Sorry for my late response, but thank you for replying. I read the "Secure NDMP" document a little more closer. However I can't seem to find this document anymore on Netapps website. Anyhow, it does mention that data connections are not part of their Secure NDMP implemntation. Here is the relevant text from the document:
The data channel would continue to remain as it is. There is no encryption planned for data channel communication.