VoIP is one of the areas in which open source is having a significant impact. Companies including Digium, Fonality and Pingtel (owned by Bluesocket) have commercial open-source offerings for VoIP that meet the needs of small and midsize businesses, as well as larger enterprises.
"We're also seeing regional VoIP offerings that are providing hosted VoIP services based on open-source technology," Zachary says. "A number of VoIP open-source projects are emerging from the community, and many are focused around the consumer market."
The open-source VoIP projects in operation today include Asterisk, CallWeaver and SipXecs.
In 2004, Hersha Hospitality, a real estate investment group that invests in hotels in business districts and suburban office markets, replaced an aging time-division multiplexing (TDM) phone system with an Asterisk-based VoIP system from Digium.
The old system provided limited calling capabilities and was running out of capacity, so it could not accommodate Hersha's growing business. The company looked into several options, including other TDM systems and hybrid systems that combined VoIP and TDM.
Harrisburg, Pa.-based Hersha opted for VoIP because of the potential cost savings and additional calling functions, such as in-house teleconferencing, that the technology would provide. To keep costs of the new phone system down even more, Hersha chose to build the VoIP system internally using open-source software rather than buying a commercial VoIP system.
"When we made the move to VoIP, two of our requirements were flexibility and low barrier to entry," says Jason Shane, Hersha's IT director. "Asterisk measures very strong in both areas."
Hersha's IT department built the system in phases using Asterisk. The company later tried to expand its VoIP system to connect employees in the Harrisburg office with those in a key Philadelphia facility via direct dialing and conferencing.
But expanding the system was more of a challenge than Hersha expected, and the company brought in telephony consulting firm EUS Networks to help rebuild the VoIP systems in Harrisburg and Philadelphia so they would be more scalable.
EUS completed the makeover in 2007, and Hersha now uses the Asterisk-based system as its voice telecom backbone. The VoIP servers handle direct-dial calling between the sites and remote offices, voice mail, conferencing and other functions. Shane estimates that Hersha spent about $375,000 less for the Asterisk systems than it would have for a commercial VoIP product.
With the VoIP system, Hersha built remote offices quickly and enabled staff and mobile users to connect with voice mail, fax to e-mail, and contact colleagues and partners with instant messaging. Hersha plans to launch an enterprisewide IM system--using an open-source platform called Openfire--that ties in with its VoIP phone and e-mail systems.
But it wasn't a cake walk. One of the challenges that Hersha faced was overcoming the misconception that open source is free: The software was free, but implementing and supporting it added extra costs. "But once the company saw the value of the system and we brought in appropriate support," Shane says, "we've never looked back."