Friday, December 22, 2006

Kamailio (OpenSER) Summit 2006 - OpenSER IMS

IMS (IP Multimedia Subsystem) couldn't miss such event. Seen as evil for the freedom of IP world, the way Telcos can restrict mobility, or, actually, to charge for it.

Joachim Fabini of Technical University of Vienna, shared his experiences while implementing a OpenSER-based IMS in CAMPARI project (interesting concept: IMS in a bottle). Along with the architecture and components, very valuable were his conclusions and thought about IMS and future directions of VoIP, where the mobile communication will meet IP world and directions to be approached to ensure success.

A very interesting result of this experiment was that they used Kamailio (OpenSER) barely as it is, with no hacking, IMS components being Kamailio (OpenSER) instances with different config file. The work was a proof of concept, optimization could be brought by code writing.

Download slides of OpenSER IMS.

Kamailio (OpenSER) Summit 2006 - Practical Peering with OpenSER

When comes to peering, the hot word about is 'security'. How trust able the other party is, how can you ensure safety and security for your subscribers. Many VoIP services are isolated islands, walled gardens. This is not something most of VoIP fans look for, they want freedom and ability to talk with people around the world, no matter of VoIP provider.

One solutions is federation, alliance between VoIP providers sharing the trust relationships. Klaus Darilion from introduced such solution in Kamailio (OpenSER), based on domain policies and secure communication via TLS.

The management of trustable federations and domains become more flexible and dynamic. The slides are going to low level of technical aspects to exemplify such configuration with Kamailio (OpenSER).

Download slides of Practical Peering With OpenSER

Monday, November 27, 2006

Kamailio (OpenSER) Summit 2006:, an open VoIP community, nominated in "The 50 Most Influential People in VoIP". It is known for its web forum, free VoIP service based on SIP, plus their reviews of VoIP devices, books and services.

It is pretty much impossible to reproduce Dean Elwood's speech, you just have to get the opportunity to listen to him. He is a lawyer day by day and his hobby is the VoIPUser, but I felt the opposite. He co-founded with the aim of building a place for "experimenting new stuff". And they did test and experience lot of stuff out there, they built one of the biggest web forums in this area, with a good knowledge base. Many came to the forum as newby and are able to help to others questions in short time.

Still the main goal is to experience new stuff. Privately, he launched an open invitation to for OSP testing. They have available an OSP server, if someone else is interested can drop a message on the forum or send and email to us at <team (at) kamailio (dot) org>. Several plans are to be shaped to touch new stuff and open ways in VoIP and to involve many people and open source projects in such collaborations.

Download slides of

Kamailio (OpenSER) Summit 2006: Truphone - Reversing The Paradigm

No other new service in the last year rose so much rumors in the market as Truphone ( did since its beta launch at VoN Autumn America, Boston, 2006. It was not just a new VoIP service like many others in these years, they brought something people spoke about in the past, but was mainly behind the scenes: VoIP over mobile network. And it is not voice channel replacement, but convergence between fixed and mobile networks, between SIP and other IM/VoIP protocols out there -- this is more than what VoIP did to fixed lines in the past, and could open a new era for mobile communication.

Googling will reveal lot of comments about Truphone target and its features, which makes no sense to repeat here. You can just make an account and test it by yourself.

I will underline only one idea presented there: what is behind the service. Basically the Truphone VoIP platform is pure open source. Database server, web server, sip server, media server, operating systems. Isn't it a bit mad to do it so? Well, seems not, the platform was built starting with March 2006 and in about 6 month was able to run in beta mode, while a lot of efforts were conducted to develop client side applications, web interfaces and many bits and pieces for transconding, handoff and interoperability.

Would a vendor (even the big ones) be capable to deliver a solution for a brand new business model in such time frame? James Body, Director Networks Truphone, spoke enthusiastically about the flexibility and power of open source: how one can combine and get best out of it for a solid business.

Download slides of Truphone - Reversing The Paradigm

Sunday, November 19, 2006

Kamailio (OpenSER) Summit 2006: High-availability environments with geographic redundancy

VoIP at large, how and why? For a company having almost 40 years experience in telecommunication technology, the maturity of products and solutions when dealing with big operators are essentials. Scalability, flexibility and more important, availability, are main requirements.

Benjamin Wolf of Basis Audionet introduced their solution for a HA VoIP platform, worked for Telcos requirements. It is not only Kamailio (OpenSER), it is hardware and software which combined give the reliability one needs for such cases.

Besides the debate of title's topic, the presentation emphasized middleware and components of distributed VoIP systems.

Download slides of VoIP High-Availability Environments With Geographic Redundancy

Kamailio (OpenSER) Summit 2006 - WeSIP & SIP Application Servers

Most innovative solution so far developed by third party to work together with Kamailio (OpenSER) was presented for the first time to the public by Voztelecom: WeSIP. CIO Ginez Gomes gave a comprehensive overview of SIP application technologies and why SIP servlet and J2EE allow providers to develop easily new services to attract and secure customers.

It is rather new technology with no many investigating in this direction until now, but since VoIP did lot of first line replacement, something else should ensure further the success of VoIP services. As it happened with HTTP, at the beginning was pure HTML display, mainly oriented to static information sharing. Today even simple sites have dynamic content, with web applications behind, running Java/JSP/Servlet, CGI/Perl/PHP/ASP, Flash, Ajax and others. This came after several years of www, so same comes now to SIP/VoIP.

I am basically pure C programmer, but I salute such initiative and we will try to help as much as possible to get it integrated properly in OpenSER. Making the connector part of OpenSER as module is the first step in creating a proper environment for such extensions.

