This volume aims to bring network managers up to speed on a sea change in the business of providing communications services. 1998 was the year that VoIP finally took off, making the Internet competitive with the public switched telephone network for voice-based communications and conferencing. Amid the welter of Internet communications equipment and service offerings already out in the marketplace and soon to come, network managers need to know what's ready for prime time, which standards are stable, and what's in it for them. Written by the experts at Lucent technologies, this book helps network managers make a well-informed match between product capabilities and the demands of their environments and applications.