User Configuration\Administrative Templates\Network\Network and Dial-up Connections
Determines whether the Dial-up Preferences item on the Advanced menu in Network and Dial-up Connections is enabled.
If you enable this policy, the Dial-up Preferences item is enabled. If you disable this policy, it is disabled. By default, Dial-up Preferences is enabled.
The Dial-up Preferences item lets users create and change connections before logging on and configure AutoDialing and callback features.