Efficient parallelized computation of a Benes network configuration

A method, comprising:

• in a routing controller comprising an interface and multiple processors, receiving via the interface a permutation defining requested interconnections between N input ports and N output ports of a Benes network,
• wherein the Benes network comprises multiple 2-by-2 switches, and is reducible in a plurality of nested subnetworks associated with respective nesting levels, down to irreducible subnetworks comprising a single 2-by-2 switch;
• collectively determining, by the processors, a setting of the 2-by-2 switches that implements the received permutation, including determining sub-settings for two or more subnetworks of a given nesting level in parallel;
• and
• configuring the multiple 2-by-2 switches of the Benes network in accordance with the determined setting,
• wherein determining the setting comprises alternately scanning input lines and output lines of at least a subnetwork of the Benes network, and determining states of an input switch coupled to a given input lines and of an output switch coupled to a given output line, so that the given input line and the given output line connect to a common subnetwork of a subsequent inner nesting level.