You can’t just ‘enable NAT’ you have to also configure’ it (likely with iptables (read firewall) rules.) Mostly rules for SIP (VOIP) REGISTER and INVITE and other for any SDP (AUDIO) connections, SIP might be ‘transported’ on UDP, TCP, TLS. WS, WSS , maybe more , SDP (audio) in asterisk is usually apparent on a mathematically incorrect range of 10000-20000)
Such rules allow for calls to arrive on your ‘external IP’ and be handled by your PBX, any resultant audio/video connections and reverse connections are mostly accepted and properly routed then.
Can we presume that incoming calls work?
