In such a network, “what you might call a connection is a consensual illusion between the two endpoints,” explains Apple networking expert Stuart Cheshire. “There are no connections in the Internet. Talking about a connection in the Internet is like talking about a connection in the US Mail system. You write letters to people and each letter goes independently—and you may have a correspondence that goes back and forth and has some continuity to it, but the US Mail doesn’t need to know about that.… They just deliver the letters.”
