Wednesday, May 30, 2012

Remarks about Kamailio at LinuxTag

The participation of Kamailio at LinuxTag this year was filled with several related events and, as usually, a great opportunity for community meeting and social networking.

Again, five of the management team members were at the booth in various occasions, answering questions and making demos: Andreas, Carsten, Daniel, Henning and Ramona. Marius and Mario from 1 & 1 Romanian branch and Germany completed our staff. We shared the space with related SEMS project, Stefan, Rafael, Vladimir and Alena being there for it.

On Wednesday, Carsten had his presentation in the LinuxTag Conference track, Daniel did the Project Fast Forward presentation at Open Source Arena. On Thursday, Daniel gave one hour workshop about how to install Kamailio and configure it for secure unified communication services – a well received event, the seminar room being fully attended. On Saturday, the Project Fast Forward presentation was repeated by Daniel. Links to presentations:
Most of visitors were from Germany, but we had several people coming from neighborhood countries, like Poland and Denmark.

We learned about interesting deployments using Kamailio, notable being a relatively large Instant Messaging and Presence communication platform, using the SIP SIMPLE presence modules (including RLS) – the average online user base being 40 000, with peaks at 60 000. Out there are much more larger Kamailio deployments, but mainly targeting telephony services. This deployment proves that SIP SIMPLE presence extensions are becoming more and more an attraction, not being a dead direction. Our upcoming Kamailio v3.3.0 has a lot of improvements in scalability of presence related modules, which along embedded XCAP server and MSRP relay modules, makes Kamailio the most complete SIP SIMPLE implementation out there.

Now LinuxTag 2012 is gone, time to focus on the release of Kamailio v3.3.0!

Tuesday, May 29, 2012

Planning for Kamailio v3.3.0 Release

The volume of reported issues on mailing lists and tracker has been close to zero lately, suggesting that upcoming Kamailio v3.3.0 is going well. Therefore it’s time to set the timelines for the new major release – by now there is more than one month since the development was frozen and testing phase started.

In my side, I (Daniel-Constantin Mierla) have 3.3.0 running in a production-like environment for about 4 weeks without problems and another one in a pre-production phase.

Having in consideration all these, the proposed date to branch 3.3 is set to June 11, 2012. If everything looks very good at that time (or actually few days before), we may do the release also by that date or next day. If not, it can be done a week later.

Branching will allow new features development on git master, there are already several contributed patches with new features flowing around on mailing lists and tracker.

Therefore, if you are aware of any issue, please report asap on mailing list (sr-dev [at] or tracker (preferable –

Other suggestions about planning the release 3.3.0 are welcome, as well.

If you want to check the draft of new features in v3.3.0, see:
Testing and feedback is very appreciated!

Friday, May 25, 2012

Kamailio and SEMS in a Risk-of-Life Service

An interesting story sent by Jeremy A. on SEMS mailing list about use of Kamailio and SEMS in emergency services.

This is a belated report on the use of SEMS in a risk of life service.

The system uses Kamailio in a distributed architecture of dozens of Fire & Rescue stations. This is heavily based on distributed and replicated DNS.

A single ’911′ style headquarters has duplicate hot swap-over control rooms at other locations.
The headquarter and alternate posts have servers that service HQ operator positions with SIP phones. These provides sidecar indication of F&R Station state for up to 64 F&R stations – using BLF. These phones are hooked into an integrated analogue audio management system.

Each Fire and Rescue station has an embedded SIP based controller that runs Kamailio and proprietary software to control the F&R station electrical and safety systems as well as provide public address functions to alert the F&R staff of a new emergency. These PA announcements are SIP based using a DSL network and are live from the HQ positions, plus computer synthesized voice, as well as alerting tones.

Each station also has multiple SIP phones for in-station and station to station calling.
The network is decentralized, so failure of the central control system still allows point to point communications between Fire and Rescue stations.

