Who is calling me is getting busy tone though my iphone not off too.
If turn-on "do not disturb" on your iphone who is calling you will getting busy tone though.
How Can I Turn Off "Do Not Disturb"
If you want deactive that "do not disturb" you should open control center.
To view the control screen; Swipe up from the bottom of the screen and tap to crescent (moon) icon.
If active "do not disturb" on your iphone who is calling you, will getting busy tone though.
If deactive "do not disturb" on your iphone who is calling you, won't getting busy tone though.
If you want see other options for "do not disturb" long tap the icon.
