Path vs. subpath vs. link restoration for fault management in IP-over-WDM networks: performance comparisons using GMPLS control signaling

We investigate three restoration techniques (path, subpath, and link restoration) for fault management in an IP-over-WDM network. We have implemented all of these techniques on the ns-2 simulation platform using generalized multiprotocol label switching (GMPLS) control signaling. These techniques can handle practical situations such as simultaneous multiple fiber failures, which are difficult to design for and recover from by nonrestoration techniques. We then present performance measurement results for the three restoration techniques by applying them to a typical nationwide mesh network running IP over WDM. We investigate interesting trade-offs in the performance of the restoration techniques on restoration success rate, average restoration time, availability, and blocking probability.