Main outcome of such solutions is the merge of SIP routing flexibility in OpenSER with enormous programming facilities of Java. Enterprise API as EJB, JDBC, JNDI, SOAP can be used to build quickly on brilliant ideas.

It was required deep knowledge of protocols and low level network communication skills to work on this area, by opening the horizon to application level programmers, the VoIP will burst its business space. Time will prove which technology for VoIP applications is the best, but is no doubt that applications will lead VoIP's future.

Download slides of SIP Application Servers And WeSIP

Kamailio (OpenSER) Summit 2006 - November 8

Day before we met many Kamailio (OpenSER) folks at VoN party, chatting around some beers for long time, interesting visions and opinions about VoIP: SIP, P2PSIP, other VoIP systems: Skype, Yahoo... After midnight we left for hotel, we had to be at least one hour before the summit started, to prepare the room . The hall was bigger enough this time, with over 90 places for attendees.

First hour was dedicated to accommodation, coffees and tees, introduction to agenda and OpenSER History. During it, people assembled in the room, so when the first industry perspective started the audience was good. In the last minute we get Olle E Johansson to speak about OpenSER and Asterisk in the open discussion panel.

For statistics, we had 12 speeches and over 20 special guests, including the speakers. Time was rather short for what everything wanted to present, the schedule included a long break for lunch and Expo visit. We had to prolong both morning and afternoon sessions to cover everything planned. Considering that many from the audience stayed to the end (others had to leave some time before to catch the flights), my personal opinion is that what was addressed there gathered good interest.

From the OpenSER management board, the only missing was Juha Heinanen who couldn’t change his plans to be able to attend.

Download slides of
OpenSER Summit 2006: Agenda and OpenSER History

Tuesday, November 14, 2006

Kamailio (OpenSER) Summit 2006 - BoF Session

Birds of a Feather: Kamailio (OpenSER) for Secure and Performant VoIP Environments - was the short session opening the summit on the 7th November. The location was the Expo theater, a hall rather small, targeted for exhibitor's briefings of new services or products.

Since most of our attendees registered from the first day, the seats were not enough, some had to sit on the floor or stand up. This was quite inconvenient for all and we should look for a better organizing in the future.

The scope of BoF was to give a quick shoot about Kamailio (OpenSER), like a preview of the next day, but not only. We tried to bring in discussion concepts, exemplifying with some implementations when was the case.

The moderator was Xavier Casajoana, CEO Voztelecom, who had to talk instead of Jesus Rodrigues as well, who's flight was delayed. Therefore, he presented interesting views over hosted services and how to make such business successful. He underlined that replacement of first voice line is outdated in VoIP and the key is the innovation, to bring adjacent services and applications. Other major benefit of hosted services is the immediate roll out of the service, there is no time needed to set up the VoIP platform, you just have to label an existing one.

Actually the first presentation was about SIP services in distributed environments, by Bogdan-Andrei Iancu. Laying out distribution types in VoIP, his talk focused on reasons and implications of such deployments. What can be distributed and for what reason, when someone should start concerning about distributing his VoIP system and where to look for, all those where spotted in the speech.

The slot about 3/4G and convergence was held by James Tagg, Managing Director Truphone. Already experienced in this area, the Truphone service bringing VoIP to mobile phones is launched in beta stage since VoN Boston, he addressed the benefits for users and the merits of open source IP telephony applications to apply quickly new ideas.

Of course ENUM couldn't miss the debate. The fight for ENUM control delayed its adoption. Klaus Darilion,, spoke about new concept of infrastructure ENUM that will enable carriers to apply the requirements they must have is this kind of business.

Ending speech was about peering with heterogeneous networks. Daniel-Constantin Mierla, co-founder OpenSER project, revealed numbers about subscriber base of other IM/VoIP networks, motivating why they cannot be ignored or isolated. The solution is to interoperate with them, adding value to your service. The main focus in short term is XMPP interoperability (Jabber,GoogleTalk).

The questions slot started with OpenSER vs. Asterisk. Bogdan cleared it by explaining they are complementary, not overlapping. I presented shortly the steps done so far for an easy integration of Kamailio (OpenSER) and Asterisk, tutorials being available on and dokuwiki from

Someone insisted in getting a good solution of serving 100 000 000 users with a OpenSER+SS7 system. SS7 is not a primary target for OpenSER as it was designed to work at signaling level, to be hardware independent and not deal with media stream. All panelists gave alternative solutions for such large deployment and technology requirement.

Other question was about Enum's heavy process of adoption. Overall conclusion of Klaus was that improper legislation and the carriers not seeing direct benefits with current standardizations made the adoption rather difficult.

Download slides of BoF: Kamailio (OpenSER) - for secure and performant VoIP environments

Friday, November 10, 2006

Kamailio (OpenSER) SIP Server

This blog was started with the main reason of publishing articles about Kamailio (OpenSER) SIP server, an open source GPL server implementation having lot of features and being widely used over the world. Just check project's web page for more details:

I just returned from Berlin, Germany. We had great time there during first Kamailio (OpenSER) summit hosted at VoN Autumn Europe. Lot of Kamailio (OpenSER) users attended the events and the time was too short to speak to each other.

The overall conclusion and feeling about the event was very good. A very nice surprise was the number of attendees, who heroically resisted to the end of slides marathon -- we were the last leaving the conference center. The diversity of solutions and use cases presented there made the time to flow faster.

Photos and slides are available on site:

Soon will follow comments about each presentation, since the slides do no reflect entirely the speech.