This is a real question that I am curious about as an interested layman (I am not trying to be snarky or sarcastic).
It seems that all you really need to do for VOIP is encode and decode sound from a usb headset to/from mp3 or some such and send it to a peer. Can this not be done in under 2000 lines of python?
Granted, most end-users nowadays are behind a NAT, but is it really that expensive to set up a STUN server to traverse the NAT? I mean, would even this take more than a few thousand lines of python and relatively light traffic?
Also, if the move to IPv6 ever happens, will the need for NAT traversal pretty much disappear?
I am by no means an expert or even proficient at this sort of thing, so please let me know if I am missing something.