Optimal configuration in hierarchical network routing

This paper studies the problem of configuring a hierarchical network routing system, with the objective to optimize its performance. The problem is concerned with optimally partitioning the network routing system into a hierarchy of routing nodes, which are grouped and distributed onto the underlying network. Obtaining an optimal configuration means the minimization of the processing cost (time, memory space, and inter-node communication). The solution to this problem is dependent on the network type, network topology and routing algorithms, and it can be shown that this problem in general is NP-complete. We first describe a general model for optimal configuration of a hierarchical network routing system. Then we identify and discuss several basic heuristics for finding a near-optimal configuration. We also report our on-going study of specific network topologies, e.g., the tree-structured topology, for which efficient algorithms may exist for configuring the hierarchical routing nodes to optimality.