iPod touch FaceTime troubles...

[SuperMacMan]

I'm having quite a time here trying to get FaceTime working between two iPod touch 4's.

They both work correctly when connected to my home WiFi network, and we have been able to FaceTime each other fine.

However, when my friend goes home and I try and call them or they try and call me, it won't work. Either my iPod/their iPod rings, but when answering, it just disconnects after a brief period of "connecting...".

I can verify that my iPod is working fine, because I have FaceTime'd others from home and it has worked fine. However, the friend has not tried the same thing.

Can anyone shed any light as to what's wrong?

 

[Bacong]

Firewall settings, I'd gather.

 

[SuperMacMan]

Firewall settings, I'd gather.

That's what I thought, but they've disabled every bit of firewall and filtering and no dice. We've also checked the port forwarding settings, and they were already set to what Apple says in their support doc for FaceTime.

Anyone have any ideas?