AT&T: UPnP?

you can´t use both UPnP and Port Forward.

Be sure that you only run 1 option.

UPnP OR Port Forward OR DMZ. A home Router can´t handle more than 1 option and then disconnects like you describe.

Delet all Port Forwarding and DMZ and leave UPnP enabled. Then Restart your Router - so the Ports get cleard. Problem should be solved then.

If you use UPnP you don´t need Static IP´s. On my Xbox (only one) I use UPnP and if I give my XBOX an Static IP my NAT type gets back to moderate. That makes no sense for me - maybe it´s the implementation of UPnP in my router. Only if I don´t give my xbox
a static IP and use UPnP my XBOX works with open NAT. Try to change your xbox to a non static IP Adress. and restart your Router.

Thank you for contact us! I'm Anderson, an Independent Consultant and a Microsoft user like you.

Good evening

Enable UPnP (Universal Plug and Play): UPnP allows devices on your network to automatically configure network settings, including NAT types. To enable UPnP on your AT&T hotspot device, access its settings interface (usually through a web browser) and look for UPnP or NAT settings. Enable UPnP if it's not already enabled.

If you connect two xboxes over the same router. you can´t use DMZ or Port Forward.

her some one eplain why it will not work !

www.tomshardware.co.uk/.../37462-17-xbox-360s-router-switch

But I read many times that UPNP can solve this Problem !

Try to use the Option UPNP in your Router. The restart your Router and the your Xbox. Your NAT should be open on both xboxes.

Try to search the newest firmware and use UPNP. If you use UPNP Port Forward AND DMZ have to be disabled because home Routers can´t use UPNP AND DMZ or Port Forward.

Do not forget to restart your Router.

If you enable UPnP you can´t use DMZ also.

So enable UPnP and disable DMZ an then RESTART your Router.

If you then start your xbox it should work with open NAT.

Be sure you run the latest Firmware for your Router.