iptables -A FORWARD -p udp --sport 53 -j ACCEPT
iptables -A FORWARD -p udp --sport 1571 -j ACCEPT
iptables -A FORWARD -p udp --sport 5060 -j ACCEPT
iptables -A FORWARD -p udp --sport 8000 -j ACCEPT

iptables -A FORWARD -p udp --dport 53 -j ACCEPT
iptables -A FORWARD -p udp --dport 1571 -j ACCEPT
iptables -A FORWARD -p udp --dport 5060 -j ACCEPT
iptables -A FORWARD -p udp --dport 8000 -j ACCEPT