The headquarter systems uses SEMS as the primary operator manager to perform multiple simultaneous deployment calls to remote Fire and Rescue stations. SEMS is used to create a dynamic conference between an operator and multiple Fire & Rescue stations. These are automatically initiated by SEMS and answered by the F&R embedded systems. This means an operator can broadcast a deployment message and initiate station control activities at up to five stations (fifth alarm) This is only constrained by the bandwidth available at the headquarters. Our SEMS packages have been designed to handle non-answered calls to the conference and provide operator indication by ‘SMS’ messages to the handsets and audio feedback.

The system provides full forensic recording by using rtpproxy at all locations. These recordings are archived by an out-of-band process.

Control of the system is purely SIP based – so every item in the system is a SIP based entity. This includes servers, embedded systems, and phones.

The phones are physically integrated into operator positions that also handle PSTN, PBX, and radio traffic. The interface is purely keyboard on the operator phones.
Options for integration of the SIP system into CAD (Computer Aided Dispatch) are obvious. The only drawback is the rusty and ancient systems and the unbelievable process required to get approval to integrate.

The system as provided provides at least 5 nines reliability. Probably a lot better. The only downside is the DSL network (provided by others at amazing expense) that provides a system with a lousy 2 nines reliability. We are in the process of developing an offering using redundant DLS/3G routing to improve this.

The field stations are a hybrid Centos 5/Slax system running out of flash. The HQ systems are straight Centos 5 systems running off disk or off flash. Future versions will be pure Centos out of flash with no fancy memory overlay – flash is well good enough.

The system has been live for over a year with no major issues. I can’t say how many lives have been saved, but certainly quite a few. At least we haven’t been sued yet!

Wednesday, May 16, 2012

LinuxTag Workshop: Building secure UC service with Kamailio

Daniel-Constantin Mierla (n.r. the blog owner), co-founder and member of management board for Kamailio project, will provide one hour workshop during LinuxTag Conference & Exhibition, Berlin, Germany. Scheduled on Thursday, May 24, 2012, the workshop will focus on how to build yourself a secure unified communication platform, using Kamailio in server side and Jitsi as application in client side.

You can read more about the workshop at:
As you get at LinuxTag show, just drop by at Kamailio project booth to have a chat, you can meet five of the management team members, along with other developers, community members as well as the friends from SIP Express Media Server (SEMS) project. The booth is located in Halle 7.2b, Stand 278.

Monday, May 14, 2012

LinuxTag Talk: Rich Communications using SIP and Kamailio

Carsten Bock, developer and member of management team for Kamailio project, will give a presentation at LinuxTag Conference & Exhibition in Berlin. The date of the talk is Wednesday, May 23, 2012.
Scheduled about noon, you can learn how to use Kamailio build platforms for providing RCS/RCSe and IMS-based services (communication beyond voice using SIP – instant messaging, presence, IPTV, a.s.o.).
You can read more about the presentation at:
As you get at LinuxTag show, just drop by at Kamailio project booth to have a chat, you can meet five of the management team members, along with other developers, community members as well as the friends from SIP Express Media Server (SEMS) project. The booth is located in Halle 7.2b, Stand 278.

Tuesday, May 8, 2012

SEMS v1.4.3 Released

On the 4th of May, 2012, the SIP Express Media Server project announced the availability of the SEMS 1.4.3 release.

This is a SEMS 1.4 series bugfix release and should be a drop-in replacement to 1.4 installations. For details of the changes see:
Sources are available at:
More about the project:
SEMS is a project tight related to Kamailio, started at the same institute in Berlin, Germany, having many shared developers. It can be used together with Kamailio to provide services such as voicemail, audio conferencing, announcements, IVR menus or back-to-back user agent functionality.

Monday, May 7, 2012

Kamailio Project at LinuxTag 2012

Kamailio project will be present with an exhibition booth at LinuxTag show in Berlin, Germany, May 23-26, 2012.

If you visit the event, drop by stand 278 in hall 7.2b and have a chat with members of management team, developers or other community members. You can see demos of services and solutions from companies such as Asipto, NG Voice or Sipwise.

SIP Express Media Server (SEMS), a sister project, will be collocated with us, giving you the opportunity to learn how to use it together with Kamailio in order to provide media services such as voicemail, audio conferencing, IVR menu or back-to-back user agent functionality.