If there is a firewall or a router between the Xbox console and the networking hardware, and if the Xbox LIVE test reports an NAT problem, you may have to make configuration changes to enable communication on the specific network ports that are required by Xbox LIVE. This reconfiguration is known as "port forwarding." If you use an Xbox LIVE-compatible device or a Windows Vista-compatible device that has the correct firmware installed, you should not have to make these changes.