This book is intended for users of any type or brand of telephone system, computer, or operating system. To avoid any bias in the illustrations used throughout the book, all diagrams use stylized
icons to represent the various components of a system. References to particular products are made only when the product in question represents a recognized, de facto standard.
Use this book as a resource to help you identify your CT opportunities; determine the way that you want to approach CT; identify the type of solutions, products, or components you want to assemble or build; and assess your needs and preferences. Armed with the insights you'll have, you can identify the products and the strategies that best satisfy your needs.
If you wish to delve into greater technical depth, or wish to arm yourself with specific details from the applicable published standards and specifications, you will find the included CDROM to be a natural extension of this book. The CDROM is packed with specifications and information of use to application developers, product designers, and those who must specify system requirements. If you are interested in developing CT products, you may also wish to consult the bibliography at the back of this book for a list of other valuable development documentation.
The pace of new product development in the world of telephony and CT is so rapid that product-specific information is not included here; it would become obsolete far too quickly. To find out about the latest in available products, you might wish to:
• Contact your existing telephone equipment vendor(s);
• Subscribe to industry magazines;
• Monitor the efforts of groups such as the ECTF (their web site is at http://www.ectf.org);
• Attend industry trade shows; and
• Check the author's web site at http://www.CTExpert.com.
In particular, updates to the material in this book will be regularly posted to the web at http://www.CTExpert.com/book.
Chapter 1
What Is Computer Telephony?
Telephones and computers indisputably are the two technologies that most greatly impact every aspect of our daily lives. These technologies are central to the operation of virtually any business of any size. A vast number of organizations exist only because of these technologies.
In fact, one could argue that these are the technologies that hold together the very fabric of the modern information-oriented economy. Computer Telephony, or CT, brings these two
technologies together and harnesses their synergy.
The telephone network is a tremendous resource, of which everyone should be able to take full advantage. Telephony1-1 technology, the technology that lets people use the telephone
network, is extremely powerful and has great potential for empowering people in every walk of life.
For the vast majority today, however, the only means of accessing the telephone network is through a telephone set or answering machine of some sort. The one thing all these devices have in common is their
1-1 Telephony — Incidentally, the word ''telephony" is pronounced "teh·LEF·eh·nee." It should not be pronounced "teh·leh·FOH·nee" as this generally leads to some embarrassment.
arbitrary and very limited user interface. The telephone set is a terrific device for getting sound into and out of the telephone network, but it is a very poor device for getting access to
powerful technology. Even the simplest features are rarely mastered by the average telephone user. All too often you've heard someone on the telephone say, "I'll try to transfer you
now—but if this doesn't work, here's the number to call."
Figure 1-1
Without CT and with CT
Personal computers, the Internet, fiber optic networks, speech recognition software, and other revolutionary information technologies are reshaping how we live and work. Organizations are anxious to put these new technologies to use. However the full potential of these new
technologies can only be realized when they are integrated with the telephone system. Yet just as telephone systems have offered limited interfaces to individual users, they have
traditionally offered little access to those who wish to customize them to their own specific requirements.
Computer telephony changes all of this. CT provides an alternative means of accessing the power of telephony technology. Computer technology is an empowering technology because it allows people to extend their reach, and it can take on time-consuming or non-creative tasks.
Computer technology allows for tremendous customization, so that you can have a user
interface and work environment that is optimized for your needs. With CT, this means you can have full access to the power of the telephony technology you need, and have it in the form that is best for you. A computer working on your behalf can take actions independently, so it effectively becomes your assistant. With CT technology, this means your computer can screen calls, handle routine requests for information without your intervention, and interact with callers in your absence. As shown in Figure 1-1, CT technology not only gives you full access to telephony technology, it actually amplifies its utility!
The following examples illustrate how computer technology has the power to amplify the power of telephony and make it more accessible.
• At a pay phone:
- Without CT, you have to laboriously enter your carrier preference (if you can remember the access code), credit card information, and number you want to dial.
- With CT, you simply point your personal digital assistant (PDA) or laptop computer at the infrared (IR) port on the pay phone and click on a person's name. In fact, if you'll be there a while, you can have selected calls rerouted from your office number to the pay phone, which would in turn alert you with information about each incoming call.
• At home:
- Without CT, you're in the living room watching TV and you remember that you have to talk to a colleague (who is traveling on the other side of the world) before he leaves his hotel. You head for the phone in your den, look up the number for his hotel, look up the country code for the
country where he is traveling, and the access code. After you have dialed all of the digits correctly (on the second or third try) and complete your short conversation, you jot down a note to yourself as a reminder to expense the telephone call when you get your next bill.
By the time you get back to the living room, you've missed the rest of your TV program.
- With CT, you wait for the next commercial break and then, with your TV's remote control, you pop up your personal directory as a picture-in-picture on your TV set and select your colleague's name. The TV then displays a set of locations, including the hotel where he is staying. You select the hotel and indicate you want to dial the number. The appropriate number is dialed automatically (using the cheapest available carrier); your TV then acts as a speaker phone, allowing you to converse with your colleague without
leaving your seat. When the call completes, you return to your TV program. Information about the call is logged to your home finance package as an expensable item.
