Computer Network Technology Corporation

Brocade Communication Systems LLC

Jason Workman

James C Wright

Gregory L Koellner

Harry V Paul

Larry Cantwell

Anthony G Tornetta

Steven G Schmidt

Jereld W Pearson

Scott Carlsen

Govindaswamy Nallur

Henry G Gonzalez

Anthony G Tometta

Jerald W Pearson

Henry Q Gonzalez

A routing module applies a plurality of routing rules simultaneously to determine routing for a Fibre Channel frame. Each rule independently determines whether the rule applies to the frame as well as a routing result for the frame. The routing result includes a port address, a zoning indicator, and a priority designation that can be used to route the frame over a virtual channel in an interswitch link. A selector chooses between the results returned by the rules. A component receives routing results specifying an ISL group and selects a physical ISL for the frame. An in-band priority determined by the content of the frame header can also be used in place of the priority designation in the routing result.

Rule based routing in a 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

Fiber channel switch

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Bensalem, PA, United States of America

Jason Workman