A path finding implementation for multi-layer networks

The goal of the OptIPuter project is to tightly couple research applications with dynamically allocated paths. Since OptIPuter is a multi-disciplinary project, the paths through the network often span multiple network domains, and the applications are challenged to find valid network connections through these domains.The challenge arises if the different network domains use different technologies. In this case, we have a multi-layer path finding problem.We will show that there are situations where algorithms as used in single layer networks, such as BGP, SS7 and OSPF-TE, cannot find the shortest path. A shortest path in a multi-layer network can contain loops, and a segment of a shortest path may not be a shortest path in itself.To solve this problem, both a multi-layer network representation as well as new path finding algorithms need to be developed. An additional challenge is to make a generic path finding algorithm that is technology-independent, and does not need to be modified as new technologies emerge.We show that it is possible to create solutions for all three problems. Using RDF-based techniques, we model multi-layer networks and describe incompatibilities for the path finding algorithm in technology-independent way. We also present a path finding algorithm that is able to use this information to find valid paths.