NAT is a rating of your ability to interact with other players over xbox live / PSN if it is Strict then your interactions with other players, like chat or messaging, will be slow or challenging. it does not affect lag only interactions with others. Consoles have their own tests for it and so do games.For example my xbox says my NAT is Open where MW2 says it's Moderate. Your NAT could be low if you have an old or outdated router that is not compatible with video game systems.If you have an xbox you can go to xbox.com and search NAT
