Survivable MApping Algorithm by Ring Trimming (SMART) for large IP-over-WDM networks
We develop a fast and efficient algorithm that finds a survivable (i.e., robust to single fiber failures) mapping of IP topology on the mesh of fibers in IP-over-WDM networks; we call it SMART. A number of algorithms solving this problem can be found in the literature. Since ILP solutions are highly complex, many heuristics were proposed. They usually start with some initial mapping and then try to gradually improve it. This involves the evaluation of the entire topology at each iteration, which is costly for large topologies. We propose a different approach. The SMART algorithm breaks down the task into a set of independent and very simple subtasks. The combination of solutions of these subtasks is a survivable mapping. This is why SMART is orders of magnitude faster than other proposals, especially when dealing with large topologies. We also extend the SMART algorithm to obtain a mapping resilient to fiber span failures, node failures and double-link failures. Finally, we show that the scalability of the standard heuristic approaches is additionally limited (contrary to SMART) when applied to double-link failures.