Some of the ATT routers also provide you with UPnP feature. To enable this feature launch a web browser from your computer or mobile which is connected to your router? Enter the router name and password if not changed, enter the default name and password to log in. select Advanced and then click on Advanced setup and then your
ATT router UPNP setting would be enabled. The final step would be to select the UPnP checkbox and you are all set to go. It assumes local programs and trustworthy and allows them to forward ports. There’s no right choice as to whether you should keep this feature on or off.