Ok.. Since Happy think's he's soooo smart.. I'll put it in smaller terms...
Think of it like a landline....
Person "A" makes a phone call, and the call is "ringing", and hasn't connected, and Person "B" tries to call person "A", what happens? Busy signal right? RIGHT!
Sooo.. In the iPhone's case, it uses call forwarding to send person "B" to person "A"'s voicemail, until person "A"'s call connects, and call waiting can be used...
Why does this not make sense...
Oh yeah, and I may live in Charleston, but I'm not from here, because this place is a little dense.. You midlands people have GOT to be a little quicker.
Now, I'm off to have my mommy tuck me in, because it sucks being 35 and single and living at home...