repro servers peer with each other in a federated manner just like SMTP servers for email, but using TLS mutual authentication to prevent impersonation. Kamailio has TLS support and should be able to talk to such servers and other Kamailio servers in the same way. It would be good to create a recommended sample configuration for this type of service and also add it to the RTC Quick Start Guide: http://rtcquickstart.org/guide/multi/sip-proxy.html --- Reply to this email directly or view it on GitHub: https://github.com/kamailio/kamailio/issues/531