FaceTime always says failed!!

[Kavalpatel7]

When u try to FaceTime my friend(wifi is on he is online too and he never gets my call) it says FaceTime failed can you please help me!!!!

 

[iArnie]

I can't get FaceTime to work over wifi either. I'm trying between an iPhone 4S on wifi and an iPad 3 on wifi. It worked with iOS 5 with the same settings, but won't work on iOS 6.