This book constitutes the refereed proceedings of the Thyrrhenian International Workshop on Digital Communication, IWDC 2001, held in Taormina, Italy in September 2001. The 46 revised full papers presented are a mix of invited papers and selected submitted papers and reflect the state of the art in multiservice IP network research and development. The book offers topical sections on WDM technologies for the next generation Internet, mobile and wireless Internet access, QoS in the next generation Internet, multicast and routing in IP networks, mulitmedia services over the Internet, performance of Internet protocols, dynamic service management, and source encoding and Internet applications.