1. An apparatus comprising a configurable (N+N) multistage interconnection network having N input terminals connected to N output terminals by a plurality of stages, each stage having a plurality of switches, wherein the multistage interconnection network comprises: memory for storing a control-seed value; and one or more permuters adapted to permutate the control-seed value to generate one or more control signals, wherein switches of the multistage interconnection network are configured based on the one or more control signals, wherein: the control-seed value comprises a plurality of sub-values; and the one or more permutaters are adapted to reorder the sub-values of the control-seed value to generate the one or more control signals.