The system's telecommuting technology is notable; employees can travel outside of the office with an IP phone (or softphone) and keep their extension number -- so there's no need to create an "out of office" voice message.

Right from the box, PBXtra has very good Outlook integration. When your phone rings, the caller ID is analyzed against your Outlook contacts. Additionally, if you use the Firefox browser, the new FONcall plug-in turns any phone number on a Web page into a click-to-call link.

Even so, you may want to invest in the Heads Up Display (HUD) option, which costs US$995 for unlimited licenses. HUD brings a lot of efficiencies to SMBs. For instance, this highly visual application lets you dial a person from your Outlook inbox. But HUD really stands out by showing your entire organization, who is on the phone, and to whom they are talking. You can drag and drop new or existing calls to someone's extension, voice mail, or a general parking area.

Yet another advantage of HUD is presence awareness, but this only works with the Professional and Call Center configurations. If you walk away from your desk, for example, the system knows your status and could automatically ring your cell phone.

Other features missing from the Standard system include conference bridges and various groups. No PBXtra 4.0 configuration has collaboration options, such as a file server. On the other hand, PBXtra's reporting across all configurations is very strong. For example, you could see all incoming calls from a particular area code, which could be valuable for marketing efforts.

PBXtra 4.0 is an extremely capable phone system, even in the basic configuration. With features ranging from auto attendant and Outlook integration to telecommuter and branch office support, there's little more to desire. If you need group or call center features, you can step up to two still-affordable options. And Fonality takes care of monitoring, management, and backups. Be aware, however, there are extra one-time costs to provision each phone, and be sure to budget for yearly maintenance fees.