Customer Reviews

End-to-End DSL Architectures

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This book provides an interesting in-depth look at DSL architectures and technology. It begins with an introduction to DSL and competitive technologies, and discusses the different varieties of DSL along with ADSL modulation techniques. After a brief review of electrical signal characteristics and the basic telco infrastructure, DSL specific technical issues are looked at such as cross-talk and interference, and impairments in the infrastructure itself, like load coils and impedance mismatches. These DSL architecture challenges and their associated mitigation techniques; automatic rate adaptation, SNR margins, and error correcting algorithms are discussed at length.

TCP/IP and ATM technologies are then reviewed quickly, as well as an exploration of Cisco's Easy IP, before an in-depth look at the main six end-to-end DSL technologies and their enabling protocols is begun. IRB, RBE, the increasingly popular PPPoE, and MPLS are all examined to name just a few. Implementation considerations as well as deployment advantages and disadvantages of the main 6 are discussed.

The Cisco line of DSL products is looked at next, starting with customer premise equipment (CPE) in the home or small office environment. Product offerings such as the SOHO 70 and Cisco 820 series of routers are examined first, leading up to an in depth look at the products designed for the exchange or central office environment like the Cisco 6000 series of layer 2 DSL Access Multiplexers (DSLAMs) and layer 3 IP-DSL switches. Cards, modules, and chassis configuration options are covered.

The next major section of the book briefly reviews AAA, SSG, and the Radius security protocols, before delving into probably one of the more important, and lengthy chapters of the book, Cisco IOS Configurations. This chapter leads one through the construction of an end-to-end DSL architecture implementation from the CPE device to the central office core device. Each step of the configuration process on each device is carefully explained, complete with plenty of IOS configuration examples to clearly illustrate the concepts presented. Some advanced programming topics and fail-over / redundancy planning and configuration, are also presented toward the end of the chapter.

The book finishes up with a discussion of Cisco's graphical management system for IP DSL devices, the Cisco DSL Manager (CDM). CDM deployment, device management, device monitoring, and fault / performance management are all examined

Overall, this book serves as a welcome addition to any technical bookshelf. Whether a seasoned DSL technical expert looking for that book for occasional reference, or a beginner looking to learn the ins and outs of DSL technology, the book is well written for both audiences. The book provides both real world examples and enough technical background information to thoroughly examine all topics covered. For those looking to take one of the applicable Cisco technology exams, the book also provides over 100 insightful and challenging questions to test your knowledge and prepare for the exam.

No doubt explaining the access and aggregation network -where legacy and emerging technologies intermingle based on business, regulatory and technology factors- is a very ambitious topic.

For the most part, this book provides a great introduction to the subject matter that allows the reader to see where the different puzzle pieces fit. If there's a better book that truly provides a deeper insight into DSL architectures, I haven't found it.

There are aspects that could be improved, especially when it came to the part I was interested in the most, the discussion of IRB, RBE, PPPoE and L2TP. The different subsections were a bit inconsistent in their explanations, sometimes going through the protocol stack graphically, sometimes not (unfortunately), sometimes using terminology between figures and text that did not match up 100%. That part looked a bit patched together from different sources, but nevertheless, despite that flaw, it provides the best summary of these technologies in 30 pages or so I have seen anywhere.

Given the fact Cisco seems to have retired its DSLAM product line the lengthy discussion on it seems a bit superfluous, plus it does not add a lot to the understanding of the network architecture concepts I wished to gain from this book.

In summary, I'd buy the book all over again, and if the author decided to revamp it (it's still in the first edition from '03) this could evolve to be a very good reference book on access and aggregation architectures for wireline telcos.

Compiled and edited by technology knowledge transfer expert and specialist Wayne Vermillion, End-To-End DSL Architectures is a straightforward guide to exploiting Digital Subscriber Line services to save time and money in one's business software architecture. Individual chapters address the basics of DSL technology, advice for planning the evolution of one's network, guidelines for implementing DSL technology anywhere in any network, step-by-step instructions, a wealth of information specific to all DSL varieties around the world, all six architectures that implement DSL with TCP/IP, solutions to common problems and much more. Enhanced with "bonus appendixes" providing an overview of ATM as well as a tour of Cisco Long-Reach Ethernet, End-To-End DSL Architectures is a highly recommended instructional resource and reference.

If you are looking for a book that covers poorly drawn conclusions and pitiful insite into the actual technology of DSL, then this is your book. I only hope my kids aren't forced to read this type of stereo instruction manual to better themselves in the world. The author has no technical knowledge of the subject matter at hand and I got the distinct impression that there was a technologist next to him spoon feeding him buzz words.