Method and system for selecting virtual lanes in fibre channel switches

• US 8,081,650 B2
• Filed: 04/22/2009
• Issued: 12/20/2011
• 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
• Primary Examiner(s): PHUNKULH, BOB A
• Application Number:
  US12/427,966
• Publication Number:
  US 20090316592A1
• Time in Patent Office: 972 Days
• Field of Search: None
• US Class Current: 370/437
• 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 fiber channel switch is provided. The fiber 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. A method for adjusting virtual lane credit for switches, the method comprising;

determining if all copies of a frame have been sent to all destinations from among a plurality of frame destinations;

determining if virtual lanes are enabled;

determining if virtual lane compression is enabled;

if virtual lane compression is enabled, mapping a plurality of virtual lane identifiers to a plurality of primitives with compression;

if virtual lane compression is not enabled, mapping the plurality of virtual lane identifiers to the plurality of primitives without compression; and

spawning the plurality of primitives.

2. The method of claim 1, wherein if it is determined that all copies of the frame have not been sent to all the destinations, determining if there is a request for the frame and status.

3. The method of claim 2, wherein if it is determined that there is a request for the frame and the status, determining if virtual lane compression is enabled, and, if it is, mapping the plurality of virtual lane identifiers to a virtual lane credit management mechanism with compression.

4. The method of claim 3, further comprising sending the status to a transmit arbiter and the frame to a transmit buffer.

5. The method of claim 2, wherein if it is determined that there is a request for the frame and the status, determining if virtual lane compression is enabled, and, if it is not, mapping the plurality of virtual lane identifiers to a virtual lane credit management mechanism without compression.

6. The method of claim 5, further comprising sending the status to a transmit arbiter and the frame to a transmit buffer.