July 1999

A WIDE SCOPE: The View From Atop A CT Server

BY DEAN A. TRUMBULL

In the world of mainstream computing, the open systems model has long been the norm. To use a geographic analogy, open systems and standards have been like bridges and tunnels allowing information "roads" to traverse varying terrains with relative ease. But the world of computer telephony (CT) - made up of separate, often proprietary systems handling functions like voice processing and computer-based fax - has until recently suffered from rifts and mountains that were too broad to cross or too high to scale. This has kept systems expensive and hard to manage, stunting the growth of the CT industry. With some help from system engineers rather than civil engineers, that landscape is changing.

The technologies and industry support are in place today for next-generation systems based on open standards and delivered on a true CT server that allows a wide array of applications from different vendors to share applications and technology resources. Tomorrow's computer telephony solutions will look much more like mainstream computing systems -with simplified development, scalability, easy manageability, shorter time-to-market, and lower hardware costs.

SURVEYING THE LANDSCAPE
Computer telephony began recently where databases were some 15 years ago and is developing according to the same model. Where once the corporate world relied on a wide variety of separate, proprietary database applications, today those separate applications have been replaced by open, large-scale enterprise applications leveraging database services. Why? Because open systems offer dramatically greater value:

• Lower cost of ownership. A single database supports many applications, slashing the cost of the entire system.
• Richer applications. Applications are easier to develop and deploy. A broader market attracts more developers and the cost of development goes down, resulting in greater diversity and more powerful applications.
• Competition-driven price reductions. Continuously lower costs for hardware, software, and services lead to higher volume and low barriers to entering the market with new applications.

The CT server will enable the computer telephony industry to move to the next step in its evolution, just as the database did with the introduction of the database server. Enterprise applications need to leverage communications services — something companies like Siebel, Oracle, and SAP have already discovered. Instead of a proprietary, standalone system, the call center will become a process within a larger customer management application. CT servers also enable the fast-growing market for e-commerce.

HOW OPEN IS OPEN?
While suppliers make many confusing claims of “openness,” most of today’s PC-based PBXs, communication servers, and other computer telephony systems don’t yet pass the test. If you buy from one manufacturer, you can’t run software from another manufacturer on the same platform. This means today’s systems still tend to be single-function systems tied to a specific manufacturer’s hardware, since the software must be written to the manufacturer’s proprietary API.

Developing an application based on a specific hardware component becomes even more complex when the system integrates hardware from multiple suppliers. The applications become tied to each component supplier’s individual interface.

The result? If you purchase a system from one vendor, you are essentially tied to that vendor, forced to use its technologies and hardware platform. Or, if you really want to make two systems from different manufacturers communicate, you pay heavily for custom systems integration. Making any kind of system change can impact an unknown number of tenuous interdependencies among the numerous products in the system.

The unavoidable dependency on hardware for this type of system limits the system designer’s options for upgrading and enhancing features. Plus, having several separate single-function systems makes them hard to administer.

CHANGING THE LANDSCAPE
So how do we go about solving these problems? Instead of deciding how to build a better PBX, it is more reasonable to focus on moving from a special-purpose system that is great for basic telecommunications to a general-purpose box that is not only useful for basic telephone communications, but can be extended to host a range of related services like messaging, automated processing of phone-based transactions, fax services, and more. This general-purpose box is a CT server, a multi-purpose platform that can support many types of services, bridging computing technologies with telecommunications services.

A standards-based CT server completely changes the landscape. For developers, applications are easier to design and quicker to bring to market since there’s no need to write code to handle low-level resource management. Developers can concentrate on new features like specialized routing rules or more sophisticated reporting functions.

Also, since software from multiple vendors can share server resources, developers can offer MIS managers systems they can expand with new services at a much lower cost. Users also benefit from the CT server, getting maximum value for their investment in a hardware platform, enjoying a wider choice of interoperable software, and making the telephony services and technologies on the server available to their other network applications.

ANATOMY OF A CT SERVER
In general, a server is a shared computer on a local area network that distributes resources to any number of client PCs on users’ desktops. Open systems client/server computing has become the preferred way to deliver mainstream applications like e-mail and databases to corporate desktops, saving money and simplifying maintenance and upgrades. The keys to making client/server computing work include application interoperability and open, standards-based platforms like Windows NT and Unix.

