Now before you think I'm simply trying to use a 360 to play media on a NAS, I can tell you that the situation is more tricky than that.
I'm using my Asus WL520gu router flashed with tomato as a wireless ethernet bridge (where it receives a wireless signal and just acts as ports). I've hooked my Xbox 360 directly to the tomato router. I play Windows Media Center fine, and can stream good quality video. However, I'd like to stream 1080p movies, but it doesn't work well on wireless. That's why I've also set up the tomato router to use native USB support and attached an external hard drive to it. I'm hoping that since the hard drive and 360 are both directly connected to the tomato router, the transfer of 1080p files would be faster. It's a tricky idea, I know.
However, it works as well as if i connected the external hard drive to the computer hosting Windows Media Center. I'm unfamiliar with the processes of Windows Media Center, but I'm guessing that the 360 sends requests to my computer through the wireless ethernet bridge and then finds the mapped drive on the tomato router. I'd like to make it so that the Xbox realizes that it has a direct connection to the router with the hard drive attached to it.
What can I do to eliminate the middleman of the computer which is connected wirelessly? Is there some sort of port forwarding on the tomato router where I can forward the 360 ports directly to the hard drive connected via USB?