I am the solo IT guy at a company that resells cellular modems. I have been tasked by my boss to put together some training for the salesmen and hardware support guys on some networking concepts. I need to make sure they understand about things like Public vs. Private addresses, NAT, and Port Forwarding. It should not be too technical, and I don't need to cover the OSI model or subnetting for example.
Can anyone suggest resources for effective ways to turn nerd speak into normal speak so that these guys can get it? What analogies or visuals have you used to help people understand these concepts?