Network simplification preserving bandwidth and routing capabilities

We introduce structural transformations that allow simplifying a given network while preserving its original 'bandwidth' and 'routing' capabilities, transparently to specific allocations. We minimize a certain objective such as the aggregate capacity of network links, number of nodes, or number of links, in such a way that all the bandwidth that could be routed in the original network can also be routed in the reduced one. This improves cost-efficiency for both inter- and intra-datacenter connections and simplifies network management. We also identify a fundamental tradeoff between extra added capacity and simplicity of representation for a given network. Our analytic results are supported by extensive simulation results on hundreds of real network topologies. One result is that by adding 10-30% extra capacity to evaluated real-world networks one can simplify them down to a star topology with a single switch, while all routing and bandwidth allocation decisions on the simplified topology can be mapped back to the original network. This is an important step towards simplifying network management via a reduced virtualized network infrastructure.