Cisco 2500 Series Wireless Controllers Release 8.5 Software. In order to use 8.4 or higher code, you must upgrade the 2504 Wireless Lan Controllers to FUS version 1.9 or higher, this must be done before installing the new AireOS version.
Cisco 2500 Series Wireless Controllers Release 8.5 Software.In order to use 8.4 or higher code, you must upgrade the 2504 Wireless Lan Controllers to FUS version 1.9 or higher, this must be done before installing the new AireOS version.