How to make a modem work / ip addresses

[nantonio@can.es]

I have debian linux 2.0.33 on my mac VX.

I have an intranet server, with cern-httpd, smail, pop and I want to install
a proxy server (squid) and connect to my ISP via ppp (and tcp/ip dynamic address
for ISP and manual addresses in the intranet.

The problems I´ve found are

    1. how can I make the modem works?
       My modem is a supraFaxModem 14400

    2. How may I configure the tcp/ip and ppp to have
       manual ip addresses in my intranet and dynamic
       ip address to connect to my ISP

Can anyone help me to configure my linux system


Regards


AntonioP