Anwendungs Server als Client betreiben mit Indy

[QuickAndDirty]

I'm in the process of reading on STUN and TURN.
I think it will be a STUN/TURN server combination at the end.
I was baffeled that all but symmetric NAT are basically unsafe and open to the STUN procedure...
Every NAT that can use STUN is basically vulnerable for a port scan.
That's why all NAT/Firewalls out there in corporate newtworks are symmetric NAT.
So these Symmetric NAT need a relay server that can also relay TURN connections.

Now I'm trying to under understand ICE candidates and why the way they are exchanged isn't part of the god damn specification.