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.

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.

The AIP optionally can be had with conference calling, voice recording, and Internet linking (which means you can connect to another AIP at a remote location for free using the Internet). One limitation: Each voice mail box can hold only 10 messages of 90 seconds each. But you can increase the size by installing a larger CFC (Compact Flash Card). You also can use a CFC reader on a PC to make backing up your voice mail fast and easy.

Not as Open and Shut

The ease with which I implemented the AIP-416 left me unprepared for the difficulty in getting OpenVoice running. bConvergent told me that the OpenVoice software would work with Windows 2003, but I was never able to accomplish that. Likewise, I was never able to run it on Windows 2000 Server. In both attempts, I used one of InfoWorld’s HP ProLiant DL360 servers. Only with the help of bConvergent engineers at my testing facility in Washington D.C. was I able to get the PBX successfully installed on a Dell desktop computer running Windows XP. (No engineers were on hand during my initial testing in Hawaii, thus they were not able to determine why I was unable to install it previously). Clearly, this installation is not intended to be a do-it-yourself project, but then again, bConvergent doesn’t present it as such.

OpenVoice can support any number of users, limited only by the capacity of the computer on which it’s installed. The minimal Dell minitower I used worked just fine for my testing. However, bConvergent will normally provide a platform for enterprise installations that’s more robust.

Once it’s installed, you can access the PBX through a Web-based management utility that’s plain and very straightforward. Through this interface, you can control everything from user names and extension numbers to the features available to each telephone and user.

The OpenVoice PBX worked well once it was up and running. Calls were clear and suffered little latency, and the automated attendant made inward call routing a snap. In general, the whole solution will fit well into an enterprise network. All of the features you’d expect from a modern PBX are on OpenVoice, including easy-to-use voice mail, holding, transfers, caller ID, and conference calling.

One missing feature is access to the POTS network or to analog PBXs. bConvergent provided that capability through an external gateway from Quintum called the Tenor Multipath Switch. This $1,300 device sends externally bound calls out through the analog voice network. In addition, it will support a few analog phones directly attached to the gateway. The device I tested as part of the bConvergent solution supports up to four PSTN connections and four analog connections. Larger units are available.

Although the company claims the solution will work with most hardware and platforms, I found that the PBX would only work using phones from Uniden and Polycom. bConvergent says that some of its distributors use Swissvoice and other IP phones, but I was not able to use those successfully.

Once implemented, I found both the AIP-416 and the OpenVoice PBXs to be easy to use and appropriate for business use. For smaller offices, the AIP-416 wins hands down. It’s inexpensive, easy to use and manage, and it works very well with little hassle. OpenVoice’s PBX is a more compelling choice for larger business that might be able to handle the 32-station limit. You should be able to expand the PBX as your company grows, provided you get the user licenses and make sure your platform is up to the task. Like the AIP PBX, OpenVoice inexpensive; however, the implementation will cost more (the exact amount will depend on who does it and how much they charge you).

Also, bear in mind that OpenVoice is based on Windows, which means that you will have a mission-critical function based on an OS that requires frequent, active maintenance to maintain security. This might give some companies pause.