Improving routing scalability in networks with dynamic substrates

We consider routing between large collections of interconnected networks, referred to as substrate networks, which do not assume permanent connectivity to the Internet, and which support dynamic changes of connectivity due to mobility. Whereas scalable routing schemes, such as compact routing or greedy forwarding, are suitable for very large networks, they generally ignore the routing methods already available in the substrate networks. In this paper, we present a routing scheme, referred to as Landmark domains routing (LDR), which maximally exploits available routing in the substrate networks, and establishes paths between connected regions of substrate networks. We analyze the scheme by numerical analysis and simulation, and compare its performance with compact and greedy routing methods. We demonstrate that leveraging existing routing can lead to a significant reduction in the required routing state information, while providing paths that are, on average, close to the lengths of shortest paths.