PBXs answer the call for enterprise VoIP

At long last, VoIP (voice over IP) is worth considering for real business use, thanks to two factors. The first is the ubiquity of Ethernet. It’s the rare business indeed that isn’t already wired with 100Mbps Ethernet infrastructure, if only because Fast Ethernet has become the de facto standard for the way networking is delivered.

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Second, vendors have improved VoIP products to the point where the voice quality is as good as the older circuit-switched technology used on the PSTN (public switched telephone network), also referred to as POTS (plain old telephone service). The pops, burbles, and latency are all gone, and it’s nearly impossible for a caller to tell the difference between a VoIP call and one using POTS.

Adding to VoIP’s attractiveness has been the development of PBXs (private branch exchanges) that are fully featured and inexpensive. PBX can now be just an application that runs on a standard platform, which means companies no longer have to pay the immense costs once associated with buying a phone system.

I looked at two solutions for small IP PBXs that are based on two different concepts: AIP Communications’ AIP-416 and bConvergent’s OpenVoice IP for Windows. The AIP-416 is a completely self-contained solution: a 1U box that plugs into your company network and a source of electricity. You can also connect it to a legacy PBX and to the PSTN if you wish. Up to 16 IP phones will work with the appliance. I used models from Swissvoice and Clarisys.

OpenVoice for Windows is a PBX application that the company claims runs on Windows 2000, Windows XP, or Windows 2003 Server, though my attempts to install it on Windows 2000 or 2003 were unsuccessful. The OpenVoice PBX is as fully featured as any competitor, has the advantage of potentially low startup costs, and can handle more users than the AIP-416 can. You must, however, install and set up the software or have it done by the company or a consultant; the process is not ideal for end-users.

Ready out of the Box

The AIP PBX was clearly ready for prime time. It arrived fully configured, ready to plug in and run. However, you can do the initial configuration on your own using the built-in, Web-based management utility. You’ll also need this utility to make changes to the PBX configuration.

The PBX, along with four Swissvoice IP10S phones, worked flawlessly from the moment I plugged everything in. The phones get their settings from the PBX, so all setup is controlled centrally once you tell the phones where to find it, which is a simple process.

I installed the AIP-416 on my simulated enterprise network created for testing 10 Gigabit Ethernet switches. Nothing the PBX could do would stress the massive bandwidth of 10GbE, and I was pleased to note that calls made it through the network during the test with no effect on latency or call quality.

The AIP-416 provides all the features you’d normally expect from a PBX, plus some others that aren’t always available elsewhere. For example, you get call holding, intercom, transfers, call waiting, and caller ID right out of the box. You can also page people, assign an operator, and set up three-way calls. In fact, if you can find a source of suitably insipid material, you can play music for a caller on hold.