Providing a detailed introduction to data communications for any computing-science course, this text is designed particularly for students on BTED HNC/D courses in computing, and for undergraduate degree modules in LANs. It is also suitable for professionals and computer managers who are responsible for networking and need a technical awareness. No prior knowledge is assumed, and the concepts and terminology are introduced at the beginning, before understanding is developed on the knowledge gained. The third edition contains new material on ATM, the Internet, Novell and Windows NT, and a wide range of exercises.