In this book, experts who helped to write the DSL standards describe the many advances in DSL technology and applications since the writing of their best selling DSL book "Understanding Digital Subscriber Line Technology" published by Prentice Hall in 1999. This book describes the recent technical, architectural, and regulatory developments that enable mass market DSL services provided by telephone companies and competitive local exchange carriers (CLECs). KEY TOPICS: Digital Subscriber Lines (DSLs) have transformed millions of humble telephone lines into broadband arteries linking homes and businesses to the Internet at megabit speeds. New developments in ADSL, VDSL, HDSL2, SHDSL, line unbundling, and spectrum management are discussed in detail with highlights from the newest US and international (ITU) standards. Greater breadth than many other books is provided with extensive material on networking within the customer premises, end-to-end network architectures, upper layer protocols, security, auto-configuration, and a chapter on voice-over-DSL methods. MARKET: Networking engineers and technical marketing staff at network equipment vendors, silicon vendors, customer equipment and PC vendors, telecommunications carriers, regulators, industry investment analysts, consultants, graduate students.