Old Cisco Access-Points do not keep RFC 3850 rules where called-station-id should be in the format AP Radio MAC:SSID where mac address is in the format XX-XX-XX-XX-XX-XX (uppercase)
Newer Cisco AP IOS versions like 15.3(3)JD16 provide option where you can select format of called-station-id Radius attribute.
Below 3 examples of “Called-Station-ID format seen in ISE logs. SSID name is “TEST”
- default
- IETF
- unformatted