Small and midsize businesses face many obstacles when trying to compete with larger enterprises. One classic handicap of the smaller business is the second-class phone system, the shortcomings of which are both glaringly apparent to callers outside the organization and keenly felt by the employees inside, who know that sounding professional when clients and prospects call is a crucial part of building relationships and sales.

If anything, the movers and multitaskers who run a smaller company need even smarter telephony features than the big guys. But of course, many SMBs don't have the resources to purchase and manage an elaborate PBX phone system.

The five IP PBX appliances reviewed here are reasonably priced and easy to administer and use. Some can be installed without the need for expert help. And their telephony features -- typically configured and accessed from a browser or lightweight desktop application -- are all remarkably sophisticated.

Like other networking systems, these solutions plug into your LAN and Internet pipe (if you have VoIP service) or to analog PSTN lines. Whether your external phone service is analog or digital, voice is then passed over your existing data network to digital handsets. This alone can save you money, because you avoid additional cabling costs, not to mention rewiring when employees join the firm or move.

But there are even bigger advantages to these systems. For one, they have the potential to reduce your computing infrastructure outlay to one-third of what you might expect to pay if you purchased components piecemeal and assembled the system yourself. That's because some of the products tested replace up to six devices, including routers, e-mail and file servers, firewalls, and NAS.

Second, their primary telephone features help your office run more efficiently. All the solutions (though to a lesser or greater degree) let you define what happens to incoming calls, such as routing them to an attendant or to voicemail during specified hours. You can establish interactive voice prompts that direct callers to different departments. Users have the option to redirect calls to alternate numbers, perhaps a cell phone, when they're off-site. Plus, the systems can alert users to voice messages through e-mail.

Pluses and minuses

Often you get (or can purchase as options) advanced features, such as call queuing, which is valuable for support departments. Just be cautious of feature overkill, which might defeat two of the primary reasons to purchase: ease of management and ease of use. For instance, do you really need a phone system that has built-in Web and file servers? Such all-in-one approaches may be a godsend to some offices, while introducing needless complexity to others.

Most of the units support a good range of VoIP handsets -- usually from name vendors that include Linksys and Polycom.

Scalability is a significant differentiator, with these systems supporting anywhere from eight users to more than 300. Remember, though, as you add more users you may hit the wall of network bandwidth, as increasing volumes of digital voice -- as compressed as it is -- begin to contend with printing, file server, and other network traffic. To get around this problem, vendors in this roundup often include QoS and bandwidth management utilities.

My final important discovery -- something that vendors don't like to discuss -- is that system costs are potentially just part of your outlay. Hidden expenses can be US$5,000 to $10,000 for a reseller to install and customize your IP PBX. Even with that extra cost, these solutions all deliver on their promise of providing communications for SMBs on par with far more complex and pricey alternatives.

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?