This book investigates different approaches for designing and operating an optical network with the objectives that (1) more connections can be carried by a given network, leading to more revenue, and (2) connections can recover faster in case of failures, leading to better services. The book covers different networks and proposes different approaches to explore every aspect of a protection scheme. Tradeoffs between different objectives, e.g., resource efficiency vs. recovery time, are explored and practical approaches are proposed and analyzed.