Hi guys, i have a kamailio running on the wan (my central kamailio) and i have phones on a private network range 172.20.0.0/16 behind a NAT. i also run another kamailio locally to collect all sip phones on my network and this one use the DB of the remote central kamailio. the local kamailio does t_relay_to() the ip of the central kamailio route { if (uri==myself) { if (method=="REGISTER") { route(2); exit; }; route[2] { rewritehost("public_remote_kamailio"); if(!t_relay_to("udp:public_remote_kamailio:5060")) { sl_reply_error(); }; exit; } the bad thing is once the phones get registered with non-routable ip (like in the attached picture) trying to INVITE them directly by requesting public_kamailio_ip result in non-working situation. how should I rewrite my dst_domain when registring in a way INVITE triggers to the local kamailio. My local kamailio runs with the listen udp:private_local_kamailio advertise udp:public_local_kamailio I try to be explicit but my understanding is not perfect, it would be nice you could give me a hand. I put my local kamailio.cfg attached. thx