If regular calling plan, the setup is a bit more involved. You'd first have to find out what you "encrypted" vonage password is. The easiest way to do that is to type this address in your browser:
replacing YOUR_VONAGE_USERNAME and YOUR_VONAGE_PASSWORD with the username and pass you use to login to your vonage account. This will return a webpage with various settings and you only need to worry about the fist 4 lines: