News attracts open VoIP systems

A growing number of open-source developers of voice over IP (VoIP) applications are finding their way to the Web site. Created two years ago by Vovida Networks, and now sponsored by Cisco Systems, which acquired Vovida in November 2000, the community site has been presented as a forum for open sourcers working on VoIP.

"The goal of is to promote the development and adoption of communications products, features and services on IP-centric networks, says Alan Knitowski, co-founder of Vovida and a marketing executive at Cisco.

Knitowski's company developed the Vovida Open Communication Application Library (VOCAL), Linux- and Solaris-based software said to enable a core network to support a VoIP system. VOCAL is available through a BSD-style, open source license at Cisco says that there have been more than 5,200 downloads of VOCAL to businesses, educational institutions, and individual developers. also hosts a variety of open source applications, protocol stacks, and VoIP-related projects. Cisco provides funding and technical expertise, as well as providing links to open source information sites. attracts contributions from a range of open-source datacom and telecom system developers. VoiceAge of Montreal, for example, recently said it will make a developers' version of its G.729 (A) voice compression software available for free at the site. A developer's version can be used for product development and non-commercial purposes. Observers say VoiceAge-type systems widen appeal by generating discussions on the open mailing list, and attracting a new audience to the site.

At the same time, VoiceAge aims to hasten adoption of its technology by making it available on the site. "Contributing part of our technological portfolio to became the only logical choice when considering our dissemination objectives for a targeted, globally centric VoIP development community," says Laurent Amar, VoiceAge VP of strategic planning and business alliances.

Dialpad Communications, Inc., has also been working with software to deliver the new Microsoft XP PC-to-Phone service on Genuity's Cisco Powered Network. Dialpad's application, a SIP-H.323 translation system, includes open-source code provided by the VOCAL system.

Cathay Networks, Inc., has built a large-scale IP to PSTN call-routing system on top of VOCAL components, and is developing carrier-class VoIP solutions for residential and business users. Cathay has made numerous contributions to, according to Cisco, including a high capacity load generator.

Other contributors to include:

  • Jasomi Networks, Inc., which has incorporated portions of VOCAL into its inter-carrier peering and NAT traversal products.
  • First Virtual Communications, Corp. (formerly CUseeMe), which contributed the Win32 port for the SIP stack.
  • Tangerine, Inc., which provided development partnership for software design and support packages for the Vovida SIP, MGCP and RTP protocol stacks.
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About the Author

John K. Waters is a freelance writer based in Silicon Valley. He can be reached at [email protected].