Optical networks are leaving the labs and becoming a reality. Despite the current crisis of the telecom industry, our everyday life increasingly depends on communication networks for information exchange, medicine, education, data transfer, commerce, and many other endeavours. High capacity links are required by the large futemet traffic demand, and optical networks remain one of the most promising technologies for meeting these needs. WDM systems are today widely deployed, thanks to low-cost at extreme data rates and high reliability of optical components, such as optical amplifiers and...

IP is clearly emerging as the networking paradigm for the integration of the tr- ?c ?ows generated by a variety of new applications (IP telephony, multimedia multicasting, e-business, ...), whose performance requirements may be extremely di?erent. This situation has generated a great interest in the development of te- niques for the provision of quality of service (QoS) guarantees in IP networks. Two proposals have already emerged from the IETF groups IntServ and Di?- Serv, but research and experiments are continuing, in order to identify the most e?ective architectures and protocols. The...