Call Forwarding variables

Where does the EPM Pull this info from asterisk

Call Forward Busy - On String

P26309 = cfbOn

Call Forward Busy - Off String

P26310 = cfbOff

Call Forward Delayed (No Answer) - On String

P26311 = cfnaOn

Call Forward Delayed (No Answer) - Off String

P26312 = cfnaOff

Call Forward Unconditionally (All) - On String

P26313 = cfaOn

Call Forward Unconditionally (All) - Off String

P26314 = cfaOff