Protection Algorithm Based on Lightpath Load in GMPLS Optical Networks

In this paper, we study survivability in GMPLS optical networks and propose a new algorithm called Protection based on Lightpath Load (PLL) to tolerate the single-fiber link failure. Based on the parameter, Boundary of Heavy-load Lightpath (BHL), PLL can effectively choose the protection execution whether on optical layer or on IP/MPLS layer, such that the bandwidth utilization ratio and recovery complexity can be compromised. In PLL, if the number of Working Label Switching Paths (WLSPs) carried on a Working Lightpath (WLP) exceeds the value of BHL, this WLP will be protected in optical layer; otherwise, these WLSPs carried on this WLP will be protected on IP/MPLS layer. Simulation results show that, compared to conventional algorithm, PLL not only can significantly reduce the recovery complexity but also can obtain satisfactory trade-off performance.