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Subject: Re: RFC: Remote Off-Channel CAC for DFS
To:     Johannes Berg <johannes@sipsolutions.net>,
        linux-wireless@vger.kernel.org
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From:   Markus Theil <markus.theil@tu-ilmenau.de>
Message-ID: <9f36bb56-8aa6-e759-5024-cfe5e58e41cf@tu-ilmenau.de>
Date:   Mon, 29 Jun 2020 22:00:06 +0200
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On 6/29/20 9:35 PM, Johannes Berg wrote:
> Hi,
>
> On Mon, 2020-06-29 at 19:40 +0200, Markus Theil wrote:
>> When using DFS channels, it would be nice, if I could dedicate a small
>> amount of interfaces only to CAC checking channels and set them
>> available or unavailable on multiple other remote APs/Mesh Points in
>> order to use them, when switching to lower utilized channels without
>> going through a full CAC.
>>
>> Whats the opinion on the mailing list about adding a new command to
>> nl80211 in order to set the DFS state of a currently not used channel
>> after a Off-Channel CAC on another device nearby, but not on the same
>> host? The parameters would roughly be the same as for a channel switch
>> and an additional DFS channel state. Internally, I would trigger the DFS
>> state sync code between multiple interfaces.
> But wait, don't we already sync this within the kernel?
Yes, the kernel already syncs this between interfaces on the same host.
I'd just like to sync between multiple hosts, in order to make use of
fast switches to other DFS channels in a mesh network (in my case), if
some other node nearby already had performed a DFS CAC of a particular
channel and sync this state between hosts.
> johannes
>