I Phone problem

I have noticed that when I use the volume buttons on the left side of the phone that I see a red bell with a slash through it. I presume that is telling me that the ringer is off. If so, how do I get rid of the bell?

My out-of-state long distant calls are not ringing in to the phone and if they do, they go immediately to voice mail (it does not seem to effect local calls). How do I correct this?