Method and system for congestion control based on optimum bandwidth allocation in a fibre channel switch

• US 20050018606A1
• Filed: 07/20/2004
• Published: 01/27/2005
• Est. Priority Date: 07/21/2003
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: QLogic Corporation (Marvell Technology Group Limited)
• Inventors: Dropps, Frank R., Papenfuss, Gary M.
• Granted Patent: US 7,512,067 B2
• Time in Patent Office: Days
• US Class Current: 370/230
• CPC Class Codes: H04L 12/10 Current supply arrangements
• CPC Class Codes: H04L 49/101 using crossbar or matrix
• CPC Class Codes: H04L 49/351 for local area network [LAN], e.g. Ethernet switches
• CPC Class Codes: H04L 49/357 Fibre channel switches
• CPC Class Codes: H04L 49/50 Overload detection or protection within a single switching element

Abstract

A method and system for optimizing bandwidth allocation in a fibre channel network having a fibre channel switch element, is provided. The switch element includes, a port control module having a receive and transmit segment, wherein the transmit segment is programmed to block frame transmission from a particular frame source port for a certain duration based on a programmable threshold value. The method includes, enabling a bandwidth limitation counter; and programming the threshold value for blocking frame transmission from a frame source port for a certain duration and during this duration, other source ports may be chosen for frame transmission. After a frame is transmitted from a source port, a tag valid blocking from the same source port is used to block frame transmission. A quality of service register is used to store the threshold value and the threshold value is programmable.

Claims

1. A method for optimizing bandwidth allocation in a fibre channel network having a fibre channel switch element, comprising:

enabling a bandwidth limitation counter; and

programming a threshold value for blocking frame transmission from a frame source port for certain duration and during this duration, other source ports may be chosen for frame transmission.

2. The method of claim 1, wherein after a frame is transmitted from a source port, a tag valid blocking from the same source port is used to block frame transmission.

3. The method of claim 1, wherein a quality of service register is used to store the threshold value.

4. The method of claim 3, wherein the threshold value is programmable.

5. A fibre channel switch element, comprising:

a port control module having a receive and transmit segment, wherein the transmit segment is programmed to block frame transmission from a particular frame source port for a certain duration based on a programmable threshold value.

6. The switch element of claim 5, wherein during the duration, the transmit segment may select another source port to transmit frames.

7. The switch element of claim 5, wherein a register is used to store the programmable threshold value.

8. The switch element of claim 5, wherein a counter value is compared to the threshold value to determine whether a particular frame source port should be blocked.

9. A system for optimizing bandwidth location in a fibre channel network having a fibre channel switch element, comprising:

a register for storing a threshold value that is compared to a counter value, which determines whether a particular frame source port should be blocked.

10. The system of claim 9, wherein based on the comparison frame transmission from a source port is blocked for a certain duration.

11. The system of claim 10, wherein during the duration when frame transmission from the source port is blocked, another source port is selected to transmit frames.