Hewlett-packard Development Company, L.P.

Compaq Computer Corporation, Inc.

Tandem Computers Incorporated

David T Heron

David Allen Brown

William P Bunton

William J Watson

Robert W Horst

David J Garcia

John C Krause

William F Bruckert

Gary R Morrison

Charles Edward Peet

James E Holeman

Robert R Teisberg

Jeffrey A Boyd

Adaptive sets of lanes are configured between routers in a system area network. Source nodes determine whether packets may be adaptively routed between the lanes by encoding adaptive control bits in the packet header. The adaptive control bits also facilitate the flushing of all lanes of the adaptive set. Adaptive sets may also be used in uplinks between levels of a fat tree.

System and method for configuring adaptive sets of links between routers in a system area network (SAN)

An improved hybrid flow control protocol for providing FIFO capacity to prevent overflow due to bytes arriving after the FIFO indicates it is not ready to receive any more bytes utilizes a combination of a high/low watermark and credit based system. In one embodiment, when the byte count exceed the high watermark fixed credits are sent when N bytes are pulled from the FIFO. In a second embodiment, variable credits are sent depending on the difference between the number of bytes received in and pulled from the FIFO.

Hybrid flow control

A data communication system embodying an apparatus and a method provides simultaneous paths between a plurality of transmit ports and a plurality of receive ports for transmitting therebetween data identifying their destination receive ports. Such data are signals which are constructed in accordance with a standard serial protocol for frame element communication, such as HDLC (High-level Data Link Control). The system is assembled in a chassis containing a backplane and multiple cards having transmit and receive ports through which the cards couple the backplane. The system includes: a receiver of data transmitted by a source transmit port, a recognizer of the destination receive port identified by the received data, a determiner of the availability of the recognized destination receive port, a connector of a path between the source transmit port and the destination receive port in response to a determination that the recognized destination receive port is available, and a transmitter of the received data to the destination receive port through the connected path.

Apparatus and method for frame switching

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Austin, TX, United States of America

David T Heron