Computer Network Technology Corporation

Brocade Communications Systems, Inc.

Mcdata Services Corporation

Steven G Schmidt

Harry V Paul

Anthony G Tornetta

Larry Cantwell

James C Wright

Gregory L Koellner

Jereld W Pearson

Jason Workman

Scott Carlsen

Henry J Gonzalez

Govindaswamy Nallur

Henry G Gonzalez

Anthony G Tometta

William John Hughes, Iii

Henry Q Gonzalez

A method and apparatus is disclosed for temporarily deferring transmission of frames to a destination in a data switch. When a request for transmission of a frame to the destination port is received, the congestion status of that destination is determined. If the destination is congested, the frame is stored in a deferred queue. When the status of a destination changes from congested to non-congested, the deferred queue is examined to see if any deferred frames can now be forwarded to their destination. While examining the deferred queue, incoming frames are placed on a backup queue. When the deferred queue is fully analyzed, the backup queue is emptied by either sending those frames to their destination or storing the frames in the deferred queue. While examining the deferred queue, the congested states of the destinations are not allowed to change from congested to non-congested.

Deferred queuing in a buffered switch

A Fiber Channel switch is presented that tracks the congestion status of destination ports in an XOFF mask at each input. A mapping is maintained between virtual channels on an ISL and the destination ports to allow changes in the XOFF mask to trigger a primitive to an upstream port that provides virtual channel flow control. The XOFF mask is also used to avoid sending frames to a congested port. Instead, these frames are stored on a single deferred queue and later processed in a manner designed to maintain frame ordering. A routing system is provided that applies multiple routing rules in parallel to perform line speed routing. The preferred switch fabric is cell based, with techniques used to manage path maintenance for variable length frames and to adapt to varying transmission rates in the system. Finally, the switch allows data and microprocessor communication to share the same crossbar network.

Fibre channel switch

A method and apparatus for temporarily deferring transmission of packets/frames to a destination port in a buffered switch is disclosed. When a request for transmission of at least one packet/frame to the destination port is received, it is determined whether the destination port is available to receive the at least one packet/frame. The transmission of the at least one packet/frame is deferred when the destination port is not available to receive the at least one packet/frame. The packet/frame identifier and memory location for each deferred packet/frame is stored in a deferred queue and the process then repeats for the next packet/frame. Periodically, the apparatus attempts to transmit the packets/frames in the deferred queue to their respective destination ports.

A method and apparatus that recognizes a portion of an address that would be unrecognizable to an intended associated switch or device and manipulates the portion of the address to make it recognizable. The apparatus and method manipulates a discontinuous address to provide the appearance to the associated device, switch or peripheral, that the address is continuous. This provides additional address capacity such that a new address is created within the switch itself for routing data within the switch. All or a portion of the switches in network are preassigned a chassis address, and each chassis also has a specific switch address that is different from the preassigned chassis address. An address adaptor provides translation of addresses and mapping within a switch so that in the event of a port failure, affected frames can be redirected from the failed port by employing the described translation and mapping operations.

Fibre channel address adaptor having data buffer extension and address mapping in a fibre channel switch

Fiber channel switch

Growing community of inventors

Westampton, NJ, United States of America

Steven G Schmidt