Trying to figure out if it is possible to access my PBX via Acrobits Groundwire and a cell phone (Vodafone) but without the use of the Responsive firewall.
With it it works fine.
Trying to see wether i can disable the onboard firewall and use a different approach with the iptables or with an external firewall.
For the phone’s IP, look up an address that it is using. The carrier probably has a small range that you can whitelist, e.g. a /24 but likely no larger than a /20. Use a nonstandard SIP port, and/or use SIP over TLS (or at least TCP) instead of UDP.