Having grown well beyond its humble beginnings as a personal project, the Asterisk open source PBX turns 10 this month and currently has more than 400 contributors.
Asterisk was first released in October 1999 and now claims some two million downloads for this year alone -- up from 1.5 million last year.
In its early years Asterisk attracted contributors out of interest, but nowadays large companies are getting behind the project with specific needs. And the place where Asterisk is making most in-roads is with replacement of incumbent systems and businesses getting started with IP telephony.
According to research by the Eastern Management Group, in the US open source as a whole was the number one supplier of VoIP lines for 2008 and Asterisk was number two behind Nortel. And Asterisk claims just under 90 per cent open source PBX market.
The project’s founder, Mark Spencer, now runs Digium, a company that offers services and support around Asterisk. Digium now employs 12 developers to work on Asterisk full-time. In this interview, Spencer looks back on 10 years of Asterisk and discusses the future direction the open source product and the VoIP industry in general.
Firstly, congratulations on 10 years of Asterisk. What were some of the high and low points of its development over the past decade that you remember?
It’s hard to take low or high points, because it is about how Asterisk has evolved. It used to be that most work on Asterisk was done outside the company, but now we have hired people to work on it and it’s closer to half-and-half. The open source development model was used from the start, but it’s not what our business model was based on.
What are some of the interesting contributions to the code base Asterisk has had over the years?
If you expand it over the years it has been a lot of incremental improvements. We have gotten some really 'out there' contributions, like one which was an alarm signal receiver. We also had a driver for Cisco’s Skinny protocol contributed, a Nortel driver, and IPv6 support.
The big ones like IPv6 are now collaborative efforts, as they need help getting it really right. There is a lot of work we do assisting contributors in getting the format correct for integration with Asterisk.
Are you surprised at the range and level of interest from individuals to large corporations?
Yes, and in a way it makes a lot of sense. Being open source, Asterisk tends to get people involved from everywhere because it can do so much. When Asterisk came out there was really nothing out there for people to use. So it was an incredible resource for people.
How do you think the advent of Asterisk changed the way traditional proprietary, hardware-based PBXs are developed?
For better or worse, when I created Asterisk I didn’t know how PBXs worked, so I made Asterisk operate in a way that was very different that other PBXs worked. So that was why it changed things -- because people who didn’t know how to use a PBX used Asterisk because it was built in the way something like Apache was, for example.
Asterisk was more like the way people -- and particularly IT people -- expected software on Linux to work.
The downside was that it took a lot longer for people who were used to their phone systems to get the Asterisk approach. As an approach, it was not without its negative side effects, but it was the best way for the audience we were going after.