Inventors:
Harry V. Paul - Haddonfield NJ, US
Anthony G. Tornetta - King of Prussia PA, US
Henry G. Gonzalez - Belle Mead NJ, US
Larry Cantwell - Moorestown NJ, US
Gregory L. Koellner - Medford NJ, US
Steven G. Schmidt - Westampton NJ, US
Jereld W. Pearson - Somerdale NJ, US
Jason Workman - Bensalem NJ, US
James C. Wright - Sewell NJ, US
Scott Carlsen - Mount Laurel NJ, US
Govindaswamy Nallur - Maple Shade NJ, US
Assignee:
Computer Network Technology Corporation - Minneapolis MN
International Classification:
G06F 11/00, G06F 15/173, H04L 12/54
US Classification:
370229, 370235, 370392, 370428, 709238, 709241
Abstract:
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.