YXA SIP software

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 incoming SIP requests to your domain
    • Handles routing of requests from your users to remote domains
    • TCP, UDP and TLS (including SIPS) support
    • Automatically maps e-mail addresses of your users to their SIP addresses, if you have the e-mail addresses in LDAP
    • Handles multiple domains using a single server instance
  • ENUM support for PSTN-bypass whenever possible
  • IPv6 support
  • Forking, both parallel and sequential
  • CPL (RFC3880) support for advanced user-control of events (currently incoming calls only)
  • Modular user database, currently with LDAP, Mnesia, MySQL and text-file backends
  • PSTN destination access control (per user or for anonymous users)

Project goals

  • To create a robust SIP server/stack capable of serving tens of thousands of users
  • Scalability through the use of distributed operation
  • Short time-to-market for new functionality (high-level programming language)
  • Interoperability through standards compliance


2010-03-30: YXA source code is now hosted at GitHub, and I'm preparing for a 1.1 release.

2007-11-05: YXA 1.0 is released! Two years after the first stable release, a very stable and mature SIP server is available. Enjoy.

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