I am setting up Raspberry Pi to run Kamailio with mediaproxy-ng. This machine is running on local LAN behind a DSL router. Using dynamic DNS and DMZ services of router, i can access this box from the Internet.

However, i do not know how to define advertised_address parameter to public IP of router. The public IP is dynamic and changes roughly every 12 hours or so. Is there any way kamailio can automatically learn this dynamic public IP and use that as advertised_address?

Something similar to Asterisk's res_stun_monitor module,

https://reviewboard.asterisk.org/r/854/