You'll want to use 20 MHz channels in the 2.4GHz band. That's the only way to get the 3 non-overlapping channels (channels 1, 6, and 11). When you switch to 40 MHz channels, then you end up with one non-overlapping channel because you have to bond 1 & 6 or 6 & 11 to get the 40 MHz channel.
I don't have my 5 GHz channel list handy, but if you normally have 12 non-overlapping channels at 20 MHz widths, then you will have half that when you enable 40MHz channel widths.
I have not done a lot of testing with 802.11n on a controller (just played around at home with a few standalone APs). All things being equal, your difference in channels widths is (40Mhz on the 5Ghz versus 20MHz on the 2.4GHz) explains the speed difference.
Also, be aware that speeds will typically jump around depending on your location (with respect to the AP), how many other clients are associated to the AP, the presence of 802.11a/g clients, the presence of 802.11b clients, interference, and a whole host of other factors. Don't expect to always get the best speed from your APs - even if you are 3 feet from one.
Transferring Crash file from standby:
Login to the Active WLC in HA.
(Cisco Controller) >transfer upload datatype crash
(Cisco Controller) >transfer upload filename <Desired filename>
(Cisco Controller) >transfer up...
This is the start of a display filter cross reference between Wireshark and OmniPeek.
The 1st installment is a table of advanced filters. More filters will be added as time allows.
It is a living doc, so check back for changes every so often
Please feel ...
I have created a Powershell script to automatically add a Wireless Guest User on Cisco WLCs. (tested on 2500 Series)
The script should be completely self explanatory.
Powershell SNMP Module (Install-Module -Name SNMP)
SNMP Write Access to...