Accessing the WAN CCNA Exploration Companion Guide is the official supplemental textbook for the Accessing the WAN course in the Cisco Networking Academy CCNA Exploration curriculum version 4. This course discusses the WAN technologies and network services required by converged applications in enterprise networks. The Companion Guide written and edited by Networking Academy instructors is designed as a portable desk reference to use anytime anywhere. The book's features reinforce the material in the course to help you focus on important concepts and organize your study time for exams. New and improved features help you study and succeed in this course: - Chapter objectives: Review core concepts by answering the focus questions listed at the beginning of each chapter. - Key terms: Refer to the updated lists of networking vocabulary introduced and turn to the highlighted terms in context in each chapter. - Glossary: Consult the all-new comprehensive glossary with more than 250 terms. - Check Your Understanding questions and answer key: Evaluate your readiness with the updated end-of-chapter questions that match the style of questions you see on the online course quizzes. The answer key explains each answer. - Challenge questions and activities: Strive to ace more challenging review questions and activities designed to prepare you for the complex styles of questions you might see on the CCNA exam. The answer key explains each answer.