On October 06, 2010, Kamailio (OpenSER) 3.1.0 has been released – this is a major release that includes an large number of improvements and new features, as a result of development from Kamailio (OpenSER) and SIP Express Router (SER) teams.

Backed up by the knowledge and work force of the two teams, development power boosted the amount of new functionalities. We are proud to announce over 15 new modules and many major additions – for first time available on the market: asynchronous TLS, UDP raw sockets, embedded Lua, interactive configuration file debugger and many more you will find in this announcement.

Since last major release, version 3.0.0 (which was out in January 10, 2010),  the two SIP servers are practically the same application, the name making the difference regarding the database structure and the extensions used for certain features, such as user database based authentication or location service. Therefore another development direction was towards smooth integration of Kamailio and SER extensions, previously duplicated modules such as auth, sl, ratelimit or sms were merged during this development cycle.

Here is a summary of new features in v3.1.0 (for more details see this wiki page):

  • refactored default configuration file with many new functionalities included
  • asynchronous TLS – no longer performance penalty when dealing with heavy TLS SIP traffic
  • UDP raw socket support for Linux – 40-50% faster than normal UDP
  • interactive configuration file debugger – step by step execution of configuration file and print of execution trace
  • embedded Lua – execute Lua scripts in configuration file
  • embedded Python – execute Python scripts in configuration file
  • embedded HTTP server – handle HTTP requests sent over SIP channel or dedicated port
  • embedded XCAP server
  • extended define pre-processor directive support in config file
  • new subst pre-processor directive for string substitution
  • enhanced default configuration file with support for TLS, DoS attacks detection, XMLRPC handling
  • GeoIP API in configuration file
  • asynchronous message queue in configuration file
  • tree-indexed generic cache systen
  • handling presence notifications from audio conference mixers
  • SIP registration to remote servers
  • new internal statistics API
  • stand alone accounting to radius module
  • refurbished least cost routing
  • load balancing based on weight or call load with dispatcher module
  • database-driven SIP traffic shaping policies
  • reason header support (RFC3326) for CANCEL
  • many function parameters accept now directly expressions, not only string values
  • several modules coming from both Kamailio and SER were merged (sl, auth, sms, ratelimit)
  • new command line option to handle defines and auto-aliases
  • enhancement to related tools such as kamctl, sercmd and siremis

More details about what is new are collected in New in 3.1.x Wiki Page

Important note:


You can download the tarball of the released sources at

Binary packages for several distributions you can find at

Packages will be uploaded as soon as they are submitted.


Useful links:

Note: Kamailio is the new name of OpenSER project, name changed on July 28, 2008, due to trademark issues. First version under Kamailio name was 1.4.0. Older versions will continue to use OpenSER name. Project site and SVN repository on SourceForge.net still use the old name OpenSER. Source code for release 3.0.0 is hosted on GIT repository at http://sip-router.org.