Some 700 users and enthusiasts of the Asterisk IP telephony system gathered in Dallas this week for the third-annual AstriCon conference, focusing on the open-source IP PBX and messaging software package.

A diverse crowd of corporate telecom professionals, open-source developers, vendors and entrepreneurs attending AstriCon gave the signal that IP telephony, and open-source VoIP are evolving from being a niche market or open-source programming hobby into the mainstream of IT, at least according to one attendee at the show.

"I attended the first AstriCon three years ago, and it was really a narrowly-focused [open-source] developers' conference," says AstriCon attendee Arnold Solomon, an IT architect at the Southern Company, a conglomerate that manages energy utilities in five southern states. He estimated that about a third of the attendees at this year's conference were enterprise or small business IT professionals looking to find out more about open-source telephony.

The conference, which was held at the Dallas Westin Park Central, attracted around 35 exhibitors, including IP phone maker Polycom and Digium, the corporate face of the Asterisk, which sells support and services around the open-source platform.

Solomon gave a talk at AstriCon on some of his company's production implementations and test applications using Asterisk. These include a system that integrates the company's older Siemens PBX system with its BlackBerry servers, allowing the phone system to send e-mail alerts to users about important voicemail messages left for them on the systems. Solomon also discussed a possible scenario for moving large blocks of direct inward dial (DID) numbers to a different location using SIP-based servers and Asterisk.

"We demonstrated a way you can move a gigantic block of numbers in seconds, while keeping those calls on the internal voice network," Solomon said. The company did this using SIP number diversion, where calls made to an incoming PBX number can be rerouted via an Asterisk SIP server. Solomon says this technology could be used in disasters, such as Hurricane Katrina, in which large numbers of workers could be relocated to another facility, but keep their telephone numbers while working out of a temporary space.