Yes, the predictive dialer mode is designed to work in that specific scenario, adjusting the calling pace to the number of agents you have. SIP Caller will make the calls, rule out busy calls, not answered calls, or calls answered by an answering machine, and only transfer to a queue of agents the calls connected to a real person. SIP Caller can monitor in real time the status of this queue in your Phone System, so it knows how many calls are waiting, the number of available and busy agents, queue configuration settings like the wrap up time, and much more. It can also learn from the history of the campaign (previous calls made), and determine a call transfer rate, i.e. how many calls are transferred to the queue of agents. With this information, SIP Caller can predict the number of calls it has to start in order to fill the queue with calls for the agents you have.