Quite simply, this is the ultimate text on ISDN. The authors are to be commended on a thorough and readable presentation that goes far beyond what is normally considered ISDN. The book begins with introductory and background material and then moves quickly into ISDN fundamentals. Narrowband ISDN concepts, services, and protocols are presented. There are chapters on the physical layer protocols and configurations, as well as on data-link layer protocols (in the D-channel). Next is a chapter dealing with packet versus frame mode services. There are chapters dealing with the future of ISDN as a national telecommunications environment, including applications and products based on ISDN. There is even a chapter on Signalling System 7, which is key to ISDN interconnection.

Happily, this is only the first half of the book. It is really only the beginning, if one thinks in terms of modern telecommunications technologies. Narrowband ISDN is an important initiative, but it only scratches the surface of what is possible with modern digital systems and services. There are two chapters on frame relay; three chapters on asynchronous transfer mode (ATM), which is the transport mechanism for broadband ISDN; and a chapter on switched multimegabit data service (SDMS). The book ends with a discussion of these technologies in the context of the Internet. Additionally, useful appendices explain common ISDN acronyms and ISDN technical specifications and recommend additional sources of information about ISDN.

No one interested in networking, whether practitioner or academic, should be without this extremely well-done text.