[N66U] DFS channels missing in Merlin-Fork

[Grisu]

And, I would be willing to bet most (all?) existing client drivers aren't going to be updated to support the new rules.

Thats chicken or the egg dilemma!

With this approach we will never ever get more usable channels!

First you need to have service stations (router) to support you with new fuel before you will get cars (clients) using it.

 

[shobhitk]

And, I would be willing to bet most (all?) existing client drivers aren't going to be updated to support the new rules.

i guess then we wont be needing it.

Thanks for the support to all of you!

 

[RMerlin]

Actually, it's just almost impossible to keep up with the FCC. The latest 'New Rules', allow for DFS channel support in the US (I had to look it up...ALL the DFS channel are now allowed)

But the device would require re-certification. The RT-N66U was never certified to operate on DFS channels.

 

[sfx2000]

And, I would be willing to bet most (all?) existing client drivers aren't going to be updated to support the new rules.

There's quite a few clients that do support DFS - it's easier for client stations to pass the FCC/EU-RED testing, as all they need to prove is that they don't initiate transmissions in the DFS channels - they can passively scan, and if they find an AP in the DFS, they can safely assume that the DFS requirements have been met by the AP itself.

In my collection of client adapters, the only one that doesn't support DFS is the Asus USB-AC56 - at least not under Linux...

I do have a WiFi to Ethernet adapter - it does support DFS bands, but it's hard-coded to JP, and it is older, so it does not support UNII-3 channels (CH149-CH165)

From the Asus - iw list output - disabled channels removed - reg domain set as US via iw reg set US

Note they do bump power in the 5GHz UNII-1 band to 30 dBm which is handy...

* 2412 MHz [1] (30.0 dBm)
* 2417 MHz [2] (30.0 dBm)
* 2422 MHz [3] (30.0 dBm)
* 2427 MHz [4] (30.0 dBm)
* 2432 MHz [5] (30.0 dBm)
* 2437 MHz [6] (30.0 dBm)
* 2442 MHz [7] (30.0 dBm)
* 2447 MHz [8] (30.0 dBm)
* 2452 MHz [9] (30.0 dBm)
* 2457 MHz [10] (30.0 dBm)
* 2462 MHz [11] (30.0 dBm)

* 5180 MHz [36] (30.0 dBm)
* 5200 MHz [40] (30.0 dBm)
* 5220 MHz [44] (30.0 dBm)
* 5240 MHz [48] (30.0 dBm)
* 5745 MHz [149] (30.0 dBm)
* 5765 MHz [153] (30.0 dBm)
* 5785 MHz [157] (30.0 dBm)
* 5805 MHz [161] (30.0 dBm)
* 5825 MHz [165] (30.0 dBm)

 

[sfx2000]

But the device would require re-certification. The RT-N66U was never certified to operate on DFS channels.

Yep, and the amount of testing required for DFS is massive - many OEM's avoid it unless it's beneficial for them (example, Orbi does support DFS, but they kinda have to - Apple does support DFS with their Airports).

Some insight here as to the challenge -- https://wireless.wiki.kernel.org/en/developers/dfs

 

[john9527]

@sfx2000
A couple of things that piqued my curiosity....
- @ColinTaylor mentioned that he thought new AC68s were shipping with a country/rev of Q2/12 which yields

US (Q2/12) UNITED STATES
wl -i eth2 channels
36 40 44 48 52 56 60 64 100 104 108 112 116 120 124 128 132 136 140 144 149 153 157 161 165

If that's the case, I need to take care of enabling radar detection for the DFS channels (it's done separately in the firmware)
- The OP with an N66 is defaulting to country/rev of Q2/0. I've never heard of the N66 using Q2, it's always been US. The firmware can change the rev, so I'm wondering if the stock ASUS firmware is dynamically changing things to allow DFS in the US.

 

[sfx2000]

If that's the case, I need to take care of enabling radar detection for the DFS channels (it's done separately in the firmware)
- The OP with an N66 is defaulting to country/rev of Q2/0. I've never heard of the N66 using Q2, it's always been US. The firmware can change the rev, so I'm wondering if the stock ASUS firmware is dynamically changing things to allow DFS in the US.

Maybe - one of the interesting things with Broadcom NIC's in my experience though - you can send commands to the chip that are outside of limits, and it'll say "ok", but then not do it... Power Levels are a good example of how Broadcom implemented Write Once Memory - and this is documented in the FOSS Broadcom sta driver...

I'm thinking this might also apply to reg_domain - you'd need to query the chip itself to see what it's actually set to, and this would be outside of CFE - asking the chip directly

 

[RMerlin]

Yep, and the amount of testing required for DFS is massive - many OEM's avoid it unless it's beneficial for them (example, Orbi does support DFS, but they kinda have to - Apple does support DFS with their Airports).

Some insight here as to the challenge -- https://wireless.wiki.kernel.org/en/developers/dfs

Recently an (unreleased) Asus router went through a permissive change on the FCC as they recertified the device for DFS usage. I can imagine that aside from the involved paperwork, re-testing in a lab must be fairly expensive as well. Not something you'd spend on a nearly-EOL device like the 6 years old RT-N66U.

This recent FCC filing as well as recent code change indicate that Asus is going to have some new devices support DFS channels in the US in the near future.

merlin@ubuntu-dev:~/amng/release/src/router$ cat config/config.in | grep DFS
config RTCONFIG_DFS_US
    bool "DFS US support"
config RTCONFIG_RALINK_DFS
    bool "Rlink DFS support"
merlin@ubuntu-dev:~/amng/release/src/router$

 

[onix]

I hope I'm not hijacking the thread, but does anyone know what the following configurations in nvram mean? Incidentally googling: Q2 country code, did not come up with much.

admin@RT-N66R:/tmp/home/root# nvram show | grep country
wl0_country_code=Q2
wl0_country_rev=32
wl_country_rev=32
wl1_country_code=Q2
wl1_country_rev=32
...

 

[ColinTaylor]

@onix See posts #12 and #26. It means your router is configured for the US market.

 

[Grisu]

I hope I'm not hijacking the thread, but does anyone know what the following configurations in nvram mean? Incidentally googling: Q2 country code, did not come up with much.

admin@RT-N66R:/tmp/home/root# nvram show | grep country
wl0_country_code=Q2
wl0_country_rev=32
wl_country_rev=32
wl1_country_code=Q2
wl1_country_rev=32
...

On my 86U set to Asia, Singapore and US it will show Q2/992 while China CN/63, Australia CN/998, Europe EU/962, and some others.