Ako si ti na primer na jednom ISP-u i NAT-ovan, a onaj drugi na drugom ISP-u i takodje NAT-ovan, direktna veza ne moze da se uspostavi. Tada je jedino moguce da npr. razmenjujete fajlove preko nekog programa...npr. MSN Messenger.
Bob Hodges(Colors):"There's two bulls standing on top of a mountain. The younger one says to the older one: "Hey pop, let's say we run down there and fuck one of them cows". The older one says: "No son. Lets walk down and fuck 'em all"