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ct2k7

macrumors G3
Original poster
Aug 29, 2008
8,387
3,442
London
In terms of protocols, how does each phone discover each others IP/etc address and route the data, which ports may be used?
 
anyone...?

I'm too really interested in learning how Facetime works under the hood. Can't figure out how it works out of the box. How are the IP address's are found by connecting a voice call?

Anyone have more details on the specifics of a Facetime call setup?
 
still don't get it...

Maybe I'm missing something, do you need to register an Apple ID or Facetime user for facetime? Does it just work out the box with your contacts list? How does the originating party find out the destinations IP address?
 
Maybe I'm missing something, do you need to register an Apple ID or Facetime user for facetime? Does it just work out the box with your contacts list? How does the originating party find out the destinations IP address?

It's made so you don't have to think like this at all. If you're in a phone call with another person who's talking on an iPhone 4, tap the FaceTime button. That's it.

Xanadeath
 
Maybe I'm missing something, do you need to register an Apple ID or Facetime user for facetime? Does it just work out the box with your contacts list? How does the originating party find out the destinations IP address?

Just works out of the box.

It's as easy as pressing one button.
 
Maybe I'm missing something, do you need to register an Apple ID or Facetime user for facetime? Does it just work out the box with your contacts list? How does the originating party find out the destinations IP address?

It's all handled behind the scenes.

You can start FaceTime either when you are in a voice call or by selecting the FaceTime option on a page in the Contacts app.

The system relies on phone numbers to connect you to the other person.
 
hello.
does facetime work if my number is private or i hide my number ??

thanks

Should do.

As long as people have your number in their contacts (or they are on a call with you) then they can start FaceTime with you.

If you try and make a FaceTime call it should work fine.
 
i just tried it.

she rang me on facetime and came up as private and it was a normal voice call then when we talked for like 1 second it requested facetime ...
 
It has nothing to do with the phone carrier, SMS or Apple IDs

I just called up an iPhone from a new iPod Touch and it works more or less instantly. But it does need to have an email account set up on both devices.

Amazing system.
 
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Here's some real detail on how it works:
http://blog.roychowdhury.org/2010/06/25/facetime-on-iphone-4-vanilla-unencrypted-stun-and-sip/

Basically it's standard SIP and uses standards based protocols. Well, all standards except it uses an Apple proprietary registration and invitation process (e.g. how the Facetime-capable phones register against Apple's servers to tell them their current IP).

I've done some of my own Wireshark analysis which matches the findings on that blog post.
 
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