> 
> When I run the PPP scrips in the PPP-set of package.  I get the error:
> 
> Serial line looped back
> 
> I'm not sure what this means.  Anyone know?

If you're still connected when this happens, then the problem is
probably that your chat script isn't right. That message means that
something is echoing back to pppd the characters it is sending.
Just like the echo at a command line.

Change the command which invokes chat to also have the "-v" option
and add lines like:

local2.*	/var/log/info

to /etc/syslogd.conf and you'll start seeing all the chat action.
Something in it's wrong.

Take care,

Bill