As the wavelength division multiplexing (WDM) technology matures and the demands for bandwidth increase, survivability becomes more and more important in generalized multi-protocol label switching (GMPLS) controlled intelligent optical networks (IONs). There are great interests to study the performance of restorability under one certain connection management strategy. And studies in the problem of providing recovery from link failures under two different resource reservation schemes, forward reservation protocols (FRPs) and backward reservation protocols (BRPs), are presented. They are examined from the point of view of connection blocking probability, restorability and average recovery time. The two different connection management schemes and the survey of different recovery schemes are first presented. The performance of these recovery strategies is analyzed and compared both through theoretical analysis and simulation results. The main stressed idea is that using BRPs gives the best performance in terms of restorability and blocking probability in restorable GMPLS networks. As the wavelength division multiplexing (WDM) technology matures and the demands for bandwidth increase, survivability becomes more and more important in generalized multi-protocol label switching (GMPLS) controlled intelligent optical networks (IONs). There are great interests to study the performance of restorability under one certain connection management strategy. And studies in the problem of providing recovery from link failures under two different resource reservation schemes, forward reservation protocols (FRPs) and later reservation protocols (BRPs), are presented. They are examined from the point of view the connection blocking probability, restorability and average recovery time. The two different connection management schemes and the survey of different recovery schemes are first presented. The performance of these recovery strategies is analyzed and compared both through theoretical analysis and simulation results. idea is that using BRPs gives the best performance in terms of restorability and blocking probability in restorable GMPLS networks.