When you're "opening the NAT," you're really just port forwarding.
The Linksys WRT150N is an 802.11n wireless home router. Designed for full-time use in the consumer market, the WRT150N has several user-configurable features that you can access and control from its built-in administrator page. "Opening the NAT" is a term used primarily in gaming circles to enable your wireless console to connect to the Internet using your wireless router. This is a process that involves port forwarding. Fortunately, Linksys' internal admin page does most of the heavy lifting for you.
Instructions
1. Launch your web browser, type "http://192.168.1.1" into the address bar and press "Enter."
2. Click the "Applications and Gaming" tab along the menu at the top of the screen.
3. Click the "Single Port Forwarding" button along the top of the screen. Enter the ports that need to be forwarded into the "External Port" and "Internet Port" boxes. If you're unsure of which ports need to be forwarded for your device, consult the user's guide or product website.
4. Enter your computer's IP address into the "To IP Address" field. To find your computer's IP address, click the "Start" menu and select "Run." Type "ipconfig" and press "Enter."
5. Click the "Save Settings" button at the bottom of the page