Dear Kamailians, Sorry for double posting, after joining the mailing list. I have Kamailio+rtpengine as a dispatcher in front of FreeSWITCH. Kamailio and FreeSWITCH are on the same private network (in an AWS VPC). Kamailio receives calls on the Public Internet IP address and port, and dispatches to FreeSWITCH on the private network. All calls are coming from a SIP Trunk provider, from the Internet so no NAT on this side. My Hello World scenario is: FreeSWITCH answers the calls, plays a media file and disconnects. Problems: 1) In the INVITE relayed from Kamailio to FreeSWITCH, I can see a Record-Route with the public IP of Kamailio. Hence, the BYE sent by FreeSWITCH is sent to this public IP, rather than going back to the Kamailio path, and the call never gets completed from the caller's point of view. I tried adding record_route() in request_route{} but nothing changes. 2) The SDP part of all the messages coming back and forth from Kamailio and FreeSWITCH all contain the correct private IPs, but still the media file can't be heard on the caller's side. Is RTPengine correctly bridging the RTPs? Kamailio configuration is here: https://gist.github.com/eravelo/b3f026723e27d42354804ef942b34a04 Rtpengine configuration file has: [rtpengine] table = 0 interface = internal/10.20.1.158;external/10.20.1.158!KAMAILIO_PUBLIC_IP listen-ng = 127.0.0.1:2223 timeout = 60 silent-timeout = 3600 tos = 184 port-min = 16384 port-max = 32768 Your help is appreciated. Thank you. Eric R.