when ever I call someone, I got "_______ is unavailable for face time," and she try's to face time me, gets the same thing!

Me and my friend are trying to face time, she has a Ipod5th i have a 4th were not on the same wifi, infact were provences apart. I dont know why its doing this but it wont work! :/

Its gives both of us that message, I havnt face timed before, but my account is set up and everything