October 1998

We asked several vendors for their views on the Internet telephony industry:

• Hans Schwarz, Senior VP Enterprise Networks and Development, Siemens Business Communication Systems, Inc.
• Brian Allain, Vice President, Internet Business Systems, Lucent Technologies
  Kathy Meier, General Manager, Internet Communications, Lucent Technologies
• Kerry Hawkins, Vice President Sales, Vienna Systems
• Francois de Repentigny, Product Marketing Manager, Clarent Corporation
• Marc Robins, Director of Marketing, Linkon Corporation
• Andy Voss, NUERA Communications, Inc.

Hans Schwarz, Senior VP Enterprise Networks and Development, Siemens Business Communication Systems, Inc.
To state that only one way of implementing IP telephony will triumph is overly simplistic. Siemens believes that customers will adopt the emerging technology of IP telephony at different rates, with different expectations and requirements. For some, implementation will be experimental. For others, protecting significant investments in PBX hardware will be paramount. For still others, voice quality will not be an area of compromise. Given the breadth of what customers will require of IP telephony, we believe there is a place for all three of the scenarios described.

The gateway approach is perhaps the most established method of implementing IP telephony. Siemens' Hicom Xpress gateway is based on an industry standard NT server platform. Gateways are typically designed with a great amount of redundancy. An important feature, fallback to the PSTN, is standard for gateway VoIP products. Unlike routers, gateways support call center, messaging, and directory applications. Gateways are very scalable and easily integrate into the network. The drawbacks to the PC-based gateway approach are that PCs or servers are not yet as reliable as the PBX.

Through strategic partnerships with data networking vendors, Siemens will also implement a router-based approach to IP telephony. A router-based approach is a more rudimentary entree to the world of IP telephony. Router-based solutions use proprietary operating systems. They also require a network manager who is trained and dedicated to supporting the router. Fallback to the PSTN is generally not an option. Also, routers do not support as broad a range of development tools or applications as the server-based gateway approach, which means that migration can be difficult. Routers were never designed to support real-time interactive voice or video applications.

The PBX -- long known for exceptional reliability and feature-richness -- brings some unique qualities to IP. IP telephony trunking embedded in the PBX hardware allows customers to protect their significant investments in PBX technology. However, this approach is still very much in an evolutionary stage as associated standards and codecs continue to evolve. When these issues have been resolved, the IP trunking approach will bring mission critical reliability, least cost routing, class of service differentiation, and reusable redundancy features to IP telephony. Just as the potential for IP telephony is huge -- the possibilities for its implementation are endless.

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Brian Allain, Vice President, Internet Business Systems, Lucent Technologies
Kathy Meier, General Manager, Internet Communications, Lucent Technologies
Internet telephony is growing in a universe where users and potential users can select from a wide array of communications systems. Their requirements run the gamut from managing complex call centers to handling telephone traffic in small offices. Depending on the solution a customer selects, voice over IP has numerous benefits, including reducing long-distance costs and allowing customers to increase the efficiency of their voice and data networks. At least in the foreseeable future, a single solution doesn't necessarily need to "win" at the expense of replacing all others; multiple solutions will be relevant.

An enterprise currently getting great value from its voice communications systems may that find the addition of an IP trunk, which is an integrated gateway in a PBX, is the best and most efficient way of adding the benefits of IP telephony. Such a company might have a critical priority of protecting its investment in its current PBX infrastructure.

Other companies are looking to PC-based gateways to enhance their communications systems. PC-based gateways are becoming more popular with corporations with existing communications systems because they are interoperable with each other. PC-based gateways are also the dream of IT managers who are bringing new open applications on standards-based platforms.

New companies, or businesses replacing an old system, may look to a LAN-based solution upon which to build their entire data and voice communications foundation. The excitement over the innovations around IP telephony have as much to do with choice and flexibility as to the power of the Internet itself. Choice puts the user in the driver's seat and we believe these choices will continue to fuel this excitement for some time.

