title: FusionPBX and Freeswitch
body: <p>I have a question, which seems strange !
  I know that <code>Freeswitch</code> is a SIP Server that acts as a SIP Registrar via <code>Sofia</code> module and <code>XML</code> base <code>Dialplan</code>.
  In <code>Freeswitch</code> we can create extensions via <code>XML</code> handly. 
  In other side we have a good solution for managing and administrating Freeswitch called <code>FusionPBX</code>, It read and write data such as extensions and other configures and conference data in <code>Postgres</code> or <code>Mysql</code> database.
  And when you create an extension via FusionPBX and in <code>GUI</code> interface, it creates a field in database, and no <code>XML</code> is created,right? 
  After creating extension in <code>FusionPBX</code> and then we go to the <code>Freeswitch cli</code> and enter <code>user_exist</code> command, it display the user does not exists.
  My question is that how <code>FusionPBX</code> contacts with <code>Freeswitch</code>? How it registers extensions in <code>FS</code>? How can it start, stop <code>Freeswitch</code> services?
  And how it access <code>Freeswitch</code> services and other functionality?
  Via <code>WebService</code>? Direct access? If direct access how can it be possible? which way?</p>