Building on the successful top-down approach of previous editions, the Fourth Edition of Computer Networking continues with an early emphasis on application-layer paradigms and application programming interfaces, encouraging a hands-on experience with protocols and networking concepts. With this edition, Kurose and Ross bring the issues of network security to the forefront and integrate the most current and relevant networking technologies. Networking today involves much more than standards specifying message formats and protocol behaviors-and it is far more interesting. Professors Kurose and Ross focus on describing emerging principles in a lively and engaging manner and then illustrate these principles with examples drawn from Internet architecture.A balanced presentation focuses on the Internet as a specific motivating example of a network and also introduces students to protocols in a more theoretical context. A chapter on wireless and mobility includes insight into 802.11 and coverage of ad hoc networking. Principles and Practice boxes throughout demonstrate real-world applications of the principles studied. Case History boxes are sprinkled in to help tell the story of the history and development of computer networking. Material on application programming development is included, along with numerous programming assignments. A highly developed art program enhances the descriptions of concepts. A comprehensive Companion Website, which includes additional learning material, links to relevant online resources, and lab material.