CNF FILE creation in CME - 9.1

Question

Hi - I need clarity on below points.
By Default CNF Location is System CNF-File is PhoneType, As per below if its not supported how its creating CNF Files when we give create cnf-files ?
Whats the Advantage between Per phone type and Per phone
Per phone type—Creates separate configuration files for each phone type and all phones of the same
type use the same configuration file. This method is not supported if the configuration files are to
be stored in the system location.
Per phone—Creates a separate configuration file for each phone, by MAC address. This method is
not supported if the configuration files are to be stored in the system location.

Answer 1

Hi Kirill - I tested that, I just want to understand difference between Phone Type and PerPhone in which scenario we have to go Phone Type/Phone 
2. By Default location is system and cnf files is Phone Type if the system is not supported for Phone Type/Perphone why we have defualt location as System.