[Discuss] peer to peer software

[blu at nedharvey.com (Edward Ned Harvey (blu))]

> From: discuss-bounces+blu=nedharvey.com at blu.org [mailto:discuss-
> bounces+blu=nedharvey.com at blu.org] On Behalf Of Stephen Adler
> 
> It seems to me from reading the comments that p2p is basically all
> about p2p discovery.

...  Well...  And NAT traversal.


> I also realize that from the discussion, the
> internet is now broken. The way p2p is obviously supposed to work is
> sending out a broadcast udp message querying "the internet" for peers.

The idea of broadcast beyond your LAN is insane.

The "normal" way to do this is:  You use broadcast on your LAN, and additionally connect to some 3rd party machine on the internet, followed by NAT traversal, and if NAT traversal fails, then you fallback to a relay server on the internet.  For example, when you use facetime or similar, both parties must connect to the IM server, which very likely provides STUN and/or TURN services and similar, to hopefully facilitate your NAT traversal.  And like I said, failing that, fallback to a relay on the internet.

Even if you had IPv6 and completely public world routable IP addresses, you still cannot expect to broadcast on the internet.  IPv6 sure does simplify all that NAT traversal stuff and relay servers though.  You only need to know the other party's IPv6 address, and you're done.