too high: 52

Don't use DFS channels, you are in an area where the channel will have to be freed whenever a radar signal is detected. Move to a non-DFS channel like 36.

 

[Marko Polo]

Don't use DFS channels, you are in an area where the channel will have to be freed whenever a radar signal is detected. Move to a non-DFS channel like 36.

Merlin, could you please elaborate your idea? What channels are considered DFS?
I also see these messages often

Apr 13 09:00:43 kernel: SKIPPED false Type 4 Radar Detection. min_pw=332 pw_delta=0 pri=14711 fm_min=1030 fm_max=0 nconsecq_pulses=5. Time from last detection = 145, = 2min 25sec. Detected pulse index: 0

 

[john9527]

Merlin, could you please elaborate your idea? What channels are considered DFS?
I also see these messages often

Google can help....first one on the list when searching 'DFS channels'
https://www.tp-link.com/us/faq-763.html

 

[Marko Polo]

Google can help....first one on the list when searching 'DFS channels'
https://www.tp-link.com/us/faq-763.html

Thx. So I should avoid channels 52-140 (aka DFS) in order not to experience such skipping?

 

[john9527]

Thx. So I should avoid channels 52-140 (aka DFS) in order not to experience such skipping?

Correct. Note that the channels that are actually available may change depending on your region.

 

[Marko Polo]

Correct. Note that the channels that are actually available may change depending on your region.

OL. And one small question concerning implementation of DFS function in Merlin: if I un-tick this box,

the firmware will start to search only non-DFS channels that are physically available (in my region) now or it will enumerate all channels and can run against empty channel thus interrupting the connection?

 

[john9527]

If you don't tick that box, it should stay away from the DFS channels, so should eliminate the radar detection drops.

 

[FreshJR]

The problem is my WiiU uses channels from 36 to 44 (from what I've seen 48 might be in it too) and if I set my router to those channels the WiiU gets a choppy signal. And the WiiU doesn't seem to pick another channel if my router is using it.

I've seen my wiiu on the upper end of 5ghz as well (148 - 161) as well as on the low end .

I think it chooses a free channel upon bootup and uses it until next bootup.