The explosion of the World Wide Web has created greater awareness of computer networks, and has made understanding network fundamentals and data communications essential. The Second Edition of Shay's best-selling book combines a solid and well-respected presentation of data communications and network fundamentals, with important information on the state-of-the-art developments that support the World Wide Web. New topics include asynchronous transfer mode (ATM), modems, and new topics in encryption and network security. Expanded coverage of LAN/WAN systems and protocols includes the Netware LAN operating system and TCP/IP and IPv4 WAN protocols, with new coverage of the IPv6 WAN protocol. Dr. Shay presents these fundamentals, and a wide array of specific applications, at exactly the right level for Junior CS and CIS majors intending to be information systems professionals.