Firstly, is your modem installed correctly, and does it work under normal circumstances? When you install RAS, you need to specify the modem. Make sure RAS is configured to Receive Calls Only or Dial Out and Receive Calls. There can be quite a few things you need to look at, but first verify that your modem is indeed working correctly (try plugging a telephone into it), and that all your RAS configs are set correctly.