Optical WDM networking technology is spearheading a bandwidth revolution in the networking infrastructure being developed for the next generation Internet. Rapid advances in optical components have enabled the transition from point-to-point WDM links to all-optical networking. This text presents some of the most important challenges facing the optical networking community, along with some suggested solutions. Earlier textbooks in optical networking have a narrower perspective, and rapidly advancing research has created the need for fresh and current information on problems and issues in the field. The volume editors and contributing authors have endeavoured to capture a substantial subset of the key problems and known solutions to these problems. All of the chapters are original contributions from leading international researchers. The chapters address a wide variety of topics, including: the state of the art in WDM technology; physical components that make up WDM fibre-optic networks; medium access protocols; wavelength routed networks; optical access networks; network management; and performance evaluation of wavelength routing networks. The chapters also survey critical points in past research and tackle more recent problems.