Of course, in any mixed-unit environment, interoperability is the key to success. The IP trunk must communicate with LAN-based solutions or the PC gateways in the network.

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Kerry Hawkins, Vice President Sales, Vienna Systems
IP telephony is an application and provides the core for additional applications that will prove attractive to business and consumers. As an application it is independent of the delivery vehicle - PBXs, routers, or gateways. As an application, it allows the user to choose the platform most appropriate for the delivery of the service they want both now and in the future. A model that insists that the application only be delivered on a specific vendor's product - in the fashion they envisage - is a model that is the antithesis of IP telephony. This approach leaves us trapped in the same world that has delivered vendor-friendly proprietary networks and the pricing that goes with them.

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Francois de Repentigny, Product Marketing Manager, Clarent Corporation
It depends on the market you are considering. When comparing PC-based gateways with router-based gateways, remote-access-server-based gateways, and PBX-based gateways, the fundamental issue is whether the gateway functionality should be embedded into an existing platform or left as a stand-alone device? The answer will depend on the environment where gateways will be deployed.

In a telco environment, a stand-alone gateway is often the appropriate solution, whether it is PC-based or not, because it is more scalable and flexible. Routers and remote access servers were not initially designed to handle voice traffic; they have thousands of lines of code written to perform other functions. This becomes an engineering burden when one wants to rapidly modify or add features. And given the speed at which this industry is evolving, flexibility is a top priority for telcos.

Today, stand-alone gateways are PC-based. The problem is that PCs have a bad reputation in the telephony world because they are seen as unreliable. However, it is possible to build IP telephony networks with fault-resilient architectures using PC-based gateways. For example, an N+1 gateway redundancy in each node is a very cost-effective way of ensuring fault resilience. We have large telco customers running millions of minutes a month using this architecture.

The internal architecture of a PC-based gateway could evolve into something that relies less on the PC; Clarent is certainly exploring those options. But one fact remains -- stand-alone gateways should dominate the telco market because they are inherently more scalable and flexible.

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Marc Robins, Director of Marketing, Linkon Corporation
First, a little background to my answer. Linkon's offering could really fall into a new, fourth category: An IP Telephony Enhanced Services Platform. Our LinkNet product is based on Sun Microsystems' SPARC-based server technology running the Solaris OS (much more robust than an "off-the-shelf" PC). LinkNet provides telephony switching functions (try switching on a router) and integrates enhanced services capabilities into the gateway itself. For example, LinkNet can answer a call, play back voice prompts, dynamically change compression type used, accept DTMF input, look up records in a database, authorize access to the network(s), and connect the caller to an IP or other alternative network. LinkNet also integrates Gatekeeper functions to monitor performance and maintain network quality of service.

So, in answer to your question, we at Linkon believe that while there is a place for each type of solution, an Intelligent "gateway" solution such as LinkNet provides for the greatest degree of flexibility, scalability, utility and programmability in a technology application space that is still in the formative stages of development. A gateway that can easily adapt to changes in the "standards de jour," that can offer a multitude of telephony signaling options, and that can serve as a communications bridge to the greatest number and variety of users will be able to evolve with the market and win a very large piece of the industry pie.

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Andy Voss, NUERA Communications, Inc.
Many existing types of equipment that have been modified to compete in the VoIP stakes have limitations, which will prevent them from becoming dominant platforms. PBXs offer stability but a poor development environment and no packet data architecture to allow them to operate intelligently in data-dominated networks. Routers support the data environment well but are biased towards the non-real-time, delay tolerant environment for which they were developed, and again are not amenable to control by third-party applications. CTI equipment provides an excellent development environment but has inherent flaws of being based on operating systems, which were not developed for real-time, high-availability environments, as well as limitations in scalability.

What will prevail ultimately is a new breed of device delivering high-density DSPs and combining the reliability of the PBX with the programmability of CTI. Nuera views these new devices as "communications computers" exceeding the reliability of PCs or access concentrators, and which come from the manufacturer preloaded with basic functionality -- but with the ability to run applications from many third-party developers.

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