Why can't I give opposite public ip address?

[hyunsooda]

In your examples(chat, chat-with-rendezvous) we can give only loopback address(127.0.0.1) instead our real ip address(public ip).

I tested without router but it remains printed error. So this is not real application because we can chat on only local environment.

Do you know why can't I give a opposite public ip address?

One more question:
There are three peers connected each other. It destroy all connections if a peer terminate own process(ex. Ctrl+C)
Even if a peer terminate own process, other guys(2 peers) should not impact about that and remains connected between 2 peers. I think that 2 peers should receive EOF if a peer close his socket(process termination), however this example was not working as my guess