Open source packs free IP telephony

Open source IP telephony software packages are helping users move away from the traditional world of proprietary office phone systems, PBXs with closed operating systems and expensive specialty components.

Users also are taking advantage of Linux for running IP voice. Observers say open source telephony software packages - many as good as commercial products - are further opening the world of packetized voice.

The open source Linux platform is a growing part of the computer telephony infrastructure at Sitel Worldwide, an Omaha, Neb., a company that runs call center operations for customers such as Cox Communications, Verizon and Mitsubishi Motors. Sitel has deployed Linux servers running the company's call center application and database to more than 20 of its call center sites worldwide.

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Open source IP telephony software packages are helping users move away from the traditional world of proprietary office phone systems, PBXs with closed operating systems and expensive specialty components.

Users also are taking advantage of Linux for running IP voice. Observers say open source telephony software packages - many as good as commercial products - are further opening the world of packetized voice.

The open source Linux platform is a growing part of the computer telephony infrastructure at Sitel Worldwide, an Omaha, Neb., a company that runs call center operations for customers such as Cox Communications, Verizon and Mitsubishi Motors. Sitel has deployed Linux servers running the company's call center application and database to more than 20 of its call center sites worldwide.

The Dell PowerEdge 2650 servers, which run a Red Hat Linux and an Oracle Enterprise Server database, interact with Nortel circuit-switched PBX systems at the sites, providing call center applications such as "screen-pops" or windows with customer information brought up through caller ID technology.

Scott Clark, director of systems at Sitel, says he is pleased with the stability of Linux in the company's call centers, especially because many sites are in far-flung locations with no onsite technical support.

Unlike Web, file or print servers - the traditional role of Linux in many companies - Sitel's Linux boxes are running an application that operates in real-time with the company's call-routing infrastructure, which requires zero downtime.

"The [Linux] servers are rock-solid, and you don't have to mess with them," once they're deployed, he says.

Sitel uses several IBM RS/6000 servers running AIX in its central data center, but Clark found that distributing RS/6000 servers to all its call centers would be cost-prohibitive. With Linux he says he saved about $9,000 per server as opposed to using IBM/AIX boxes.

Sitel also uses Red Hat Linux servers to run its call-recording application, a package called TantaComm Dart, which records customer service calls for Sitel's credit card and banking customers, and stores the data for seven years - a requirement by law for those industries.

For users comfortable with open source software and have a do-it-yourself mindset, there are many options for deploying Linux and other types of free software in a voice-over-IP (VoIP) or computer telephony environment.

Two open source software packages that provide Session Initiation Protocol (SIP) and H.323 protocol gateway support are available for free from Vovida and Columbia University's computer science department.

Vovida, a company that Cisco acquired in 2000, offers a Linux-based telephony server that can provide protocol translation for H.323, Media Gateway Control Protocol and SIP, and a SIP proxy and conferencing server.

A free SIP-H.323 gateway is available from Columbia's Web site. The software translates traffic among devices using these two protocols, allowing SIP- and H.323-based phones switches to live on the same network.