The document describes a butterfly network topology. A butterfly network has the following properties: - The number of nodes increases exponentially based on the number of ranks K. - The number of ranks is K+1. - The diameter of the network, the longest path between any two nodes, is 2K. - The bisection width, the number of links between the two halves of the network, is 2^K. - Nodes are connected based on their rank and identifier, with each node connecting to nodes in the previous rank based on bit inversion rules.