Cisco does not allow porting of non-Cisco ONE perpetual AP licenses (like former Base capacity or capacity upgrade “Adder” licenses) from any older Cisco Wireless Controllers (eg. Cisco 2504, 4400, 5508, 7510, 8510 Wireless controllers) to Cisco 3504, 5520, and 8540 Wireless controller.
If you are having Cisco ONE licensing you should be able to transfer the licenses to smart, but if the licenses came pre-installed with the 5508 I have seen transfer requests were getting rejected. But depending on your relationship with SE you might be able to get it done.
By the way 5520 uses RTU licenses, so if you manage to get it converted or buy new licenses I would suggest stick to RTU, dont go through the hassle of getting smart licenses to work.
Cisco does not allow porting of non-Cisco ONE perpetual AP licenses (like former Base capacity or capacity upgrade “Adder” licenses) from any older Cisco Wireless Controllers (eg. Cisco 2504, 4400, 5508, 7510, 8510 Wireless controllers) to Cisco 3504, 5520, and 8540 Wireless controller.
