Welcome to the world of DTM
There's an easy four step process that does this same thing.
1. Start a conversation with your friend.
2. Open a command prompt and type netstat -a
3. Send the friend a voice clip or a file.
4. redo the netstat -a and you'll see their IP address in the list.
Have a great day:)
Never mind the fact that alot of these five to ten dallor a month service providers will have everything shared between their subscribers.