End-to-End DSL Architectures
Reviewer Name: Dan Maunz, Assistant Vice President
Reviewer Certification: CCNP
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 more than 100 insightful and challenging questions to test your knowledge and prepare for the exam.