With this fourth edition of the best-selling book Data Communications and Networking, Behrouz Forouzan once again presents a comprehensive and accessible approach to networking theory and applications. His visual approach features excellent illustrations and clear explanations that guide students through difficult concepts. This unique approach minimizes the need for heavy math content, allowing normally complicated topics to unfold more intuitively. The abundant pedagogy spread throughout the book helps to reinforce learning. More than 700 figures, real-life applications, worked examples, and many new practice problems all contribute to the text´s presentation. In order to stay abreast of the rapid technological changes in the networking field, several organization and content changes have been made in this new edition. An entire chapter is now devoted to network management in the Internet. Also, in response to the growing importance of security, the newly revised Chapters 30, 31, and 32 focus on the most up-to-date security issues in relation to the Internet and networking. Multiplexing, SONET technology, IP addressing, and additional coverage on switching have all been newly integrated into the text. Forouzan´s student-friendly approach has been lauded as easy to use and easy to read, and this new edition ensures that the fast pace of networking technology leaves no student behind by providing accessible, cutting-edge coverage.