iPod touch FaceTime failed

[Christian 5G]

Wirelessly posted (Mozilla/5.0 (iPod; U; CPU iPhone OS 4_2_1 like Mac OS X; en-us) AppleWebKit/533.17.9 (KHTML, like Gecko) Version/5.0.2 Mobile/8C148 Safari/6533.18.5)

I was calling from iPod touch4G to my friend on iPhone 4 and it shows FaceTime failed what is that, please really need help with that, or how to call from iPhone to iPod touch FaceTime?

 

[S.B.G]

Try using Tango, which also works over 3G.

 

[Christian 5G]

Wirelessly posted (Mozilla/5.0 (iPod; U; CPU iPhone OS 4_2_1 like Mac OS X; en-us) AppleWebKit/533.17.9 (KHTML, like Gecko) Version/5.0.2 Mobile/8C148 Safari/6533.18.5)

Thanks, he just realized that he have to turn on FaceTime on in settings- phone