Forward sip packets from port to port?

Question

Asterisk

how to forward packets from port 6161 to 5060, I need the PBX to work on two ports at once

iptables -t nat -A PREROUTING -p udp -m udp --dport 6161 -j DNAT --to-destination net_ip:5060

iptables -t nat -A PREROUTING -p udp -m udp --dport 6161 -j DNAT --to-destination 127.0.0.1:5060

iptables -t nat -A PREROUTING -p tcp -m tcp --dport 6161 -j DNAT --to-destination 127.0.0.1:5060

Tried different options, registration does not pass.
for ssh this rule works.

Answer 1

most likely inside the sip package itself (at level 7) it is written that port 5060, iptables rules only packets at level 4. remove tcpdump there everything will be visible.