title: making Call conference using USB Modem/Android Phone
body: <p>As the question's title tell the most about the problem.</p>
  
  <p>Here is some more detail on what I wish to do, but having no background in this field facing many problems to make it possible.</p>
  
  <p>I want to connect a SIM with my Computer using USB Modem, or Android phone which ever solve my question.</p>
  
  <p>Keeping it connected, I read about in some other question that we can make call using <strong>DotRas</strong>, I searched a lot but couldn't find anything for Call conference.</p>
  
  <ul>
  <li>Is this possible..?</li>
  <li>And if yes, can someone help me to achieve this..?</li>
  </ul>
  
  <p>or at least hint on What should I learn to be able to do this type of work.</p>
  
  <p>Ready to learn in both Windows/Ubuntu, if it is possible in any...</p>