By Henrik Ingo on May 23, 2008
During 2008 we are planning to run a series of interviews with interesting persons somehow related to the telecom field. In this first installment, we will have a chat with Juha Heinänen from Finland.
MySQL: Juha, you are a former professor of Computer Science and Communication technology, CTO (or similar positions) in at least Sonera, Telia and Song, former ATM specialist, responsible for bringing Internet to Finland and registering the .fi top-level domain, a consultant for many early network equipment startups some of which succeeded to be still with us today, and author of several RFC's. Nowadays you are a core contributor to the OpenSER SIP proxy, and you sell a VoIP platform called OpenSIPg based on that to Nordic operators. In addition you seem to live a life that would likely be a dream of many hackers, spending time in different parts of the world hacking on your favorite Open Source project. Even to this date, I don't think we've ever met in person.
MySQL: For many years now you have been working with the SIP protocol and OpenSER SIP Proxy. When did you first turn your eye to SIP and why did you become
interested in it?
JH: When working for Song Networks (now TDC) in late 1990 and early 2000, we saw a need for a hosted VoIP service for small businesses. Due to my IETF background, a natural protocol choice for me was SIP instead of the then dominant H.323. At first, we trialled a Swedish commercial SIP proxy called Hotsip, but didn't find it flexible enough for our purposes. I then heard about an Open Source SIP proxy project called SER, saw its great potential, and soon became a SER developer although I had not written a single line of code during the past 10 years.
MySQL: Knowing that you enjoy coding, it must have been great to return to it! By the way, what is your short, 2-3 sentence introduction to OpenSER?
JH: The OpenSER project is a spin off of the SER project. Our aim in OpenSER is to bring to the market a well tested new release of OpenSER SIP proxy every 10 months or so. Today OpenSER is a very successful project with many of high quality developers and a wide user community.
MySQL: How do you see the Internet vs the traditional telephone network? Will SIP (or some other Internet based protocol) eventually completely replace the Plain Old Telephone System?
JH: This is hard to answer, because there always exists the "dark side" that wants to retain the old walled garden style POTS service no matter what equipment or protocols they internally use. These people see telephony as something special, not just yet another Internet application.
MySQL: I remember once talking to you, that you were furious about an operator who insisted on you to implement minute based billing for OpenSER :-) I guess you never did that for them?
(Note to readers: Not that you would consider this for any other Internet protocols either, but this kind of requirement is especially ridiciluous for a peer-to-peer protocol like SIP, since most of the data in a VoIP call may not route through the operator network at all, so it would be hard to justify the operator charging for traffic that is actually happening in some other operators network!)
JH: I don't recall this, but time based billing of SIP calls would be very difficult to implement without also getting involved with routing of media. That, in turn, would mean that most of the advantages that SIP based telephony has over POTS would be lost.
MySQL: What do you think about the IP Multimedia Subsystem?
JH: IMS is a next generation implementation of walled garden telecommunication services. I let it live its own life. I don't care if some users are too rich or lazy and choose IMS instead of open Internet based services as long as I'm not forced to do so.
MySQL: What will happen to service providers (mobile and fixed)? Especially as VoIP companies provide much cheaper calls. And web companies like Google are
offering services. Will the carriers be reduced to bitpipes?
JH: Mobile or fixed Internet access is always worth the money and I gladly pay for it. What I don't like is when operators start to milk their cows without providing any real added value, e.g., by charging huge roaming fees for mobile Internet access. It is operators' own choice if they let companies like Skype and Google take away their customers by not providing their own Internet based telecommunication services.
MySQL: Or asking the same question differently, who will eventually be our service provider for voice calls? Google, Nokia, my current telecom operator, or the current VoIP service providers or maybe some decentralised non-commercial and free peer-to-peer VoIP network?
JH: To me telephony is just yet another Internet application. The same parties will be providing it in the future that today are providing email, web, etc. services. In case of my own company, TutPro Inc., it is TutPro Inc. itself, because I don't like the idea that someone else (perhaps with ties to government spy agencies) is storing my emails or routing my VoIP calls.
MySQL: What is your view on convergence? Or even simpler, what is convergence?
JH: Convergence is a term that I don't fully understand. My goal is to be able to use Internet for all my communication needs. What prevents it from happening today is too slow and (sometimes) too expensive mobile Internet access that is unsuitable for real-time communications.
MySQL: So, tell us more about your current projects. What are you working on now?
JH: I have OpenSER and SEMS based SIP platform called OpenSIPg that a few operators and organizations in Finland and Sweden use to offer their VoIP and presence services. Developing OpenSIPg keeps me busy, but thanks to mobile Internet access, does not tie me physically to some particular place or country.
One new thing that I have been working on is a simple, certificate free mechanism for reliable verification of trusted peers. It is based on Radius protocol and a broker model similar to what was used already long time ago for dial-up access.
MySQL: I know you recommend MySQL Cluster to your customers as the database to go with OpenSIPg. What is the database mainly storing, and what features make MySQL Cluster the best fit?
JH: Well, firstly OpenSER SIP proxy keeps all location and presence data in MySQL database tables. My own principle in developing OpenSIPg has been that my customers should not need to edit any text files when they provision users or the VoIP infrastructure itself. So all OpenSIPg information is kept in MySQL databases, where it can be accessed and manipulated via web based GUIs.
The databases should naturally be resilient and therefore a clustered implementation is the best fit.
MySQL: By the way, for the more technical readers, do you have any kind of numbers about the loads OpenSER and the database behind it must support? Like calls per second or SQL transactions per second? (I know the Finnish operators are not the biggest in the world, but still.)
JH: None of my customers have hit or even been close to any performance limits yet. Nevertheless, a good SIP proxy design tries to minimize the number database operations that need to be performed per request. We thus recommend MySQL cluster more for high availability rather than performance reasons.
MySQL: If you had 3 wishes - but restricted to MySQL Cluster - what would you wish for?
JH: I would wish that MySQL 5.1 would become available also as Debian/Ubuntu packages, because cluster capabilities in 5.1 are more developed than those in 5.0. From maintenance point of view it is not a good idea to install any software to servers from tar files. My other wishes are related to ease of use. Setting up and running MySQL cluster should not require a high degree in database administration.
MySQL: So let's see, your product is based on Linux, OpenSER, PHP, FreeRADIUS and MySQL. What is the importance of Open Source in Telecom? What can Open Source do for Telecom?
JH: Open Source is important for everyone. Large developer and user communities of Open Source software can produce rapidly higher quality software than even the biggest companies can do on their own.
MySQL: Years ago, we had an email chat about a mobile application that was using SMS messages to communicate with a server. Your quick comment was: "Nice, if you want to use such legacy technology." As the pioneer spirit you are, where do you see the border between "legacy" and "modern" in 2008?
JH: I think I was referring to SMS as "legacy" technology because SMS was not terminal and underlying network independent Internet application. That is still true today and for some strange reason even Nokia has not yet made SIP based messaging available in its phones.
MySQL: And what will be legacy in 2011?
JH: I'm afraid that in 2011 there still exist mobile network specific services that do not work end-to-end unless each mobile operator has made a bilateral agreement with each other mobile operator. Such a service model simply does not scale nor lead to rapid development of innovative services.
MySQL: Thanks Juha for taking the time to talk to us, it has been a pleasure. And all the best to your future projects.