If you did not know that RADIUS is the "Remote Access Dial In User Service", a challenge and response authorisation access protocol, then you probably would not give this book (and this review) a second glance. The target audience is therefore those who already know basically what RADIUS is and what it can do for them, but need either a tutorial or a reference manual, possibly both.
The first four chapters take the reader from an introduction to AAA (Authentication, Authorisation, Accounting) through to detailed explanation of the base RADIUS message structure and use. There then follows two chapters describing how to configure and use freeRADIUS, an open source RADUIS server. The remainder of the book completes the study of RADIUS by examining other uses, security and new developments.
This book is a good introduction and tutorial and is worth reading before delving into the RADIUS RFCs. It is also a good reference with clear description of RADUIS attributes and a useful attribute reference appendix. However, the RADUIS standard is defined in RFC2058 and the book should be considered a complement to, and not a replacement for, the RFC document.
RADUIS is a base protocol containing many optional elements or context sensitive, it is also intended to be extended by use of the Vendor Specific Attribute. This means that for most uses of RADIUS a description of the base protocol is insufficient and needs to be supplemented with vendor or implementation specific documentation.
In the AAA domain, RADIUS is being superseded by Diameter (RFC3588) and so the RADUIS protocol, and thus this book, is only of use to those already committed to using it.