After soft were don't have siri
Don't have Siri and face team after software
iPhone 4, iOS 6, Siri and face team
Siri runs on iPhone 4S or later, same for FaceTime ...
*FaceTime video calling requires a FaceTime-enabled device for the caller and recipient and a Wi-Fi connection. FaceTime over a cellular network requires iPhone 4S, iPhone 5, or iPad (3rd generation) with cellular data capability. Availability over a cellular network depends on carrier policies; data charges may apply.
From here > http://www.apple.com/ios/facetime/