- Create a connection in Windows, and dial it with Windows to make sure the connection works.
- Dial that same connection in your application using DotRas to ensure what you're passing into the dialer works as you expect.
- Use the RasPhoneBook class to open the phonebook containing the connection in step 1 while debugging and write down all the settings that Windows used for your entry (this might take a while).
- Replicate the settings identified in step 3 to your code that creates your own custom entry.
- Dial that new connection created in step 4 from your application as you tried to do originally.