Making The VoIP Call

Doors Open To Open Source
Solution providers that want to integrate their own PC-based systems can turn to open-source VoIP software such as Pingtel SIPxchange and Asterisk. Asterisk solutions offer high-end features at a lower cost than offerings from rival vendors, said Chad Agate, co-founder and CEO of NeoPhonetics, a solution provider in Tinley Park, Ill., that integrates a VoIP solution based on the Asterisk platform.

Asterisk may be the most popular option. Digium, the Huntsville, Ala.-based creator and primary developer of Asterisk, claims the software has an installed base of more than a half-million users. More than 500 people have contributed to the current version, and there are plenty of online resources and books that cover it in detail. It is most commonly deployed on Linux but can be installed on Microsoft Windows.

"Open source is advanced enough to be accepted in Fortune 500 companies, and you don't have to be a Linux guru to get it going," said Jim Webster, Digium director of software technologies.

Most any standard PC makes a fine Asterisk platform for just a couple of calls. For a system that will support 100 users, a typical server running at 2GHz or 3GHz with 1 Gbyte of RAM is sufficient. Other pieces may be required, such as interface cards for analog phones and T1 lines and transcoding cards to offload and increase the number of calls the IP-PBX will support.

Digium sells all the hardware a solution provider will need to build a fully functional PBX. Digium also sells the Asterisk Business Version, which costs $995 and includes warranty, support, maintenance upgrades, help with bug resolution and access to custom development support. The package supports 40 simultaneous calls, which should be enough for 160 users. Upgrade licenses for an additional 40 simultaneous calls cost $695. A single Asterisk server can support a maximum of 240 simultaneous calls, and software is available that allows multiple Asterisk servers to be clustered together.

Digium also offers a developer kit consisting of a small appliance with an embedded processor and flash-based memory. There are no hard drives or fans, so the appliance is completely quiet. It supports up to eight analog lines or it can be set up as IP only. The kit costs $2,195 to $3,995 depending on the level of training a partner requires. The appliance is intended to encourage VARs to build applications for Asterisk.

But the company is also planning to launch an appliance for end users that should help ease deployments. "There is a whole group of resellers who love to add value through their Linux expertise and integration expertise and who are willing to do that level of integration. That market is growing," said Steve Harvey, vice president of worldwide sales at Digium. "But most customers don't want to mess around to get their hands that dirty to make a phone system work."

Some solution providers, like CT Networks, still have their doubts about whether open-source telephony solutions are stout enough for enterprise deployments. "The problem is there's so much legacy programming and the PBX gets so complicated with T1 circuitry and functionality that goes to five-nines reliability," Goldstein said. "Open-source has a long way to come before it's a candidate for enterprise environments."

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