I have FreePBX 10.13.66-22 and System Firewall 184.108.40.206 with Responsive Firewall enabled hosted at FreePBXHosting.com with one NIC assigned as Internet, with whitelisted networks for admin access. All services are local or local and other (default), including SIP. I am not sure this is correct configuration.
I have blacklisted IPs that are not being blocked. Here is an example:
BTW: the traffic IS blocked outbound apparently. There is only the INVITE received and apparently no reply sent.