The VoIP-PBX connection - Technology Information

Communications News, May, 2001 by Al Brisard

The right transport mechanism arrives on the scene.

Through the years, there have been attempts to merge voice and data networks, notably in the 1980s when PBX manufacturers themselves tried to introduce their version of integrated voice and data PBXs. Not until the Internet revolution and the widespread development of IP data networks did the industry at large finally have the right transport mechanism to support voice and data convergence.

Several major drivers for the convergence of voice and data networks include:

* Flexibility. Using IP as a transport mechanism offers companies the flexibility to deliver voice traffic to virtually any location over any type of media.

* Lower cost of ownership. Companies recognize that consolidating their networks can save on communications costs--on everything from reduced long-distance charges between offices to reduced administrative overhead.

* Corporate decentralization. Companies continue to decentralize operations without increasing overhead, and draw from a larger geographically dispersed labor pool. In order to do this successfully, companies must find ways to deliver a uniform level of voice and data services to remote employees, in order to overcome the communications barriers imposed by time and distance.

* Next-generation business applications. Competitive pressures are forcing companies to deploy these applications in order to deliver better services to customers, partners and employees. Implementing these applications will depend, in large measure, on the ability to converge voice, data and even video.

THE LEGACY DILEMMA

The great tension in convergence is between the benefits of voice over IP (VoIP) and the economic feasibility of displacing existing telephone systems, which represent a significant investment for corporations. They offer a rich feature set for voice communications, excellent voice quality and a proven track record for reliability. In short, existing telephone systems are superb for what they were designed to do.

What they were not designed to do presents the problem--traditional PBXs were designed for voice-only communications and location-centric operation; therefore, they are poor at networking and do not integrate easily with other traffic types, such as data and video.

Deploying traditional voice platforms in remote locations often results in a hodgepodge of incompatible equipment from different vendors. These systems may or may not network with each other, and will probably have dissimilar feature sets, dialing plans and applications. In addition, companies relying on circuit-switched networks cannot take advantage of new emerging services propelled by low-cost, high-bandwidth access technologies like digital subscriber line and cable, which can provide both voice and data services to smaller offices and home-based employees.

PBXs are also proprietary platforms that are not easy to integrate with other systems and applications. Telecommunications managers often have to rely on their PBX vendor to add or integrate a new application. This creates difficulty in placing the company on a technology road map for converged business applications.

VoIP excels at networking, which makes it ideal for serving remote locations. Designed for supporting multimedia communications, it makes the perfect vehicle for supporting converged applications. IP-PBXs, however, do not yet have all the capabilities of traditional voice systems. These solutions require a forklift replacement of the existing telephone systems, which most companies perceive as too revolutionary.

A SENSIBLE APPROACH

While some vendors and industry analysts preach the domination of packetized voice over circuit-based voice, the reality is that the marriage of the two, at least for the foreseeable future, is a more sensible approach for companies to take. VoIP is still maturing, and telecommunications managers are not ready to entrust their whole enterprise to the technology. At the same time, VoIP is as inevitable as the Internet--its benefits are too compelling. Companies may ignore the technology at their own peril, while bolder competitors exploit the technology sooner, and operate more efficiently or deliver new services faster.

Because of these factors, the discussion should not be about how to choose between these two ways of delivering voice but how to bring them together. In fact, IP does not have to be viewed as a replacement for traditional voice systems, but as the transport vehicle for extending all of the PBX features and functionality to remote locations. At the same time, IP sets the stage for designing and deploying convergence-based business applications.

Rather than talk about VoIP only in terms of IP-based PBXs, which suggests radically different voice communications paradigms, companies should consider the concept of distributed voice services (DVS) over IP for the extended enterprise. With DVS, companies can leverage the power and flexibility of IP to extend traditional voice systems beyond the boundaries of the corporate headquarters. This can be a practical and realistic approach to convergence for established corporations, and is one that many of the major PBX manufacturers themselves are now embracing.