How Gtalk2VoIP brings SIP capability to your instant messengers?

We talked about GTalk2VoIP earlier as wonderful solution to SIP-enable your plain vanilla instant messaging client. GTalk2VoIP is an interesting service, bringing SIP service to your instant messenger. If you have not tried GTalk2VoIP, I would strongly urge you to try the service. While the service is great, we were not sure how the folks at GTalk2VoIP manage this feat. However, I was recently able to speak with Mr. Ruslan Zalata, co-founder of GTalk2VoIP, and he was kind enough to share some insights into the service and other technical details about how GTalk2VoIP brings SIP capability to your instant messengers. The interview extract follows (AS – Alok Saboo; RZ – Ruslan Zalata):

GTalk2VoIP_logoAS: For the benefit of our readers, can you introduce yourself?
RZ: My name is Ruslan Zalata, I’m a co-founder of GTalk2VoIP, Inc., one of the developers of GTalk2VoIP service and a piece of mobile VoIP (mVoIP) software called Talkonaut.



AS: You provide a wonderful service in Gtalk2VoIP where you bring SIP capabilities to instant messaging clients. Can you provide more details about the service?
RZ: Sure! We developed GTalk2VoIP service in early 2006 soon after Google had made their Google Talk with Jingle Audio publicly available. The main idea was and still is to provide Google Talk users with an access to outer VoIP worlds like SIP and phone calling. Despite our deep knowledge and large experience of running VoIP (mainly on Ciscos) it was a great challenge for us: first, we had to reverse-engineer Google’s Jingle implementation (it was not published at that time), second, we had to write our own soft-switch from scratch implementing basics of H.323 and SIP stacks. The first version of the service we released in April 2006 had only one feature: a possibility to make paid for phone calls through one of our VoIP termination partner. We started to receive lots of feedbacks and feature requests, mostly asking for adding SIP support, which we shortly did. In a month, we added SIP gatewaying which allowed Google Talk users to make calls to SIP URIs and and vice versa (i.e. SIP users to make calls to Google Talk through a mapped SIP URI). Then we added a possibility to define users’ SIP accounts to make phone calls through them (Betamax clones such as Rynga, ActionVoIP, and SmartVoIP are very popular among our users). Later in 2006 we reverse-engineered MSN voice protocol and added it to our soft-switch and to the service. In 2007 we cracked Yahoo’s SIP challenged which allowed us to add Yahoo into the set of supported IM messengers. In early 2008 we added AIM/ICQ voice support. Despite the large set of supported IMs, Google Talk users are still 90% majority of our service, so we keep focusing on them, adding more and more features for Google Talk.

GTalk2VoIP - SIP capability to your instant messengersAS: Why should users subscribe to Gtalk2VoIP when they can access some of the services through a SIP client?
RZ: “Subscription” is not a proper word for our service as we do not ask users to create new usernames, fill-in endless profiles with personal data, etc. What users have to do to be able use our gateway is just to add service@gtalk2voip.com buddy into their list of contacts (roster). Our gateway auto-accepts such invitation then automatically creates all the necessary records in our database. So, once service bot contact is added user may use all the services we provide right away (except some paid for services which require adding credits before usage of course). Un-subscription is same way easy – just remove service bot contact from your roster.
To answer why people should use our service, I can tell you that majority of Google Talk users never knew what SIP and/or SIP client was, they are using our service because they find it convenient for them to solve their communication needs, they don’t need to install complex, often over-bloated SIP software, which only highly skilled expert can properly configure. GTalk2VoIP service is damn simple: add contacts, make calls. No usernames, no passwords, no extra software to install.
There is one more thing. Our GTalk2VoIP service is very popular in countries and on mobile carrier networks where regular SIP and Skype are blocked. This is a clever hack to access SIP over Jingle.

AS: Can you provide some insight into the technology that you are using to bring SIP capability to IM clients?
RZ: Technically our service is highly scalable, it runs a cluster of distributed FreeBSD servers and satellite VPS relays. The soft-switch part was written in C/C++ from scratch. We also developed our own FSM framework in Perl5 to run FSM for call processing logic, most service features are merely FSM scripts. Billing stuff partially written in Perl5 partially in PL/PgSQL (we run PostgreSQL 8). There’s some brief description of the technology on https://www.gtalk2voip.com/gtalk_technology.shtml.

AS: What is your business model? I see you have some premium services, but I was just wondering if a user just uses the basic free services, how much does it cost you?
RZ: Our business model is straightforward. We charge customers directly (there’s another story how difficult it is with all the credit cards fraud!) for premiums services. The most popular are: calling to PSTN, selling DIDs and User-defined SIP which allows users to use their existing SIP accounts in Google Talk and Talkonaut for small monthly fee. We run a lot many free services as well, including gatewaying Google Talk/MSN/Yahoo/AIM to SIP and back, gatewaying calls between these voice capable IM messengers, gatewaying to SIPBroker and free calling to 1-800 (toll-free) numbers. It’s no surprise that in early days of our service more than 90% of the traffic was made by people who used free services only. Due to the nature of our service, we are forced to relay all the signaling and media traffic through our servers, which hurt us a lot. It took a great effort and more than two years for us to leverage balance between free and paid-for traffic to 60/40 and this is where business comes to the scene. I cannot tell exact figures due to known reasons, but I can tell you that we have a slightly more than 1 million of “registered” users, 10% of them are active, so you can calculate how much traffic it is and how much does it cost (the average freemium user makes 2500 minutes a month). Since November 2008 GTalk2VoIP service is profitable business. The company itself is profitable since the very start as we made quite some revenue on selling our technology.

AS: Who is your biggest threat/competition?
RZ: Well, almost any regular VoIP/SIP provider can be considered as a competitor to us as they may and always do steal our customers attracting them by cheaper PSTN calling rates (like endless Betamax clones). But, as this is not the only paid-for service we offer, so it’s not a much threat to us. What threats us more is that Google may one day block our gateway or stop distributing their Google Talk or decides to shutdown entire XMPP service they are offering for gmail.com accounts. This will damage us a lot for sure and this is another reason why we direct our steps towards our own mobile VoIP solution – it brings independence and opens new markets.

Thanks Ruslan for your responses!! We will continue our discussion with Ruslan in upcoming posts, where we talk about why Google, Microsoft, or Yahoo may not provide SIP service in the future and integration of the SIP protocol in the operating system. Keep looking…

original source