Integrated Services Digital Network (ISDN) is a high-speed digital phone line technology. Data rates over ISDN--128 kbps for a typical installation--are considerably higher than the best that can currently be achieved (28.8 kbps) with traditional modems over dialup analog lines. An added plus is that the existing copper wire phone lines in your home or business usually work just fine for ISDN.
I recently went through a lengthy and painfully frustrating process of having the phone company install an ISDN line. At times it seemed they had no idea of how to install it. Therefore, when this book arrived, I received it with a warm welcome and much anticipation. (To be fair, once we overcame the installation problems, ISDN lived up to its hype. It now provides us with considerably higher throughput than our previous analog lines, at reduced cost.)
The first part of the book introduces just enough ISDN concepts to make the rest of the material understandable. Using ISDN to access the Internet requires two types of interactions: those with the phone company and those with the Internet service provider. The book contains practical advice in both areas. It describes available ISDN services; gives typical costs; and discusses equipment that must be installed at your site and presents configuration options for it. The book also discusses how to pick an appropriate Internet service provider that supports ISDN.
The book clearly states what must be done, sometimes as a series of steps to follow, other times as a checklist of items to cover. (If you are having an ISDN line installed, take care to obtain all the line configuration information called for in Figure 5.1, a lesson we learned the hard way.)
The second part of the book (chapters 6 through 9) expands on the concepts introduced in the first part and goes into some depth on how ISDN protocols are implemented. Valuable as reference material, this part provides more detail than many readers may care about. They can probably safely pass over it. However, readers should not skip the appendices in Part 3. The material there provides valuable information on available services and products and describes how an ISDN line should be configured on a product-by-product basis.
This book is not written in the long-winded, chatty style common to many Internet books. Thus, readers may be surprised to find that a serious book, authored by experts, can be clearly written and well organized. If there is fault to be found, it is that more discussion is needed on whether to request one or two phone numbers for an ISDN line. A standard configuration combines two digital B channels into a single 128 kbps connection. Each channel can have its own phone number, or there can be a single phone number for the line. Only the appendices touch on this subject, and then only for some products. Apparently, this decision is also a function of the switching equipment used at the phone company.
Although this book would not have solved all of the problems we encountered in having ISDN installed, it would have helped. If you are considering ISDN for your Internet connection, you would be well advised to read this book first. Maybe the phone company should read it too.