Steven J Schmidt

US Patent:

7042842, May 9, 2006

Filed:

Jun 21, 2004

Appl. No.:

10/873532

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.

US Patent:

7068651, Jun 27, 2006

Filed:

Jun 1, 2001

Appl. No.:

09/872863

Inventors:

Steven G. Schmidt - Mount Holly NJ, US
Harry V. Paul - Haddonfield NJ, US

Assignee:

Computer Network Technology Corporation - Minneapolis MN

International Classification:

H04L 12/56

US Classification:

370389, 370413, 370392, 398 57, 710 3

Abstract:

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.

US Patent:

7606150, Oct 20, 2009

Filed:

May 8, 2006

Appl. No.:

11/430132

Inventors:

Harry V. Paul - Haddonfield NJ, US
Henry Q. Gonzalez - Belle Mead NJ, US
Larry Cantwell - Morrestown NJ, US
Gregory L. Koellner - Medford NJ, US
Steven G. Schmidt - Westampton NJ, US
Jereld W. Pearson - Somerdale NJ, US
Jason Workman - Bensalem PA, 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.

US Patent:

7773622, Aug 10, 2010

Filed:

Jun 21, 2004

Appl. No.:

10/873430

Inventors:

Steven G. Schmidt - Westampton NJ, US
Anthony G. Tornetta - King of Prussia PA, US
Harry V. Paul - Haddonfield NJ, US
Henry J. Gonzalez - Belle Mead NJ, US

Assignee:

McData Services Corporation - San Jose CA

International Classification:

H04L 12/56

US Classification:

370414, 370412, 370231, 370235, 370237

Abstract:

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.

US Patent:

8379658, Feb 19, 2013

Filed:

Jun 30, 2010

Appl. No.:

12/826959

Inventors:

Steven G. Schmidt - Westampton NJ, US
Anthony G. Tornetta - King of Prussia PA, US
Harry V. Paul - Haddonfield NJ, US
Henry J. Gonzalez - Belle Mead NJ, US

Assignee:

Brocade Communications Systems, Inc. - San Jose CA

International Classification:

H04L 12/56

US Classification:

370414, 370412, 370231, 370235, 370237

Abstract:

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.

US Patent:

20030031197, Feb 13, 2003

Filed:

Aug 13, 2001

Appl. No.:

09/927359

Inventors:

Steven Schmidt - Mount Holly NJ, US

International Classification:

H04J003/02

US Classification:

370/462000, 710/240000

Abstract:

A multiple arbitration circuit capable of simultaneously arbitrating multiple paths from at least one source port to at least one destination port through a switch. The circuit comprises a crosspoint unit, and a multiple arbitration unit. The multiple arbitration unit comprises a request decoder, a prioritizer, a crosspoint select encoder and an acknowledge OR. The circuit operates such that if a source port is requesting a destination port that no other source port is requesting, then said requested destination port can be arbitrated simultaneously with requests by other source ports for other destination ports.

US Patent:

20050088969, Apr 28, 2005

Filed:

Jun 21, 2004

Appl. No.:

10/873329

Inventors:

Scott Carlsen - Mount Laurel NJ, US
Anthony Tornetta - King of Prussia PA, US
Steven Schmidt - Westampton NJ, US

International Classification:

H04L001/00
G06F011/00
G08C015/00
H04L012/28
G06F007/00
G06F017/00

US Classification:

370229000, 370389000, 709235000, 707100000

Abstract:

A congestion notification mechanism provides a congestion status for all destinations in a switch at each ingress port. Data is stored in a memory subsystem queue associated with the destination port at the ingress side of the crossbar. A cell credit manager tracks the amount of data in this memory subsystem for each destination. If the count for any destination exceeds a threshold, the credit manager sends an XOFF signal to the XOFF masks. A lookup table in the XOFF masks maintains the status for every switch destination based on the XOFF signals. An XON history register receives the XOFF signals to allow queuing procedures that do not allow a status change to XON during certain states. Flow control signals directly from the memory subsystem are allowed to flow to each XOFF mask, where they are combined with the lookup table status to provide a congestion status for every destination.

US Patent:

20060013135, Jan 19, 2006

Filed:

Jun 21, 2004

Appl. No.:

10/873330

Inventors:

Steven Schmidt - Westampton NJ, US
Harry Paul - Haddonfield NJ, US
Henry Gonzalez - Belle Mead NJ, US

International Classification:

G01R 31/08

US Classification:

370235000

Abstract:

A flow control mechanism is presented that provides XON/XOFF flow control for each virtual channel in an interswitch link. The entire interswitch link remains under standard Fibre Channel BB_Credit flow control. Each virtual channel in the interswitch link can submit data to multiple ports in the downstream switch. The XOFF status of each port in the downstream switch is maintained in an XOFF mask. A mapping between each virtual channel and all ports accessible through the virtual channel is then applied to the XOFF mask, which determines the XOFF status of each virtual channel. An XOFF signal is generated by the downstream switch on a change in XOFF status for any virtual channel. The preferred XOFF signal is one or more Fibre Channel primitive containing the status for every virtual channel. Each primitive sends duplicate XOFF information, and always ends in negative running disparity.