GSM Modems, PCs, SMS and Telephone Calls
<p>What all would be the requirements for the following scenario:</p>

<blockquote>
  <p>A GSM modem connected to a PC running
  a web based (ASP.NET) application. In
  the application the user selects a
  phone number from a list of phone nos.
  When he clicks on a button named the
  PC should call the selected phone
  number. When the person on the phone
  responds he should be able to have a
  conversation with the PC user.
  Similarly there should be a facility
  to send SMS.</p>
</blockquote>

<p>Now I don't want any code listings. I just need to know what would be the requirements besides asp.net, database for storing phone numbers, and GSM modem.</p>

<p>Any help in terms of reference websites would be highly appreciated.</p>
