xbox 360 and new motorola modem nvg510

i know this might be a little late but it willl be helpfull wht you have to do first is find ur ip address to do that 

1.click on the start button of ur computer/laptop and type cmd and press enter

2.next type ipconfig your ip address is where it says Default gateway copy it down because youll need it

3. open the browser and type ur ip address and then press enter

4.after that click on Firewall then on Nat/Gaming

5.after u click on nat/gaming it should appear with Application Hosting Entry click on service and scroll down till you find Xbox Live 360 where it says needed by device you need the ip address of the your Xbox 360 to find that got to System Settings and click on Network Settings click on your wired connection or wire connection and then click Configure Network there you will find your ip address for your 360

6. last of all click on Needed By Device and click on the ip address of your 360 and then click add and it should refresh and say something like changes save 

now when you go back on CoD or other games you play online your nat type will be open i hope this helps you message me back if you need more help

Neither the fix mentioned above or the fix on http://www.dslreports.com/forum/r27716102- solve the problem of video stuttering from microsoft hosted videos running on the xbox 360.  Other video streaming (e.g., netflix, hulu) work fine but MS stuff still stutters every 3 to 5 seconds.  PS3 uers have been reporting a similar problem.

Looks like still no solution to this very likely modem hardware/software and/or att service design failure. att, motorola, microsoft, sony are all not able to resolve the matter (they naturally point to each other).

As of 11/23/13, no reports found for XBOX One or PS4 user issues associated with uverse using nvg510. They will likely start showing up over the next few weeks unless those vendors have found a way to work around motorola/att failures.

As of now we are having NAT problems with both the XBOX ONE, XBOX 360 and the ARRIS NVG510, and in order to have it fixed you must pay $50.00 to ConnecTech to have them walk you through it. I am sorry but I don't feel as though we should have to pay this seeing as how AT&T could just make a better gateway, or find a competitor that can do what their current business partner can't. For about 6 months I have had no problems. Then a week ago my NAT type switched to Moderate. Went in and switched it back, then two days ago it changed again on it's own to Strict. Port 3074 UDP and TCP, Port 53 UDP and TCP, Port 80 TCP, Port 88 UDP have all been opened...and worked for about 2 days. Even now they are still under hosted applications, but the NAT type is still strict. Even reseting the gateway, turning it off, turning off the xbox's, the computer....still nothing works.