Error 734 - The PPP link control protocol terminated.
Resolutions: 1. this is most like security issue, for example, you set to send encrypted passwords and your RAS server does not support encrypted passwords, or reverse situation. Check the security settings on both sides.
2. if multi-link negotiation is turned on for the single-link connection, disable it.
3. This error may occur if you are using user-defined callback in your DUNS setup.
4. Also refer to error 691.