Charles,
We discovered this a couple of months ago during our initial setup/rollout of
the Cisco product. I believe there is a "US2" setting in the DCA templates (at
least in 5.1) that exclude the UNII-2e channels.
In out testing, the latest Apple iMac's with integrated BCM43xx do support
UNII-2e, but nothing else that we've tested including the popular Intel 4965AGN
or Atheros chipsets (think MacBook Pro) do. I've been told by our Cisco SE that
the latest Intel 5100 and 5300 also support UNII-2e.
Given our diverse client base, I think UNII-2e is basically off-limits to us
for the next 3-4 years. By 2011-2012, must of our client-base should have
turned over, and hopefully most will be supporting UNII-2e.
Jeff
>>> Charles Spurgeon <[EMAIL PROTECTED]> 9/10/2008 7:41 AM >>>
FYI. This documents something that we have stumbled over with UNII-2e
channels and is a "heads up" for anyone running Cisco LWAPP gear and
using the auto channel selection component of RRM ("Dynamic Channel
Assignment" (DCA) in Cisco-speak).
The Cisco WLC release notes for v4.1.185.0 have an important caveat
(CSCsi86794) that describes the behavior of DCA and the UNII-2
Extended channels (UNII-2e).(1) For some reason this caveat is missing
in 4.2.130.0 release notes, while the DCA issue still appears to be
present in that code. (Based on the text in the 4.1.185.0 release
notes the UNII-2e support appears to have first shown up in
4.1.171.0.)
Briefly, Cisco has added support for the UNII-2e channels to the
wireless lan controller and LWAPP APs, and these channels are
automatically enabled for use by DCA.
As a result of the new support, AP radios may be automatically
assigned by DCA to one of the UNII-2e channels. We found several
radios in our system where that had happened.
Unfortunately, none of the 802.11a clients that we have tested know
about the UNII-2e channels, and therefore most (all?) 802.11a clients
cannot associate with AP radios that have been assigned to the UNII-2e
channels. An AP radio on one of those channels is no longer available
to dot11a clients and your wireless coverage will have holes in it
even though the AP is up and system monitors are happy.
If the client NIC has an 802.11an radio then it may have support for
the UNII-2e channels. You would need to test against an AP radio set
to one of the UNII-2e channels to find out, since the vendor docs that
we have looked at don't tend to have any documentation about the
presence or absence of UNII-2e support.
To avoid this issue, Cisco's release notes tell you to disable the
UNII-2e channels in DCA. However, the release notes incorrectly tell
you to also disable channel 149, which is NOT one of the UNII-2e
channels. Instead, it is one of the older channels that is supported
by all 802.11a NICs that we've tested.
If you want to avoid issues with AP radios being set to UNII-2e
channels that are invisible to clients then you can do that by
disabling all DCA channels in the UNII-2e range of 100-140.
Note that when you disable these channels using either the CLI or the
Web GUI the AP radios must be disabled and then re-enabled to make
that change.
We would be interested in hearing about the experience at other sites
with UNII-2e channels, especially the results of any tests of UNII-2e
support in clients.
Thanks,
-Charles
Charles E. Spurgeon / UTnet
UT Austin ITS / Networking
[EMAIL PROTECTED] / 512.475.9265
(1) The UNII-2e channels appear to be relatively recent
additions. This Cisco doc mentions them in the context of DFS support
requirements: http://tinyurl.com/yq7y9r
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