Critical Links' EdgeBox line includes three Asterisk-based appliances: Office (40 users), Business (100 users), and Enterprise (300 users). The 2U rack-mount servers vary in disk space (80GB to 250GB), connectivity (such as integrated Wi-Fi), and redundancy options.

Because of all these variables, EdgeBox makes the selection process easier by configuring the appropriate hardware and third-party software (called EdgePacks) for six vertical markets. For example, the Education configuration includes EdgeLMS (Learning Management System), which gives schools and corporate training departments a turnkey phone system and course management solution.

Conceptually, EdgeBox replaces a typical Microsoft Small Business Server setup. The server contains a router, network access, security, and collaboration along with storage and print services. Critical Links then layers on VoIP PBX functions, QoS utilities, and optional Wi-Fi.

EdgeBox can be used in many network configurations, but it's typically deployed as a gateway between your LAN and the Internet. A second Ethernet interface connects EdgeBox to an enterprise-wide private network.

Configuration is done the old fashioned way; you won't find any wizards or shortcuts. I used the Java Control Center to configure my local area network settings, firewall, and other basic settings. For more experienced enterprise users, EdgeBox has various authentication methods, such as using remote Active Directory, LDAP, or Radius servers. The same type of detailed settings are available for networking (for instance, changing host name and routes), though the default settings should be adequate for typical small offices.

As with other aspects of the system, configuring the Web server, Web mail, and file shares is a manual operation. However, someone with basic server administration skills should be able to figure out how to create virtual hosts and complete other required tasks. Configuring VoIP and PBX settings in EdgeBox is generally intuitive. The same is true for adding phones, which can be VoIP, analog, or softphones.

The final aspects of setup involve the IVR (interactive voice response) system; administrators may create response menus -- actions callers can take after listening to voice prompts -- for most any type of organization. Each of these "contexts" has several actions that are defined using a tabbed interface. For example, you could have the system perform a certain action on an incoming call if the caller doesn't respond within a preset time. EdgeBox software also let me apply a time frame to these rules -- such as forwarding to a certain extension only during off-business hours.

In my experience, you'll need to devote the better part of a day to get everything in EdgeBox running as you'd like.

In daily use, EdgeBox's PBX features worked just as I'd defined with the IVR editor. For instance, if someone didn't answer their phone, messages were correctly routed to voice mail. These were later easily retrieved by dialing the voice mail extension. Besides an indicator on the phone, users can also be notified of new messages by e-mail, along with the message in audio format.

Many of EdgeBox's 50-odd software packages are part of the open source Asterisk distribution, and they make up a rich and robust collection. For example, advanced PBX features include queues and agents (valuable for call centers) as well as conferences. There's also call park, call transfer, and hunt groups, where all phones ring, which is a useful feature in a support setting.

Open standards can be a good thing because of the many optional packages available. On the flip side, the many different interfaces and procedures in EdgeBox add complexity to configuring and using the system. Nevertheless, I have no concerns that EdgeBox will do a very good job. It's one of the more expandable systems. Plus, Critical Links gave EdgeBox features, such as call queues, that are sometimes optional or not available with other systems.