This book investigates survivability schemes for optical networks that rely only on a single layer, as well as for those that have more than one layer survivability functions and uses different approaches to solve QoS survivability related problems. We have simulated the restoration process of single transport layer: IP; ATM; SONET and OTN, which have been analyzed by similar studies. Also, we have simulated the process of the multi-layer restoration schemes for previously analyzed IP/SONET, IP/OTN and IP-MPLS/OTN by using the hold- off timer concept. We have extended their restoration concept and applied it for IP/OTN and ATM/SONET restoration schemes. Further more, we have introduced IP Restoration/OTN Protection combined multi-layer survivability, IP Restoration/SONET Protection combined multi-layer survivability and IP- MPLS Protection and Restoration/OTN Protection combined multi-layer survivability. In this book, we have combined the analyses with simulations to form a comprehensive study. We focused on four of the most commonly used IP over OTN architectur possibilities: IP/POS/OTN; IP/GbE/OTN; IP- MPLS/OTN,and IP/ATM/SONET/OTN.