Auto channel Selection, can you limit it to a couple of channels?

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If you set your AP's to Auto Channel Selection, is it possible to limit the amount of channels it can choose from? For example it can only Auto-Assign channels 1, 8 and 11. Not from 1 to 11.

Thanks in advance :).
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Daniel Gifford

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Posted 4 years ago

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Mike Kouri, Official Rep

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Sorry, but no I don't think you can do that. Why would you want to restrict the choices?
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Brian Powers, Champ

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Agreeing with Mike on they "why", but it'd seem as if you could modify the radio profile from the stadard 1-6-11 that it defaults too and choose any 3 channels you'd like.  I didn't, however, apply this profile to multiple APs to see if any would set themselves to channel 8, but it did let me save the profile without error...



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Crowdie, Champ

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The issue with using 2.4 GHz channels other than 1, 6 and 11 is that you will experience adjacent channel interference from neighbouring 2.4 GHz wireless networks; which have implemented a standard 1, 6 and 11 channel configuration.  The adverse effect on network performance of adjacent channel interference is greater than what is experienced with co-channel interference so you, generally, are better off accepting that you will have co-channel interference in the 2.4 GHz spectrum and move wireless clients that require higher throughputs to the wider 5 GHz spectrum.
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Roberto Casula, Champ

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Hi,

Funnily enough I was about to (and will still) put a feature
request in for exactly this feature. It is actually more useful on the
5GHz radio than the 2.4GHz.

For devices like voice handsets,
there is a benefit in limiting the number of channels that are scanned
by the device as it speeds up the initial connection and improves
roaming. In the UK, for external APs, we are limited to using the
U-NII-2e channels of which there are a lot. It would be good to be able
to select a subset of the U-NII-2e channels to be used for auto-channel
assignment so that we can select a smaller number of channels to be
scanned in the device profile. For example, with a mixture of internal
and external APs, I would have liked to specify channels
36,40,44,48,100,104,108,112.

We also had a situation at one
customer where there was very frequent interference on two specific
U-NII-2 channels (60 and 64). It would have been good to be able to do
auto channel but be able to exclude these two channels.

There is
still an issue with DFS as I believe the regs say that an AP must switch
to a random channel within the particular U-NII range - I don't think
it's "legal" for that random selection to be limited - but that aside,
it would be useful.

I'm actually not a massive fan of
auto-channel, other than as a mechanism to aid initial deployment. I've
yet to find a single wireless vendor whose auto-channel algorithm works
brilliantly, though Aerohive's is as good as any other out there. What
would be useful is a one-click mechanism to statically fix channels and
power after a couple of days' "settling" of auto-channel/power. At the
moment, this requires manually modifying each AP's settings one at a
time which in a large deployment is a lot of work. With this feature, we
could let auto-channel have a good initial guess, fix that statically
with a "one click" operation and then do a final manual tweak where
necessary.

I completely agree with Crowdie as far as 2.4GHz
channel selection goes. In the UK where we can use channels 12 and 13,
unless you're in the middle of the countryside, using anything other
than 1-6-11 is likely to give you some pretty big cross-channel
interference headaches with neighbouring networks - unless of course you
can get your neighbours to all opt for the same model. The benefits of a
four-channel (1-5-9-13) or expanded three-channel (1-7-13) model are
small compared with the down-side of cross-channel interference. Also,
you may find that some devices will not connect on channels 12 and 13
anyway.

Even worse is to let the system select from all available
channels (1-11 or 1-13) as this is likely to result in some
cross-channel interference even with your own APs, especially in a
normal-to-low density deployment where the information available to ACSP
(the channel selection protocol) may not accurately reflect the
situation from a client's perspective. 1-6-11 every time for me.