With an OPEN NAT type, you’re able to chat with other people, as well as join and host multiplayer games with people who have any NAT type on their network.

With a MODERATE NAT type, you’re able to chat and play multiplayer games with some people; however, you might not be able to hear or play with others, and normally you won’t be chosen as the host of a match.

With a STRICT NAT type, you’re only able to chat and play multiplayer games with people who have an OPEN NAT type. You can’t be chosen as the host of a match.