[rescue] low end Suns as telephone <--> IP devices?

[Patrick Giagnocavo]

Let's say that I have to communicate with people in another country on a
regular basis.  Normal phone calls to this place are expensive, but
unlimited net access IS available.

Here is my thinking:

USA computer with mic and speakers
     |
     |
compressed audio stream
     |
     |
Intl computer with IP address
     |
     |
some device that can be controlled to connect to POTS phone line

If I did it this way, I would only have to pay for the Net access on
both ends, plus the phone line at the international place.

I was thinking that a LX or higher would be needed, but aside from that
everything would work as soon as I figured out what the last device is
and how to build it or buy it.  All it needs to do is generate the DTMF
tones to dial the phone, then "listen" and send the audio both ways.

Anyone done anything like that?  Is there a simple device (I am guessing
a modem + sound chip) that could do this for me?

Any help appreciated.  

./patrick