Hello, My pbx has a dynamic ip address and i am using the name myhost.dyndns.org for it. Until now i have had the following settings: vars.xml <X-PRE-PROCESS cmd="set" data="external_rtp_ip=host:myhost.dyndns.org"/> <X-PRE-PROCESS cmd="set" data="external_sip_ip=host:myhost.dyndns.org"/> Internal profile <param name="ext-rtp-ip" value="$${external_rtp_ip}"/> <param name="ext-sip-ip" value="$${external_sip_ip}"/> However, with this I was getting a public ip in the contact header of the calls. So i had to change the internal profile to <param name="ext-rtp-ip" value="autonat:$${external_rtp_ip}"/> <param name="ext-sip-ip" value="autonat:$${external_sip_ip}"/> Unfortunately with the above change the system is unable to resolve the dns address and sofia status profile internal' shows Ext-SIP-IP host:myhost.dyndns.org The calls fail randomly because of this. How can i use autonat with the dynamic ip address? Thanks Rajil PS: If i use the dynamic ip address in the the conf file, there is no problem. (<X-PRE-PROCESS cmd="set" data="external_sip_ip=aa.bb.cc.dd"/>)