A true CT server works much the same way. It supports multiple applications from different vendors on a wide variety of hardware platforms. Built with standard APIs like TAPI and S.100, the CT server is easy to expand by adding new services incrementally. Because it is standards-based, it is also tightly linked to general IT applications. A completely open system, it lets users choose from best-of-breed applications from numerous vendors. With shared resources and full integration, it is also easy to administer and expand.

CT SERVER CONSIDERATIONS
Today, the technology exists to build a true CT server. Even so, there are many factors to consider in building a server that can unite today’s separate applications and resources.

First, every component of the CT server must be based on key standards from established industry organizations. These include the Enterprise Computer Telephony Forum (ECTF), International Telecommunication Union (ITU), American National Standards Institute (ANSI), European Computer Manufacturers Association (ECMA), Institute of Electrical and Electronic Engineers (IEEE), and International Organization for Standardization (IOS). Key standards for applications include S.100, TAPI, and CSTA. For phone sets, the ISDN-BRI standard is essential. And for bus architectures, PCI, CompactPCI, and IEEE1394 are crucial. Also, the CT server must support a wide range of standards-based applications and resources.

To make sure developers are free to put together a system of best-of-breed components from any number of vendors, the CT server must be compatible with virtually any PBX and with the widest possible range of applications. The CT server must also be switch-fabric-neutral, compatible with standards like ATM, TDM, and VoIP standards. It is also essential for the CT server to have a fail-safe architecture — especially if it is to be used in the public network. What happens during a CPU outage? The embedded host must take control. What happens during a power interruption? The CT server must have automatic connections to the PSTN.

Also, the server’s architecture must be scalable. The application should not have to change each time the system expands. That is why software like CT Media is essential to insulate the client applications from the underlying hardware platform, allowing the system to grow as the customer’s demands change. To do this, the CT server must support a wide array of technologies: VoIP, fax over IP (FoIP), ATM, ADSL, and GSM, the standard digital cellular phone service in Europe and other parts of the world.

Finally, it is essential to consider the supplier from whom you buy your CT server hardware. You must be able to count on seven-day-a-week, 24-hour-a-day support and have someone to call whenever there is a problem. You must also be sure your server hardware has regulatory approvals from agencies like the FCC, Underwriter’s Laboratories (UL), the European Community (EC), and the British Approval Board for Telecommunications (BABT).

Dean A. Trumbull is vice president, CT Switch Products, of Dialogic Corporation. Dialogic is a leader in the manufacture of open, high-performance, standards-based telecommunications and computer telephony (CT) components. For more information, please visit their Web site at www.dialogic.com.

CT Media, available now for Windows NT, is an open and standards-based software platform that makes it possible to design a CT server supporting a wide range of messaging, IVR, fax, ACD, and other applications from different vendors. With CT Media, multiple applications developed to standard APIs like S.100 and TAPI can share a common CT server and all its resident technologies. CT Media also provides an open interface to SCbus and ECTF H.100 technology hardware, so it’s easy to add new technologies to the server without changing existing applications.

Industry leaders have shown their support for the CT server concept and have begun cooperating to deliver open, standard CT server technology to businesses of all kinds. For example, Alcatel and Dialogic are developing a standards-based hardware and software convergence platform for small to medium-sized companies. Developed by Alcatel, the communications server will integrate telephony functions, computer applications, and Internet access onto a single platform. Alcatel is working with Dialogic to develop key elements of the Dialogic CT server hardware architecture and CT Media resource management software for use in the communications server, which Alcatel will market.

In another move to accelerate the use of open platforms and standards like TAPI, Microsoft and Dialogic are working together to extend the role of Microsoft Windows operating systems as a platform to enable developers to build open, cost-effective CT and converged communications solutions. Microsoft is licensing Dialogic CT Media server software; Dialogic is providing development services to Microsoft.

The open, standards-based CT server is the future of communications. The technology and industry support are now in place for the next generation of computer telephony systems to be delivered on an open CT server. For developers and end users, this will mean a whole new world with simplified development, scalability, easy manageability, shorter time-to-market, and lower hardware costs.