METHOD AND SYSTEM FOR SELECTING VIRTUAL LANES IN FIBRE CHANNEL SWITCHES

• US 20090316592A1
• Filed: 04/22/2009
• Published: 12/24/2009
• 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., Ross, Edward C., Gustafson, William J.
• Granted Patent: US 8,081,650 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04L 49/25 Routing or path finding in a switch fabric
• CPC Class Codes: H04L 49/357 Fibre channel switches

Abstract

A method for assigning virtual lanes (VL) in a fibre channel switch is provided. The fibre channel switch element includes a virtual lane cache that can compare incoming frame parameters based on which virtual lanes may be assigned; and a register to store parameters used for virtual lane assignment. The method includes, determining if VL assignment is to be based on an incoming frame parameter or a programmed value; determining if an incoming frame is a preferred frame; and assigning a preferred routing priority if the incoming frame is designated as a preferred frame. The method also includes, determining if a fabric topology is known; and assigning virtual lanes based on a known fabric topology.

Claims

1-8. -8. (canceled)

9. A method for adjusting virtual lane credit for fibre channel switches, comprising;

determining if virtual lanes are enabled with virtual lane compression; and

mapping VC_RDYs, if virtual lane compression is enabled.

10. A system for collecting virtual lane statistics in a fibre channel switch element, comprising:

plural counters for collecting information regarding a virtual lane, including a credit counter for monitoring virtual lane credit.

11. The system of claim 10, further comprising:

a counter for counting each time a frame is tossed for any hard zoning violations.

12. The system of claim 10, further comprising:

a counter for counting a number of attempts a frame makes to violate a hard zone.

13. The system of claim 10, further comprising:

a counter for counting a duration for which a frame is waiting for VL credit for transmission.

14. The system of claim 10, further comprising:

a counter for counting incoming frame and words for different frame classes.

15. The system of claim 10, further comprising:

a counter for counting an invalid transmission word at a receive segment of the fibre channel switch element.

16. The system of claim 10, further comprising:

a counter for counting CRC errors on incoming frames.

17. The system of claim 10, further comprising:

a counter for counting the number of attempts a transmit segment makes to transmit a frame but is unable to transmit the frame due to lack of virtual lane credit.

18. The system of claim 10, further comprising:

a counter for counting each time a class 3 frame is tossed from a transmit segment for violations other than hard zoning.

19. The system of claim 10, further comprising:

a counter for counting each time a class 2 and/or class 3 frame leaves a fabric.

20-27. -27. (canceled)