title: play beep in asterisk confbridge in a specific time to all callers
body: <p>I am making a conference using asterisk conference for a group of users. </p>
  
  <p>First of all, i am using call file to call the users. When they accept the call, they are put to a conference using asterisk conf bridge. Now i need to play a beep at a specific time interval after conference has been started/user has been entered to the conference. This beep should be played to all users at a time.</p>
  
  <p><strong>Is there any method to play the beep in call file or AMI?</strong></p>