The Handbook is intended as a guide for technologists, middle-level management, as well as regulators, to assist in the practical installation of optical fibre-based systems. Throughout the discussions on the practical issues associated with the application of this technology, the explanations focus on how ITU T Recommendations address them. It provides the organized insights of those who have created and lived with the evolution of the technology for several decades. Note: The soft-copy of this publication is downloadable free of charge on an exceptional basis, while hard-copy may eventually be purchased.