Are you using nathelper? it should take care of that for you.
although old, this might point in the right direction https://nil.uniza.sk/configuring-nat-traversal-using-kamailio-31-and-rtpproxy-server/
 
Regards,

David Villasmil
phone: +34669448337


On Wed, Jan 15, 2020 at 6:47 PM Nuno Miguel Reis <nmreis@student.dei.uc.pt> wrote:
Hi guys.

I'm replacing a environment where I was using kamailio + freeswitch by another where I'm adding rtpengine to the mix.
One of the issues I'm having now is when I have a SIP Client behind NAT:

When I send the INVITE from the SIP Client, the SDP is using the private LAN IP address + the advertised media port, let's admit it's 10.10.10.10:5000 when the call establishes with a public server running kamailio + rtpengine, the actual RTP arrives from the home router public IP on a natted port, let's admit it's 100.100.100.100:65100, event though, RTPENGINE assumes that RTP stream is coming from 100.100.100.100:5000. I'm using the '--sip-source' with RTPENGINE to make it use the received ip address instead of the private IP coming in the SDP but I'm not finding anything to make RTPENGINE adapt an start sending the RTP FLOW to the port where he starts receiving the RTP flow from, discarding the SDP media port information.

In my previous setup with freeswitch alone, freeswitch did this transparently. How do you guys solve this issue in RTPENGINE?

Regards,
--
Nuno Miguel Reis
Departamento de Engenharia Informática 
Faculdade de Ciências e Tecnologia 
Universidade de Coimbra
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