Method and system for routing fibre channel frames

• US 7,447,224 B2
• Filed: 07/20/2004
• Issued: 11/04/2008
• Est. Priority Date: 07/21/2003
• Status: Expired due to Fees

• 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.
• Primary Examiner(s): Pham; Chi H.
• Assistant Examiner(s): BOAKYE, ALEXANDER O
• Application Number:
  US10/894,629
• Publication Number:
  US 20050018701A1
• Time in Patent Office: 1,568 Days
• Field of Search: 370/230, 370/231, 370/235, 370/236, 370/389, 370/395, 370/400, 370/412, 370/417, 370/463, 370/474, 370/503, 370/235.1, 370/428, 370/429, 370/395.1
• US Class Current: 370/412
• CPC Class Codes: H04L 49/90 Buffering arrangements

Abstract

A method and system for transmitting frames using a fiber channel switch element is provided. The switch element includes a port having a receive segment and a transmit segment, wherein the fiber channel switch element determines if a port link has been reset; determines if a flush state has been enabled for the port; and removes frames from a buffer, if the flush state has been enabled for the port. For a flush state operation, frames are removed from a receive buffer of the fiber channel port as if it is a typical fiber channel frame transfer. The removed frames are sent to a processor for analysis. The method also includes, setting a control bit for activating frame removal from the transmit buffer; and diverting frames that are waiting in the transmit buffer and have not been able to move from the transmit buffer.

Claims

1. A method for a fibre channel switch element, comprising:

configuring a port of the fibre channel switch element to operate in a flush state;

wherein during the flush state a transmit segment of the port selectively removes a frame that is received from a source port and is temporarily stored at a received segment of the port;

establishing a disposal policy for handling frames that are removed during the flush state operation;

detecting a condition to trigger a flush state operation;

removing frames stored at the receive segment of the port, without the receive segment being aware of the flush state operation; and

disposing the frame based on the disposal policy set for handling frames that are removed during the flush state operation.

2. The method of claim 1, wherein if a removed frame is a Class 2 Fibre Channel frame, then the Class 2 frame is truncated to a minimum size before being diverted.

3. The method of claim 1, wherein the removed frame is sent to a processor that analyzes the diverted frames.

4. The method of claim 1, when a link reset is a condition that triggers the flush state operation.

5. The method of claim 1, wherein all frames from the source port are removed during the flush state operation, before frames from another source are processed.

6. The method of claim 1, wherein the disposal policy is established by setting control bits in a control port of the fibre channel switch element.

7. The method of claim 1, wherein frames removed during the flush state operation are discarded.

8. A fibre channel switch element, comprising:

a port having a receive segment and a transmit segment with a receive buffer for receiving fibre channel frames and a transmit buffer for transmitting fibre channel frames; and

logic for (a) configuring the port to operate in a flush state;

wherein during the flush state the transmit segment of the port selectively removes a frame that is received from a source port and is temporarily stored at the received segment of the port; and

(b) establishing a disposal policy for handling frames that are removed during the flush state operation;

wherein when a condition to trigger a flush state operation is detected, frames stored at the receive segment of the port are removed, without the receive segment being aware of the flush state operation; and

the removed frames are disposed based on the established disposal policy.

9. The fibre channel switch element of claim 8, wherein if a removed frame is a Class 2 Fibre Channel frame, then the Class 2 frame is truncated to a minimum size before being diverted.

10. The fibre channel switch element of claim 8, wherein the removed frame is sent to a processor that analyzes the diverted frames.

11. The switch element of claim 8, wherein a link reset is a condition that triggers the flush state operation.

12. The switch element of claim 8, wherein all frames from the source port are removed during the flush state operation, before frames from another source are processed.

13. The switch element of claim 8, wherein the disposal policy is established by setting control bit in a control port of the fibre channel switch element.

14. The switch element of claim 8, wherein frames removed during the flush state operation are discarded.

15. A method for a fibre channel switch element, comprising:

configuring a port of the fibre channel switch element to operate in a flush state;

wherein during the flush state a transmit segment of the port selectively removes a frame that is received from a source port and is temporarily stored at a received segment of the port;

establishing a disposal policy for handling frames that are removed during the flush state operation;

determining if a fibre channel switch element port link has been reset;

determining if a flush state has been enabled for the port; and

removing frames from a receive buffer of the receive segment, if the flush state has been enabled for the port;

without the receive segment being aware of the flush state operation.

16. The method of claim 15, wherein if the flush state is not enabled, then the port operates as a standard fibre channel port.

17. The method of claim 15, wherein firmware for the fibre channel switch element sets a control bit to enable flush state operation.

18. The method of claim 15, for a flush state operation, frames are removed from the receive buffer of the fibre channel port as if it is a typical fibre channel frame transfer.

19. The method of claim 15, wherein the removed frames from the receive segment are sent to a processor for analysis.

20. The method of claim 15, wherein all frames from a source port are removed during the flush state operation, before frames from another source are processed.