Home Voip Server How Can I Use VOIP With A Landline?

How can I use VOIP with a landline? - home voip server

Please read my situation before responding --
We have a few lines of the earth (more) than necessary, and an Xserve forever. I tend to make many trips abroad, and I do not want to pay too much to call home, I would like to configure a server. The server (in USA), which from my VOIP phone to say, join us, Guatemala, and then I may have a landline connected (in dollars) to another phone number () in the United States.

VOIP Phone Guatemala ---> Xserve via the Internet -> Xserve mark on the ground line ---> my parents, telephone (landline).

Is it logical, is it possible? If so .. I assume that some kind of equipment needed to fixed and Xserve Bridge. All suggestions are welcome!