Eighteen months after embarking on a new business model by taking its SIPxchange voice system to the open source community, Pingtel announced that Earthlink has deployed its new open-sourced, SIP-based user agent platform to support the Internet service provider’s free online calling services: Vling.

“This is a perfect example of how an open source community works and can work to the benefit of the company that’s commercializing it,” said Al Brisard vice president of marketing at Pingtel.

Pingtel’s SIPxua is a full-featured standards-based SIP user agent that enables users to deliver enterprise-grade voice-over-IP solutions as part of services offerings or embedded in applications or hardware. SIPxua includes a simple application interface, a SIP stack, media processing, and session processing technology for OEM applications.

EarthLink will use SIPxua to provide customers with softphone capabilities on their PCs as well as to support other instant communication applications like Internet Chat. Using the softphone, or soft client, Earthlink’s Vling service allows any broadband Internet customer to make unlimited calls to anyone in the world that has a SIP-compatible free online calling service.

“Plus, because it is open source, everyone else in the community gets the benefit of the work we did for Earthlink. The next service provider that comes along will have a much better starting point,” Brisard said.

Also because it is open source, the software is free. Pingtel will generate revenue from the services contract to support the code. Pingtel’s user agent is based on the sipXtapi project hosted at SIPfoundry, an industry consortium launched last year to promote the adoption of SIP-based technology. sipXtapi provides a generalized telephony interface on top of the SIP, RFC 3261, and the real-time transport protocol (RTP) and RFC 1889. It also is used in the advanced communications features (voicemail, call routing, auto attendant, conferencing and presence) found in SIPfoundry’s open source PBX as well as Pingtel’s enterprise-grade SIP PBX and softphone products.

“A lot of people were skeptical about whether putting all our [technology] out to the open source community would generate business. So this is a real validation on our model. It’s a perfect example of how an open source business model works,” Brisard said.

Pingtel has enhanced the SIPxua over last six months to make it more “consumable” by abstracting the call processing and SIP stack layers so that anyone could develop a soft client or SIP-enable applications without having to know about the SIP applications.