Abstract: A multistage data routing system for routing a plurality of data streams comprises a cube comprising a plurality of stages sequentially numbered n-1 through 0 and an extra stage n situated to proceed n-1 of the cube. Stages n through 0 comprise a plurality of data switching boxes. Each box includes a first input port, a second input port, a first output port, a second output port, and apparatus for selectively coupling the first input port to at least one of the output ports and the second input port to at least one of the output ports. Extra stage n and stage 0 include apparatus for selectively bypassing stage n or stage 0 or neither stage n nor stage 0. The system further comprises a plurality of links, each coupling a selected ouput port of a selected stage to a selected input port of the next adjacent downstream stage.