Windows NT version 4.0 supports a feature known as AutoDial. Windows 95 and Windows NT version 3.51 and earlier do not support the AutoDial feature.
When an attempt to connect to a network address fails because the host cannot be reached, the AutoDial feature can automatically start a dial-up connection operation. To do this, AutoDial searches its database of network addresses to find a phone-book entry that it can use to establish the connection.