In deciding which of these solutions might satisfy your needs, start by asking a few questions. Are you a single, small office or a fast-growing SMB with multiple sites? Do you have someone skilled to manage the system? Do you need only a PBX or would Web and file servers be valuable?

And the winners are…
Small offices with five to 25 employees should look closely at Microsoft Response Point and Sutus Business Central and also consider Fonality's PBXtra. If simplicity is more important than features, Response Point is my choice. But if telephony features are the main attraction, then I give the nod to PBXtra. If an all-in-one system is appealing, then you can't go wrong with Sutus.

Larger organizations should seriously consider Allworx, Critical Links' EdgeBox, and PBXtra. Because these solutions all have extensive features, the selection isn't as clear cut. My recommendation, unless you need surplus features such as a router or firewall or Web server, is to go with PBXtra. Moreover, when you consider the cost of software editions and especially phones, PBXtra scales more economically than Allworx and EdgeBox.

Below are the test scores (on a 10-point scale) and brief summaries of the five solutions. For more detail, follow the links to the complete evaluations.

Allworx 24x v.6.8
Score: Very Good  8.6
Bottom Line: A true all-in-one system, each Allworx appliance combines full PBX and VoIP duties with networking functions including automated backup, e-mail and Web server, security, and LAN management. Rich communications features include unified messaging and presence awareness, along with options such as call queuing, a conference center, and group calendaring. Another important differentiator is site-to-site access, with 100 sites supported. See complete review.

Critical Links EdgeBox Office v.4.5.2
Score: Good  7.9
Bottom Line: This all-one-one appliance integrates Asterisk telephony, networking, e-mail, file sharing, and Web server into a single enterprise-grade solution. However, the many moving parts and interfaces add complexity to configuration and use. Phone services include interactive voice response and conferences as well as queues and other features for call centers. QoS management lets administrators set VoIP and Web caching policies. See complete review.

Fonality PBXtra 4.0
Score: Excellent  8.8
Bottom Line: PBXtra is a scalable phone system with a user-friendly interface, making it easy to install, use, and maintain. A "hybrid hosted" architecture lets Fonality remotely manage the system. The basic configuration is value-laden, with strong Outlook integration, conference bridges, and CRM hooks; plus it supports analog and VoIP phones. The Professional edition adds multiple auto-attendants and conferencing, while Call Center tacks on unlimited call queues and agent capabilities. See complete review.

Microsoft Response Point 1.0
Score: Very Good  8.3
Bottom Line: Response Point combines software from Microsoft and hardware from IP telephony vendors. Reliable voice recognition -- without any training -- is unique among the products tested, and helps make the system remarkably easy to use. Setup and admin are a snap, and it's easy to add new users and phones -- up to 50 without additional licensing fees. Telephony features are basic. If basic meets your needs, this system is a perfect fit for the small, Windows-centric office. See complete review.

Sutus Business Central SB-200
Score: Very Good  8.4
Bottom Line: Sutus' unified communication solution combines telephony, e-mail and file servers, and even wired and wireless networking in a single box. This reduces hardware costs for offices of up to 25 users, while easing administration. The system integrates VoIP and PSTN lines, via an included gateway, while phone services convert voice mail to e-mail. Sutus lacks the advanced telephony features and expandability of some competitors, but its wizard-driven setup, reliability features, and collaboration spaces should be a hit with smaller offices. See complete review.