Hello;
i installed kamailio V 4.3.2 and Asterisk 13.5 version the same machine. Kamailio listens 5061 port and asterisk listens 5080 port. When the calls happens , asterisk sends perfectly 200 Ok message to Kamailio and then kamailio sends to UAC. But UAC sends to ACK message to kamailio , kamailio flooding itself. Ack messages sends itself. i changed to nat_uac_test variable to 19 / 23 and else. Couldn't find why kamailio cannot send ACK to ASterisk.

UAC ->-- INVITE:5061--->KAMAILIO->-INVITE:5080---->ASTERISK

UAC ->-- 200 OK:5060--->KAMAILIO-<-200 OK:5061---<-ASTERISK

UAC ->-- ACK :5061--->KAMAILIO->- ACK :5061---->-KAMAILIO

KAMAILIO->- ACK :5061---->-KAMAILIO
KAMAILIO->- ACK :5061---->-KAMAILIO