What ports must I open on the firewall to enable audio in zoiper?

When freepbx is on DMZ everything is OK.
But I want to it be more secure, so I want to open only the ports needed.
I opened these ports but no luck. Zoiper registers but I have no audio during a call

eth0 5060 TCP ACCEPT
eth0 4569 UDP ACCEPT
eth0 8000 UDP ACCEPT
eth0 3478 UDP ACCEPT
eth0 3478 TCP ACCEPT

Which are the correct ports to open?