2N Helios IP Configuration Manual page 78

Hang-up by remote party – here replace the disconnect tone signalling that
the called station has hung up.
Busy tone – replace the standard busy tone.
Invalid input – replace the invalid switch code sound.
Invalid position – replace the speed dial button sound signalling a non-
programmed telephone directory position.
Switch activation – replace the switch activation sound.
Ringing – replace the standard incoming ringing tone when the Automatic
call answering function is off, refer to the Miscellaneous
subsection.
Configuration 2.3
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