3 min read

Vendor lauds open source PBXs

However, analyst cautions support may be lacking

Private branch exchanges (PBXs) with open source telephony software cost less than voice products from major manufacturers while allowing integrators to customize telecom installations, according to vendors who sell the technology.

Equipment manufacturers, resellers and end-users are buying open source software because they hear it will save them money, said Kevin Fleming, senior software engineer for Digium Inc. of Huntsville, Ala., which makes Asterisk, a Linux-based open source PBX operating system.

“To some degree, it’s completely irrelevant to the end user that it’s based on an open source product, other than the fact that they get a much more powerful system at a lower cost,” Fleming said. “They don’t necessarily care that it’s open source, they just go to the vendor and say, ‘This is what I want to do,’ and the vendor says, ‘Okay, we can do that for $4,000,’ and they go, ‘Wow. Okay. When can I have it?'”

He added that systems integrators and resellers can use it to customize telephony installations for their customers.

“We hear a lot from resellers who have learned that they can solve the customer’s problems in more creative ways when they have a tool like this available that lets them basically modify anything they want, even to the point of being able to integrate their systems with some carrier,” he said.

One vendor using Asterisk for customized installations is Montreal-based Aheeva, which also uses the software for a contact centre software product.

Aheeva’s IT director, Claude Klimos, said his company made some changes to Asterisk for a customer who wanted to be able to transfer calls without losing the call.

“We had to adapt to make it an assisted transfer, not a blind transfer.” meaning the person doing the transfer would remain on the call until they hung up.

Another feature Aheeva added was the ability for companies doing telemarketing campaigns to detect whether the call was answered by a live person or by an answering machine.

“Some features that will give u a little advantage over competitors, we hold on to for a certain time, and then after maybe a year or two we submit them to the community,” he said, adding Aheeva also fixed some bugs and submitted them to the developer community.

Asterisk includes telephony services such as voicemail, conferencing, three-way calling and caller ID. It includes a central switching core, four application programming interfaces for telephony applications, hardware interfaces, file format handling and codecs. Version 1.2, which was released last November, supports the Distributed Universal Number Discovery protocol and supports more session-initiation protocol (SIP) features than previous versions.

SIP, which originated as a signaling protocol, allows telephony and conferencing devices from different vendors to work together, and support for open standards is one reason users choose open sources telephony, said Joshua Stephens, chief executive officer of Switchvox Inc., a SanDiego-based maker of Internet Protocol telephony equipment based on Asterisk.

“Since Asterisk is built on top of SIP, and other open standards, it works with other people’s products, and you don’t have to worry about, ‘Did they do it this way or did they do it that way?'” Stephens said. “It removes a lot of the barriers that would otherwise be there with proprietary software.”

But just because a PBX supports SIP does not mean it will work with advanced features from other manufacturers, said Zeus Kerravala, vice-president for enterprise infrastructure at the Boston-based Yankee Group.

“More and more companies are embedding instant messaging features, Web conferencing, audio conferencing, different collaborative features,” Kerravala said. “It’s not just the ability to make the call.”

He added that users who buy open source to save money may miss out on these advanced features, and may end up paying more to support the products.

“In general, you don’t get what you don’t pay for,” he said. “For the buyer, it may look attractive from an initial acquisition standpoint, but take a look a a five to seven to 10-year total cost of ownership, when you include hiring people, retaining people, training them.”

Kerravala said products from major manufacturers may be more expensive, but there are more technicians trained on these products.

“Even if you need a consultant to come and help you, you can pick up the Yellow Pages and find a bunch of Avaya-certified, Nortel-certified and Cisco-certified people, but to find anybody who knows Asterisk – that can be a lot more challenging.”