On December 04, 2013, Kamailio (SER) SIP Server v4.1.0 has been released – this is a major release, bringing out many new features and improvements to existing components.

Overview of new features in v4.1.0

(for more details see the wiki page)

  • eleven new modules: app_java, auth_ephemeral, cnxcc (prepaid engine), dnssec, gzcompress, ims_charging, mohqueue, rtpproxy-ng, sctp, sipt, stun
  • support for SCTP transport layer and DNSsec are now dedicated modules, allowing straightforward activation, without a need to recompile the SIP server
  • new specific config file tools for handling of SIP-T and SIP-I
  • embedded Java interpreter exposing a Java programming interface inside configuration file
  • ephemeral authentication suitable for WebRTC
  • new RTP relay control module allowing to interact with mediaproxy-ng, which can do encryption/decryption for WebRTC to classic SIP phones
  • compression and decompression of SIP and HTTP message body that helps to save bandwidth or get below UDP MTU size
  • prepaid control engine, allowing to set call limits on credit or time and group calls on credit profiles
  • music on hold queuing system
  • dialog based CDRs in database and customization of time value for accounting records
  • XAVP management via Lua API
  • per module debug level with option to change the value at runtime
  • DNS operations in configuration file – do DNS query on hostname and access the result via config variables
  • export more information via SNMP
  • distributed message queue polishing and replication of hash tables content
  • per branch failure routes, allowing faster subsequent re-routing
  • support for asynchronous processing of SIP responses in configuration file
  • new operating mode for usrloc – dbreadonly – read records at startup, but don’t update them in database at runtime – can be done by a dedicated SIP server that receives replicated registration traffic, improving the speed of SIP routing servers
  • execution of an event route for traffic that generates initial parsing errors – good for automatically blocking the source IP
  • plugin-like support for kamctl to be extended with new commands
  • detailed list of additions is very long, duplicating the content here making no sense, therefore head to read the dedicated wiki page:

Project achievements during v4.1.0 development cycle

  • the project organized its first dedicated event, Kamailio World, with participants from 5 continents and selected group of speakers, resulting in a tremendous success. The second edition has been announced for April 2-4, 2014, in Berlin, Germany
  • development team had a significant growth, four of the new modules in this version were contributed by new developers and few other long standing contributors became official developers
  • there was a rich participation to world wide events such as LinuxTag, Astricon, Cluecon, Elastix World, VoIP2Day, ITSPA, WebRTC Conference & Expo, WebRTC Summit, DevCon5

Downloading v4.1.0

You can download the tarball of the released sources at:

Binary packages for several distributions can be found at:

Packages will be uploaded as soon as they are built by developers (Debian and Ubuntu debs as well as RPMs for Centos, RedHat, Fedora and OpenSUSE) or submitted by community for other operating systems.

A step by step installation tutorial is available at:


Useful links:

Many thanks to those contributing with code, helping testing or advocating the project!
We are looking forward to meeting many of you at next Kamailio World Conference!


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 continued to use OpenSER name. Project site and SVN repository on SourceForge.net still use the old name OpenSER. Source code since release 3.0.0 (when the merge of source code trees of Kamailio and SER was completed) is hosted on GIT repository at http://sip-router.org. Starting with version 4.0.0, SER has been absorbed in Kamailio flavour, which became the default distribution of the project.