Queue and limit to one active calls


I would like to build queue with two members and strategy ringball. But I would like too limit active calls to one which means :

  1. When the first client go to queue two members ringing…one member answer call
  2. When the next client go to queue, he must waiting until the first member end the call
  3. When the call is end, two member ringing.

It is impossible to do that in queue.conf ?