Abstract: 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.

Abstract: Methods and apparatus for routing a packet in a network are described. The network has a topology characterized by a hierarchical structure of nodes including n layers. L represents a layer in the structure and is an integer with L=0 representing a lowest layer and L=n?1 representing a highest layer. The method includes receiving at least a packet header of a packet at a first node and based on the packet header, determining whether to transmit the packet to a second node in either layer L, layer L+1, or layer L?1. The packet can be transmitted to the second node as soon as the packet is received at the first node without waiting to receive the entire packet and without copying the packet prior to transmission from the first node.

Abstract: 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.