Methods and apparatus for trunking in fibre channel arbitrated loop systems

• US 20040085972A1
• Filed: 07/10/2003
• Published: 05/06/2004
• Est. Priority Date: 07/02/2002
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Vixel Corporation (Broadcom, Inc.)
• Inventors: White, Michael L., Warren, Bruce Gregory, Goodwin, William, Mies, Carl, Hammond-Doel, Thomas
• Granted Patent: US 7,630,300 B2
• Time in Patent Office: Days
• US Class Current: 370/401
• CPC Class Codes: H04L 12/433 with asynchronous transmission, e.g. token ring, register insertion
• CPC Class Codes: H04L 41/0681 Configuration of triggering conditions
• CPC Class Codes: H04L 43/0817 by checking functioning
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/245 Link aggregation, e.g. trunking
• CPC Class Codes: H04L 45/28 using route fault recovery
• CPC Class Codes: H04L 45/60 Router architectures
• CPC Class Codes: H04L 47/122 by diverting traffic away from congested entities
• CPC Class Codes: H04L 49/357 Fibre channel switches
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

Methods and apparatus for switching Fibre Channel Arbitrated Loop Systems is provided between a plurality of Fibre Channel Loop devices. In one aspect of the invention, the system switches based at least in part on arbitrated loop primitives. An exemplary interconnect system may include a first port and a second port, both including port logic to monitor certain arbitrated loop primitives, a connectivity apparatus, a route determination apparatus including a routing table consisting of ALPA addresses and their associated ports, the route determination apparatus coupled to each port and the connectivity apparatus, where the connectivity apparatus creates paths between the ports based on arbitrated loop primitives. In one embodiment, the connectivity apparatus is a crossbar switch. Examples of the arbitrated loop primitives that cause the switch to create paths between ports includes one or more of the following: ARB, OPN and CLS. In yet other aspects, the system ensures device access fairness through one or more techniques, including a rotating priority system, a counter to count the number of OPNs, especially sequential OPNs, and/or priority based on port type. Device zoning may be implemented. In one implementation, the system includes trunking such that frames may be transferred on multiple ports.

Claims

1. A system for interconnecting Fibre Channel Arbitrated Loop devices comprising:

a first Fibre Channel Arbitrated loop switch,

a second Fibre Channel Arbitrated loop switch,

said first and second Fibre Channel Arbitrated Loop Switches including port logic, connectivity apparatus and route determination logic,

the route determination logic creating routes based on the receipt of certain arbitrated Loop primitives,

whereby Said first and second loop switches are interconnected by multiple interswitch links and transfer frames on both ports.

2. The system for interconnecting Fibre Channel Arbitrated Loop devices of claim 1 wherein a first group of devices make connection through a first interswitch link and a second group of devices make connection through a second, different interswitch link.

3. The system for interconnecting Fibre Channel Arbitrated Loop devices of claim 1 further including a trunk grouping table.

4. The system for interconnecting Fibre Channel Arbitrated Loop devices of claim 3 wherein the table is in the router.

5. The system for interconnecting Fibre Channel Arbitrated Loop devices of claim 3 wherein the trunk grouping table automatically learns the grouping.

6. The system for interconnecting Fibre Channel Arbitrated Loop devices of claim 5 wherein the table learns the grouping from the previous OPN from a Fibre Channel Arbitrated Loop device initiator.

7. The system for interconnecting Fibre Channel Arbitrated Loop devices of claim 6 wherein the device initiator is a SCSI initiator.

8. The system for interconnecting Fibre Channel Arbitrated Loop devices of claim 7 wherein the SCSI initiator is a server.

9. The system for interconnecting Fibre Channel Arbitrated Loop devices of claim 3 wherein the trunk grouping table contains information on SCSI initiators.

10. The system for interconnecting Fibre Channel Arbitrated Loop devices of claim 3 wherein the trunk grouping table identifies a primary port to route frames for an initiator Arbitrated Loop device.

11. The system for interconnecting Fibre Channel Arbitrated Loop devices of claim 3 wherein the trunk grouping table identifies a backup or duplicate port to route frames for an initiator Arbitrated Loop device.

12. The system for interconnecting Fibre Channel Arbitrated Loop devices of claim 3 wherein the trunk grouping table identifies a duplicate port for a device.

13. The system for interconnecting Fibre Channel Arbitrated Loop devices of claim 3 wherein the trunk grouping table identifies an initiator ALPA.

14. The system for interconnecting Fibre Channel Arbitrated Loop devices of claim 12 wherein the duplicate port is used as a failover port.

15. The system for interconnecting Fibre Channel Arbitrated Loop devices of claim 3 wherein the information about the SCSI initiators includes one or more of the following:

ALPA address for the initiator, assigned primary trunk group to route the frames, duplicate port to route the frames incase of an error with the primary trunk group.