• While telecommuting:
- Without CT, you appreciate the opportunity to work at home as a means of avoiding the long commute and the other inefficiencies of work at the office. Unfortunately, however, it means you miss many important telephone calls that then wind up in your voice mail box at the office. You don't want to forward the calls home because you don't want them inadvertently being directed to your family's residential voice mail system.
- With CT, your home personal computer has a remote connection to the local area network at your office, allowing you to monitor your telephone. If an important call
comes through, your computer notifies you so you can decide whether you want it to go to voice mail or be redirected to your home telephone. Using Internet telephony, you can take the call even if your phone line is busy. In fact, the system
works so well that even the call center agents in your company, who spend their whole day handling customer telephone calls, are able to work from home.
• At the office:
- Without CT, you are trying to cope without the administrative support you lost through organizational downsizing. Throughout the day calls pile up in your voice mail box instead of being directed to people who could take care of callers right away. You place many telephone calls yourself, and when you need to reach someone, you spend a lot of time placing calls—only to get their voice mail systems, and you end up having to try again later.
- With CT, your desktop personal computer has taken the place of your secretary. Using CT technology, it screens every call that comes in. If you're busy, you aren't disturbed. If the call is best handled by someone else, it is redirected without your intervention. When you need to get hold of someone, your personal computer will keep trying until the person is reached; only then does it connect you to the call, so you aren't tied up doing the
redialing yourself.
• In the school:
- Without CT, there are just three telephone lines in the whole school and they can be accessed only from the principal's office and from the staff room. Despite the fact that teachers believe students would benefit greatly from the ability to use telephones as a resource for research and other projects, there are no telephones in the library or in the classrooms because there is no way of controlling their use.
- With CT, the school has an Internet telephony gateway and each of the computers in the classrooms and the library are equipped with speaker phone applications. These allow groups of children to sit around computers and place telephone calls to resource people in the community, as well
as children at other schools. The school doesn't need a high-speed connection to the
Internet because most calls are placed using one of the phone lines the school already has.
The school's electronic bulletin board on the Internet, which lists homework assignments and lunch menus, is available not only to parents who have computers at home, but also those who want to dial in from any touchtone telephone.
• In a meeting:
- Without CT, you may miss an important call that you are expecting because you must attend an equally important meeting. You have no secretary and cannot forward all of your telephone calls to the meeting room because it would be too disruptive. You must rely on voice mail to catch the call. You leave the meeting frequently to see if it has come through and then you try to return the call.
- With CT, your personal computer checks the origin of each call and identifies the important call when it arrives. Rather than simply taking voice mail, it tells your caller that it will try to track you down. It then sends a notification to the wireless PDA (personal digital assistant) you are carrying. This notification tells you who called and informs you that the caller is holding. You can respond by instructing your computer to take a message, hold the call while you return to your desk, or transfer the call to a nearby telephone. The others in the meeting are not even aware that you are having this wireless dialog with your desktop computer.
The ultimate promise of information technology is that it empowers people to collaborate with one another more effectively and with greater ease. Since the invention of the telephone over a century ago (in 1876), telephony technology has evolved tremendously. Innovation was fast and furious in the earliest days after Alexander Graham Bell's invention; it took less than two years to commercialize the technology. To this day the pace has not slowed. While modern computer technology is a much more recent invention, its history has been just as
fast-paced. The key to both disciplines is their ability to improve the ways people
communicate and collaborate, because these activities are at the heart of all human endeavor.
This book differentiates between "CT technology" and "CT solutions." This book covers all the concepts and details you need to know about CT technologies, and then illustrates how these technologies are applied in typical CT solutions. These terms are further explained in section 1.11.
1.1 The Importance of Telephony
The telephone is the single most important communication appliance in the world today.
Despite the high levels of acceptance for various other forms of information technology, including consumer electronics products and personal computers, the telephone (in all of its forms) remains the only communication device that can be considered ubiquitous.
Figure 1-2
Everyone you want to talk to is somewhere on the telephone network
The telephone network is the single most important network in the world because:
• There are more "endpoints" on this network than any other (counting just the number of telephone sets).
• The telephone network requires the least effort to use because its basic format is voice.
Virtually any human being on the planet is able to interact with any other through the telephone network.
• The telephone network acts as both the on- and off-ramp, and as the interconnection
between, most other networks in the world. In fact, there are very few people, fax machines, computers or data networks in the world that cannot be reached through the worldwide telephone network (Figure 1-2).
1.2 The Importance of Computers
The "C" in "CT" stands for "computer." This may be a little misleading, though, because the word computer is being used here in its broadest sense. The term refers to any device that can be programmed to control or observe telephony resources. Think of it as any device using
"computer technology." While this set of devices certainly includes traditional mainframes and minicomputers, as well as your own personal computer, it also includes many others. For example, PDAs are small, handheld devices that generally have much less power than traditional computers and a more limited set of uses. But as personalized information appliances, PDAs are very important when it comes to telephony integration. Similarly, a whole new generation of so-called "intelligent,'' programmable consumer electronics products will transform everyday devices such as VCRs, TVs, watches, games, etc., into what we consider to be "computers" for purposes of CT (Figure 1-3).
Contrary to popular wisdom, the diversity of computing devices continues to grow as computer technology becomes more pervasive and more specialized. In the early days of computer technology, a panel of experts is said to have concluded that only a small number of