Hi, Here are same problems in my configuration of kamailio server. I have two kamailio server (both have a NAT IP and a lan IP), and I use DNS to keep loadbalance.When sending message to another account , if NAT IP which is returned by DNS, is not the same as receiver account, kamailio server sends 404 not found error. I really have no idea how to set the configuration when using DNS loadbalance to return two NAT IP. Thank you , I'm looking forward from you! Sincerely yours Ada WU