A network including a hierarchical structure of nodes is described. The structure of nodes includes n layers including n−1 layers of switch nodes and 1 layer of computational nodes. Each layer in the structure can include mn-L nodes grouped into units, where m represents a number of nodes in a unit and L represents a layer in the structure, where L=0 represents a lowest layer and L=n−1 represents a highest layer. Each node in a layer other than the computational layer can include a switch node for a unit in a next lower layer. For each unit, each node can be connected to each other node by a point to point link and to a local switch node for the unit by a point to point link. Each node can be connected to each other node and to the local switch node by a local broadcast network for the unit.