December 11, 2017Kamailio SIP Server v5.1.0 has been released – this is a major release, meaning that it is introducing a substantial number of new features as well as improvements to existing components.

Overview of new features in v5.1.0

(for more details see the wiki page)


  • Kamailio Embedded Interface (KEMI) framework offers now most of the functions available in the native configuration file. A tutorial is available:
  • SIP Routing Logic can be now written in:
    • The Kamailio native configuration language
    • Lua scripting (with support to reload without restart)
    • Python scripting (with support to reload without restart)
    • JavaScript (with support to reload without restart)
    • Squirrel scripting (with support to reload without restart)

Summary Of New Features

  • nine new modules:
    • acc_diameter – accounting with a diameter server (alpha)
    • app_sqlang – Squrrel scripting interpreter
    • call_obj – track active calls with integer ids
    • evrexec – execute event routes at startup
    • ims_diameter_server – diameter server implementation
    • keepalive – perform keepalive checking against a set of sip addresses
    • phonenum – phone number lookup and normalization module
    • sipdump – write sip traffic and runtime metadata to files
    • topos_redis – redis backend for topos module
  • execute Squirrel scripting code embedded in kamailio.cfg
  • write configuration file routing blocks in Squirrel scripting
    • option to reload updating Squirrelt routing script without restarting Kamailio by issuing a RPC command
    • no dependency of external libraries, the Squirrel scripting interpreter is embedded
  • Diameter Server implementation
  • selective execution of event route blocks at startup
  • lookup a phone number and get its geolocation attributes (e.g., country, operator)
  • topology hiding with sharing data via Redis server
  • support for Redis cluster
  • pipeline support for Redis commands
  • latency statistics for dispatcher and load balancer
  • parallel forking routing algorithm for dispatcher
  • consistent set of improvements to IMS/VoLTE extensions
  • many new config variables in pv module
  • rtp recording capabilities to rtpengine module
  • support to control if data should be sent once the TLS connection is established via an event route
  • event routes to decide if topology hiding should be done with topoh or topos modules
  • options to control to the config variables cache
  • support to reuse tcp sockets
  • internal support to bind on non local ip
  • new commands for kamctl tool

Project achievements during v5.1.0 development cycle

  • the development of the project continued along the 17th year of activity
  • it is the 19th public major release in the history of project (SER project went out first with v0.8.x)
  • the project is about to organize the 6th edition of its own conference, Kamailio World, (May 14-16, 2018, in Berlin)
  • many presentations at events world wide: Astricon, Cluecon, Fosdem, ITExpo, TAD Hack, Mobile World Congress, FUSECO Forum, Berlin5GWeek, Call Center World
  • continuous development at high pace – the project has over 26500 commits to the master branch (over 1800 commits done for v5.1.0 alone from more than 60 different contributors)

Downloading v5.1.0

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 events around the world, of course, Kamailio World 2018 among them, and invite you to join the efforts to improve Kamailio!

Note: Kamailio is the continuation of the former 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 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 Starting with version 4.0.0, SER has been absorbed in Kamailio flavour, which became the default distribution of the project.