Message Waiting Indication if enabled should Play stutter dial tone
MWI if enabled (asterisk.set1.mwi_enable='1') stutter tone should be played ( DIALTONE_SPECIAL_CONDITION ).If disabled dial tone is played ( DIALTONE_ON ) But in case the asterisk.set1.mwi_dialtone_state (by default on) is set to any value ( 'off' || 'congestion' || 'special' || 'on' ) and a message is waiting, The dial tone is set according to the mwi_dialtone_state.