You will normally hear continuous dial tone when you lift the handset. You will hear discriminating dial tone (also called interrupted dial tone) or transfer dial tone under certain conditions.
You will hear discriminating dial tone (or interrupted dial tone) when you lift the handset if you have:
activated Do Not Disturb
enabled Call Forward (Follow Me or I Am Here)
not logged in to your ACD telephone.
You will hear the transfer dial tone when you generate a flash to put an established call on Consultation Hold. Transfer dial tone is 350/440 Hz with a cadence of 0.1 seconds on and 0.1 seconds off (3 times) followed by continuous dial tone.
None.
None.
None.