This revision of a first edition [1] covers the field of computer communications at a moderately technical level. It is aimed at the data processing professional, but not necessarily at one specializing in communications or networking. It is comprehensive, touching on most (but not all--see below) important topics; yet it remains at a high enough level to avoid losing the average reader in excessive detail useful only to specialists. Those new to the field, and those with just a passing interest in it, will appreciate this intermediate level of detail. Those already skilled in the field will probably have less use for the book, except in a few specific areas unfamiliar to most technical specialists.

The book covers all the usual topics covered by similar books on this subject: communications media, signalling techniques, error control, and data link protocols. Most of these topics are treated in considerable depth. Adequate coverage is given for both wide area networking and LANs. All these topics are clearly and coherently described in a manner that is a welcome relief from the mathematical formulas commonly found in discussions of physical transmission. The book also has a useful discussion of the roles of various standards organizations and common carriers important to the communications industry and a discussion of standards like ISO, SNA, and IEEE 802 LAN protocols. The chapter on network design considerations will interest those wondering how the experts decide on physical network layouts and communications line loading, but it does not get into higher-layer protocol design issues. The chapter on current events in communications and the implications of the AT&T divestiture is a bit uncommon but perhaps interesting.

The two chapters on databases and distributed systems are most unusual. These chapters seem out of place, as they describe software design while most of the rest of the book covers topics closer to the hardware. Database design in particular is not a networking topic. While software plays as important a role in networking as does hardware, these chapters are too much of an overview and give the reader little more than a hint of the issues in software design. Whole books can easily be written on database design, and additional books are needed to discuss distributed databases, even at the same general level of detail at which this book covers other networking issues. While the introduction to the problems of distributed database design is good, the reader whose interest is in distributed databases will be better off with a more specialized reference. Despite the justification for covering these topics suggested by the preface, these chapters are likely to be skipped by most readers of the book. The space might have been better utilized with an in-depth treatment of the communications protocols that are a more fundamental part of networking.

Issues in higher-layer protocol design (protocols at the ISO network, transport, and higher layers) tend to receive inadequate treatment in books claiming to be about networking, and this book is no exception. Transport protocols and other end-to-end protocols are covered in fewer than ten pages of this book, yet the vast bulk of networking software in computer systems is written to support such functions. Application layer functions now pervasive in the industry, such as electronic mail, are not mentioned at all. No one should fault a book of this size for not treating such topics thoroughly. But readers should be warned that the book will leave them unsatisfied if they want to learn about higher-layer protocols.

Another notable omission in this book is security. While network security is another large topic that would require a whole book to cover in depth, it is important enough to be given more than passing mention.

The field of networking has gotten so big that it is no longer possible to produce a single volume that adequately covers all areas. A book attempting to do so will necessarily treat certain areas in a superficial manner. As with all books, there is a specific target audience to which this book will appeal most. That target is composed primarily of beginners who want a well-rounded treatment of the fundamental aspects of computer communications prior to involvement in a specialty.