The goal i have set with this book was to share with you the knowledge i have acquired over six years of OTDR use.I will devote a large part of my work to examining OTDR traces explaining each event in detail, as i consider necessary to evaluate a great number of traces to become an expert in this field.I have also seen fit to investigate each of the sections of the manual with practical examples drawn from my own work activities as this is, except for the theoretical introduction, a manual focused on field practice.Mr. Simone Cavigli and Mr. Nico Marmorini