Some weeks ago the Gearhead Underground Bunker started to fill up with some really cool VoIP stuff, including 3CX's free software-only VoIP PBX and a couple of D-Link VoIP DVG-2001S Terminal Adapters that convert regular telephones into Session Initiation Protocol (SIP) phones. This has resulted in more than a few hours of play, er, testing and analysis over the last few days.

The 3CX Phone System is a full-featured PBX that runs on Windows 2000, 2003 or XP, is free and supports unlimited extensions but is limited to eight outside lines (PSTN or VoIP providers).

Three other versions of the 3CX Phone System (www_.nw_docfinder.com/8228) are planned for release: a Small Business Edition ($350, 25 extensions, 16 lines), a Professional Edition ($850, unlimited extensions, 32 lines) and an Enterprise Edition (price to be determined with unlimited extensions and unlimited lines). The Small Business Edition is due out very soon, with the other two versions due in the next few months.

The 3CX Phone System supports hardware and software SIP phones, including 3CX's own free SIP softphone as well as SIP-based VoIP gateways and SIP-based VoIP providers.

All versions of the 3CX system include personal call history, call logging and reporting, blind and attended call transfer, call forward on busy and on no answer, hunt groups, call routing (DID), caller id, conference calling, autoattendant and digital receptionist, voice mail, and music on hold. Conference calling and digital receptionist require SIP phone support.

The 3CX system has an embedded Web server (Apache), and is configured and managed through a Web interface. The interface includes real-time reporting. For example, the server log updates automatically every few seconds.

To add a physical line you'll need to add a SIP gateway. Adding a line from a VoIP service provider requires configuring the system and possibly your firewall.

The 3CX Phone System is excellent. It is a lot simpler to set up and manage than, say, Asterisk, and is a useful test bed and learning tool as well as a great small-business solution.

Besides using the 3CX SIP Phone with the 3CX system, we used regular phones by connecting them via D-Link VoIP DVG-2001S terminal adapters.

The DVG-2001S (priced at about $60) is a cool device that works great once you are past the setup, which is a little buggy. The process isn't helped by the fact that the manual is fairly bad. Doesn't anyone at D-Link proof their manuals? Phrases such as "your D-Link VoIP Adapter splits converts your analog signal to digital" are inexcusable.