What is YXA? YXA is SIP software written in Erlang (Erlang is a programming language written by Ericsson). YXA is both a transaction stateful SIP stack, and a set of SIP server applications. YXA is Open Source, and released under a three clause BSD license. Main features RFC3261 compliant SIP-server, capable of everything a generic domain needs : Registrar that keeps track of your users Handles in