Are you an IT manager at a small business who is looking to leverage VOIP benefits but doesn't want to go through a wholesale hardware replacement?

Do you also have geographically dispersed offices? And are you looking to put a more professional front on your company's public telephone presence? Then you may want to look into hosted virtual PBX services.

With prices starting as low as $10 per month per user, companies such as VirtualPBX and GotVMail have telephony services that provide both front- and back-end services for a company's existing telephone infrastructure.

These hosted services provide a unified incoming number for all employees, ACD (Automated Call Distribution) services to correctly route incoming calls to the proper contact person, voice mail (as well as e-mail access to voice messages), and conference calling and call forwarding among extensions, among other services.

Potential customers should be aware that many of these services are often priced on an a la carte basis—take the low initial cost estimates with a grain of salt and ensure that all desired features are present and accounted for in the quoted price.

While these service providers likely use voice-over-IP technology somewhere in their data centers, a hosted PBX is not a VOIP service.

To read more about Siemens' SOA IP PBX for medium-size enterprises, click here.

Companies that decide to use a hosted PBX solution therefore will not have to provide employees with new phones.

Instead, the hosted service routes calls from a central front-end number to employees' existing telephone numbers—be they numbers for the office; home; cell phone; or, in some cases, VOIP.

Users need only to log in to the hosted service's Web interface to update their presence status and indicate the number at which they can be reached.

At the initial setup, administrators decide whether the public number should be toll-free or local.

With a little advance notice, companies can import an existing front-end number to the hosted service.

Administrators set up the call flow and the routing rule set. First, administrators define the messages they want played, the IVR (Interactive Voice Response) structure, and the users and extensions that will be supported.

These services also should allow later modifications to the call flow via an administrative Web interface.

Depending on the type of service selected, administrators may also be able to interactively view centralized call reports and billing reports.

And, to maintain the professional dimension of the service, some hosting providers may also offer (for a price, naturally) professional voice talents to record all outgoing messages.

As with any hosted service, there are a number of things to look for beyond features and price: How are system backups performed, and at what frequency? Are there geographically distributed data centers for redundancy in case of a regional calamity?

Does the service provider maintain full power, network and system redundancy within its data centers? How many users from different companies are maintained on a hosted PBX, and what criteria does the service provider use to determine the maximum number of users supported on a PBX?

The answers to these questions will provide excellent context when beginning your search.

Technical Analyst Andrew Garcia can be reached at andrew_garcia@ziffdavis.com.

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