PFSense Firewall Freevoice SIP Phones
The default settings for PFSense firewall will most likely not work with Freevoice SIP Phones. The phones may register but will most likely have one way or no audio at all.
Check the PFSense Troubleshooting guide for general VoIP settings here:
Please try the following to get your Freevoice SIP Phones working properly from behind a PFSense firewall.
Disable source port rewriting - by default, PFSense rewrites the source port on all outbound traffic. Rewriting the source port of RTP can cause one way audio. In that case, you want to use manual outbound NAT and Static Port on all UDP traffic potentially with the exclusion of UDP 5060.
Set Conservative state table optimization - PFSense's default UDP timeouts are too low. Set "Firewall Optimization Options" to Conservative under System -> Advanced.