CT Plug & Play

Despite the obvious potential for CTI technology, despite the work by the pioneers of the CTI industry over more than a decade, and despite the tremendous excitement surrounding each new hardware or software technology that promised ubiquitous CTI, the use of CTI technology has only now begun to grow dramatically. Overall, the principal barrier to dramatic growth of the CTI market has been the lack of interoperable products. Without this interoperability, developers must specialize their products for very precise configurations, and customers cannot rely on anything they purchase and integrate themselves (as is the normal practice for mainstream computer products). There are many, many ways to differentiate CTI products--but interoperability should not be one of them.


CTI interoperability is best defined in terms of two operational requirements. Specifically, interoperability has been achieved when CTI hardware and software products from any combination of vendors allow the following:

  1. Customers can assemble and upgrade their CTI systems in any fashion using CTI hardware and software products from any combination of vendors. For example, someone can use the same CTI software on the computer at home (connected to an analog residential telephone) and the computer at the office (where there is a digital feature phone desk set). The software takes full advantage of all the capabilities in each location. The customer can even substitute a new CTI server at the office without having to make any changes to the telephone system or application software.
  2. Users of mobile computing devices (laptop computers, personal digital assistants, etc.) can take their devices, and all their software, from one work location to another and still take full advantage of the telephony capabilities in each location, regardless of the combinations of products involved. For example, someone can use the CTI software on her laptop with a pay phone at the airport, the hotel room phone, and the phone at a client's site, as well as her cellular phone.

The Three Phases of CTI Evolution

Consistent with the iterative development of interoperability specifications for telephony, and the maturing of technology in the overall information technology industry, there have been three distinct phases in the evolution of CTI technology:

  1. Custom systems
  2. APIs for everybody
  3. Protocols for systems, APIs for applications

Each phase represents a paradigm shift in the approaches used to develop CTI solutions. Each shift was based on changing economics, technology, and priorities in the telephony, computer hardware, and software industries. The products and practices associated with each phase will continue to exist and interoperate for some time to come. The economics and opportunities associated with developing products for the third phase, however, will mean that more and more industry investment and activity migrates to this approach.

CT Plug & Play

The term CT Plug & Play refers to the ability to take two CT products out of the box, hook them together, and have them work together without having to install special "driver", "mapper", or other proprietary software in either.

CT Plug & Play is made possible by the CT protocols of the third phase. The use of CT protocols allows one device to negotiate automatically with other devices to determine their CT capabilities, so that no effort is required beyond instructing one to connect to the other.

In the paradigm of the second phase, telephone system vendors have to develop special pieces of software that allow a computer to work with the CT interfaces on their products. If these pieces of software are not installed in the appropriate devices, or do not exist, the products simply will not work with one another.

With CT Plug & Play products, standardized CT protocols allow different CT Plug & Play products from different vendors to be combined to form highly customized CT solutions and systems. CT will be truly ubiquitous when all CT products are CT Plug & Play.

© Copyright 1996-2004
For more information, contact Michael Bayer at Computer Telephony Solutions