This book is an entry-level introduction to Carrier Ethernet, intended for anyone new to Carrier Ethernet, including those with little or no background in computer networking and/or telecommunications. It has two aims: (1) to explain networking technology leading up to and motivating Carrier Ethernet and (2) to explain Carrier Ethernet conceptually within this framework. This book was conceived to be a prequel to Fujitsu's MEF-CECP Study Guide (any edition), but can be used alone (as an introduction to Carrier Ethernet) or in combination with other professional certification training materials. Carrier Ethernet emerges in the overlap between two highly evolved realms of commercial networking technology: (1) enterprise1 computer networking and (2) telecommunications networking. At one time these realms were very distinct, but for some years now they have been evolving toward convergence. Many professionals interested in Carrier Ethernet lack fundamental knowledge in one or both realms, as well as a clear framework for understanding their convergence and Carrier Ethernet's place in the evolution. Training resources for Carrier Ethernet professional certification tend to assume significant background knowledge and focus on mastering the details needed to pass an exam over core fundamentals and motivations. This book is designed to complement such material, focusing instead on explaining the big picture, the core background technologies, the context, the motivations, and the concepts that underpin Carrier Ethernet. The main goal is to impart a strong foundation for understanding Carrier Ethernet in a general sense. A secondary goal is to offer insights into the evolution of networking technology and the issues that surround and motivate Carrier Ethernet. Chapter 1 provides a synopsis of the book and a brief explanation of Carrier Ethernet. Chapter 2 explains Ethernet in local area networking, starting from first principles and simple contexts and gradually building up to include MAC bridging and VLAN bridging. Chapter 3 describes traditional Telecom technology and wide area networking solutions prior to Carrier Ethernet. Chapter 4 provides a high-level overview of Carrier Ethernet. The appendix includes supportive details related to various of topics covered in the book. This 2nd Edition of the book was published mainly to change the book's subtitle.