It only means your phone is set to divert. You may not be able to receive calls on your phone but instead to the number you have set it to divert to.
Where do I find the number that is suppose to be my "set to divert" number. I have never set up a number. Have had phone for over a year and it has just started doing
this. My calls (made from my phone to my husband's) are not going through properly.