From a Joel's post on Copilot:
Direct Connect! We’ve always done
everything we can to make sure that
Fog Creek Copilot can connect in any
networking situation, no matter what
firewalls or NATs are in place. To
make this happen, both parties make
outbound connections to our server,
which relays traffic on their behalf.
Well, in many cases, this isn’t
necessary. So version 2.0 does
something rather clever: it sets up
the initial connection through our
servers, so you get connected right
away with 100% reliability. But then
once you’re all connected, it quietly,
in the background, looks for a way to
make a direct connection. If it can’t,
no big deal: you just keep relaying
through our server. If you can make a
direct peer-to-peer connection, it
silently shifts your data onto the
direct connection. You won’t notice
anything except, probably, much faster
communication.
How do they change the server connection to a P2P connection?
