Allworx's trio of product lines include two VoIP telephone handsets, three combination telephony and network servers, plus five software packages that are separately licensed for unlimited use. The PBX contains many standard features, including unified messaging and site-to-site access; the five separate applications add specific advanced functions, such as call queuing or conferencing, allowing you to purchase only the capabilities you need. Each server eases administration with automated backup.

Allworx loaned me its high-capacity 24x server (supporting 100 employees per site with extender hardware) and top-of-the-line 9212 phones. The slim server connected to my LAN hub and external Internet, and provided five FXS ports for analog phone lines.

Allworx recommends configuration by a reseller, and I won't argue. Although its Web-based administration console centralizes setup of all server and telephony functions, and takes you through a checklist for a typical configuration -- network configuration, enabling VPN, and final testing -- a lot of settings aren't especially clear. It took me a few days to get the system totally running. Still, I appreciated the network installation tools (new in the latest Version 6.8 system software). One helped me avoid IP address conflicts. Another, Trace Route, identified lags in my network so that I could improve QoS.

Experienced system administrators can use this software to quickly perform other tasks, such as adding extensions and managing the nine auto attendants. Again, you might want to leave this to your reseller, which can remotely manage your setup.

My Allworx Manager, an internal Web site, lets users configure their personal settings, including presence, conferences, call routes, and phone features. Even with the depth of features, such as seven presence settings for each user, the software makes these changes fairly goof-proof.

For example, determining how calls are routed is all done through drop-down list selections that you make in logical sequence. This solution, like PBXtra's, has follow-me calling. Put simply, based on your presence setting, you can route your call to multiple external phone numbers, and then back to Allworx voice mail.

When I put Allworx through heavy real-world testing, its flexibility was very apparent. The 9212 VoIP phone, with 12 programmable function keys and an informative LCD, should be welcome by employees who place or receive a lot of calls; this made tasks like call transfers a breeze. Additionally, the handset's voice quality was high.

I wasn't surprised that the system's basic telephony features -- listening to voice mail, forwarding messages, and changing presence -- worked without a hitch from the phone; Allworx has been in this business for 10 years. Yet it was some of the new features that made Allworx a bit more polished compared to other solutions.

For instance, now you can make outbound calls through the system no matter where you are -- and the person you're calling sees your business caller ID. I also liked voice mail text messages and escalation. Here you have the option of getting an SMS text message from the system each time a voice mail is received. Moreover, if the message isn't retrieved within a set time, it could be sent to your backup coworker -- valuable for on-call medical personnel or support staff serving customers paying for guaranteed response times.