Hello @renrick,
What you have now configured in your Asterisk server is accepting traffic with port 5060 (chan_pjsip) and then sending out traffic with port 5060 towards your gateway.
If you want to send traffic back and forth with port 5160 you will need to set it up on both sides (the gateway and the asterisk). Your inbound calls hits the pjsip trunk (port 5060) and goes out on port 5060 (your gateway port).
Thank you,
Daniel Friedman
Trixton LTD.