If your Windows NT RAS server has the Callback feature enabled, your Windows NT RAS client can configure the callback delay. The default is 12 seconds. Navigate to:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RasMan\PPP

From the Edit menu, Add Value name DefaultCallbackDelay as a type REG_DWORD and set the decimal value to any number between 0 and 255 seconds.