This is what shows on the iptables check..
# iptables -S
-P INPUT ACCEPT
-P FORWARD ACCEPT
-P OUTPUT ACCEPT
-A INPUT -p tcp -m tcp --dport 80 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 443 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 5015 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 5090 -j ACCEPT
-A INPUT -p udp -m udp --dport 5090 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 5060:5061 -j ACCEPT
-A INPUT -p udp -m udp --dport 5060 -j ACCEPT
-A INPUT -p udp -m udp --dport 9000:9500 -j ACCEPT
-A INPUT -p tcp -m multiport --dports 5000,5015 -m tcp --tcp-flags FIN,SYN,RST,ACK SYN -m conntrack --ctstate NEW -j ACCEPT
still error. The debain installation is not the greatest. I had to struggle to get it installed. Wish 3CX had a simple script like they do for their own on google cloud. So now can some one please provide the exact commands for the iptables? I am no server expert.