If someone offered you a complete IP PBX for free, would you take it?

That’s the value proposition offered by telephony open-source software, a new industry segment that is seeing significant growth in deployments by service providers and even enterprises that want customized phone systems for specific needs.

The availability of these open software systems creates new opportunities for integrators and resellers to design and implement custom phone systems for both service providers and enterprises. They usually are not the phone-systems-in-a-box as they are sometimes portrayed, but the software packages are becoming more stable and refined by the day. They require some expertise, but they open new doors for the integrator who takes the time to learn the software.

“It’s still a young industry, and there is still some skill involved in this and at a higher level than traditional telecom VARs,” says Richard Bodo, director of sales, Telephonyware, a firm that packages and sells opensource software and supporting hardware.

In the past, “Not many people were doing these, because they required a high level of knowledge. You had to understand source code to get it working properly,” says Bodo. “Now these applications are so stable that anyone familiar with Unix can install them, and get an application up and running.’

IP PBX is the star of the new open-source movement, with the bestknown system being Asterix, but it’s not alone. Bayonne, an interactive voice-response (IVR) system, and SER (SIP Express router), a SIP proxy server by iptel.org, have been in use for several years by systems integrators.

The Asterisk IP PBX is the fuel powering several IP voice services, such as VoicePulse, a VoIP service provider that offers a hosted consumer voice service and a small-business hosted PBX service.

Asterisk has been nurtured by a young technology firm, Digium, to its current level of maturity, in which a typical integrator or VAR could set up a phone system with advanced PBX features. Digium offers free downloads of Asterisk or charges for more-stable ‘distributions’ of the software, which is constantly being refined and augmented.

Asterisk has its own signaling system, IAX (InterAsterisk eXchange), which can be used alongside standards, such as SIP. “IAX has some nice characteristics,” says Mike Crown, managing partner, The VoIP Connection, which also sells hardware and software to support opensource projects. “It solves the NAT (network-address translation) problem nicely and is efficient in signal overheard. But SIP allows you to establish a conversation and then devices go peer-to-peer and unload the server.” Both systems have strengths and are appropriate for different situations, Crown says.

Digium earns revenue by competing with some of its integrator customers, acting as an integrator itself on many projects. “Though Digium does not have VARs, there are dozens, if not hundreds, of companies out there that have realized you can make a good living installing this and compete with Digium on service,” says Bodo.

Asterisk is not alone in the open-source IP PBXs. Pingtel Corp., the earliest vendor of IP phones, also developed SIPxchange, a software IP PBX system that it now promotes as an open-source product. The company offers an enterprise distribution of SIPxchange using a yearly subscription model that includes support and documentation of all the changes and additions to the product.

The real advantage of open-source software is its affinity with what integrators do on their other projects. “The beauty of it, and what is helping it break out big, is that is based on open standards and, in the case of Asterisk, on the whole open-source philosophy,” says Crown. An integrator is not “beholden to proprietary products anymore. They can engineer and architect a system the way they are used to engineering the network or any other data-processing type of application.”

Using open-source means the VAR can tailor each deployment to the customer or circumstances. “Instead of going to the Nortel people … where you are basically buying everything out of the Nortel catalog,” says Crown, “you can pick the best solution from each vendor and be sure that it will all work together.”

To ease the path for VARs, The VoIP Connection offers its own Asterisk appliance that has no moving parts: all memory is solid state (no hard drive) and heat is dissipated with a heat sink. The $1,500 box includes a fully featured distribution of Asterisk sufficient for businesses or service providers. VoIP Connection augments its systems with a selection of IP phones, Asterisk software and power-over-Ethernet networking (so phones stay up even if power goes out).

Another firm, Blue Lava, has packaged an implementation of Asterisk on a PC with an IP phone and user interface for just under $1,000.

The availability of stable software and bargain-priced hardware is drawing many into open-source deployments. “We are at a confluence of programmers, system administrators and telecom VARs all converging on their Linux administration skill set,” says Bodo, “because you can make an awful lot of money doing it.” Further, he says, “It is one of many applications driving familiarity with Linux and the number of VARs who will support Linux.”

Bodo has been surprised that relatively few data VARs have approached him about doing Asterisk installations. “I’m finding that traditional telecom VARs are really good business people and have been working at this hard for a long time and have lot of customers,” he says. Traditional Linux VARs “don’t want to touch a phone or even hear about Asterisk, as far as I can tell. I’ve told them about it but haven’t found too many white-box centers that are even interested,” he adds.