Abstract: A multi-nodal data processing system includes a plurality of processing nodes, each node connected to plural other nodes by bidirectional data links. Each node comprises receivers for receiving messages on bidirectional data links and transmitters for transmitting messages on bidirectional data links. Each node records child nodes to which a message was transmitted and is further adapted to transmit a lock-up message received from a child node to a parent node, the lock-up message indicating a successful establishment of a message signal path to a destination node. Each node further is adapted to transmit a link cancel signal to another node to close the link in the event of an unsuccessful message transfer attempt over the link. Each node inhibits transmission of a lock-up signal to a parent node until link cancel signals have been received from all child nodes (other than a node from which a lock-up signal was received).

Abstract: A distributed data processing system includes a plurality of nodes interconnected by bidirectional communication links. Each node includes a control message line for handling of control messages and a control memory for storing the control messages. Each node further includes data message line for handling of data messages and a data memory for storing the data messages. A processor in the node causes the data message line to queue and dispatch data messages from the data memory and the control message line to queue and dispatch control messages from the control memory. Each node includes N bidirectional communication links enabling the node to have at least twice as much input/output bandwidth as the control message line and data message line, combined. An input/output switch includes a routing processor and is coupled between the N bidirectional communication links, the data message line and control message line.