Cutomize Speeding of Queue to distributor

Hi everyone
I’m building small call center (use freepbx) about 60 seat.
And have problem with my queue. I know when incoming to my queue, it dial (ringing) one agent then the agent answer, my queue continue dial second agent.
And I wanna custominze speed my queue to it distribute quickly my agents (no need the first agent must answer).

 Example: I have 20 agent available and 20 incoming.
               I want the first call dial the first agent
                         the second call dial the second agent
                         .........
                         the 20th call dial the 20th agent.

Thank you for your advice.