02-20-2014 08:47 AM
Working with a customer today and found they have two different flavors of Cisco IP Phones (7925 and 7925-EX) The EX is the same as the plain 7925, but with a pretty yellow explosion-proof skin. They have sites with both Cisco or Aruba AP's deployed and they have found the 7925-EX's never associate with the 5Ghz radios in the Aruba equipped sites.
We did some research (Thanks Colin) and found a few other posts related to the 7925, and went through disabling Channel 165 and disabling WMM. No help, but probably good items to consider.
Only after reading this blurb from the Cisco Guide, did we piece it together.....
If using the Cisco Unified Wireless IP Phone 7925G World (-W) model, the Cisco Unified Wireless IP Phone 7925G-EX or
Cisco Unified Wireless IP Phone 7926G model, then it is required to enable 802.11d. The Cisco Unified Wireless IP Phone
7925G gives precedence to 802.11d to determine the channels and transmit powers to use and inherits its client configuration
from the associated access point.
Enable World Mode (802.11d) for the corresponding country where the access point is located.
Some 5 GHz channels are also used by radar technology, which requires that the 802.11 client and access point be 802.11h
compliant if utilizing those radar frequencies (DFS channels). 802.11h requires 802.11d to be enabled.
The Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G will passively scan DFS channels first before engaging in
active scans of those channels.
If 802.11d information is not available from the access point, then the Cisco Unified Wireless IP Phone 7925G (-A, -E, -P)
model uses the locally configured regulatory domain. If the Cisco Unified Wireless IP Phone 7925G -A, -E or -P model is
taken to another country, where the access point uses a different regulatory domain, then 802.11d will be required for the Cisco
Unified Wireless IP Phone 7925G to operate successfully.
If using 2.4 GHz (802.11b/g) and 802.11d is not enabled, then the Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and
7926G can attempt to use channels 1-11 and reduced transmit power. (So essentilally, if you want to use these models with 5Ghz, you must have 802.11d enabled).
Note: World Mode is enabled automatically for the Cisco Unified Wireless LAN Controller.
so we tested by enabling 802.11d/h... (Radio Profile).
Need to have it enabled on both bands in order for client device to scan/utilize the 5Ghz radio correctly.