Venturing into VOIP

[NollipfSense]

So, I am expanding my lab by venturing into VOIP using FreePBX. I am interested in what works with pfSense and to hear from those who had taken this path. I have been reading: https://docs.netgate.com/pfsense/en/latest/nat/configuring-nat-for-voip-phones.html

Please share your configurations especially firewall. I had also checked Traffic Shaping section of the forum; however, threads with VOIP I saw were not answered.