configure kamailio and rtpengine behind NAT -- 3

I set up kamailio and rtpengine behind NAT, and make DMZ for kamailio server. I add advertise pub ip for kamailio in configure file with listen= [login to view URL] advertise pub ip and config rtpengine with --interface=localip!pubip. now the problem is when I using UA from local call the UA on internat, verything is ok, except the SDP of ACK to local UA, the connection info c= pub ip, this should be local ip of kamailio.