Facetime works without activated SIM?

[fireshot91]

So, my brother's iPhone 4 SIM card gets deactivated because he got a different phone. And then today, I noticed it had a missed Facetime call. I didn't return it, but, I tried entering my friend's phone number in the contacts and then started a Facetime with her, and it worked!
Needless to say, I was surprised.

I'll ask my friend what number it came from, on the off chance that it was my brother's phone number. I'll post back/edit in a few.

EDIT: Okay. So, the call did come from my brother's phone number. But the SIM card had no service, and wasn't active.

 

[mackmgg]

FaceTime only uses the SIM to get the phone number originally, after that it just uses your phone number as your username for FaceTime. Both phones would probably ring if someone called his number

 

[fireshot91]

FaceTime only uses the SIM to get the phone number originally, after that it just uses your phone number as your username for FaceTime. Both phones would probably ring if someone called his number

But they didn't. It only rang when it was FaceTime initiated.

 

[scootaru]

FaceTime does not operate on the cellular network. His iPhone 4 had to be connected to your home network via wifi. The SIM is no longer used after FaceTime is initially set up. The iPhone does verify a SIM is installed, however, before starting FaceTime, but it doesn't have to be the original SIM that was installed when FaceTime was set up.