ETHERNET FORWARDING IN HIGH PERFORMANCE FABRICS

• US 20080181243A1
• Filed: 12/17/2007
• Published: 07/31/2008
• Est. Priority Date: 12/15/2006
• Status: Abandoned Application

• Current Assignee: Brocade Communications Systems, Inc. (Broadcom, Inc.)
• Original Assignee: Brocade Communications Systems, Inc. (Broadcom, Inc.)
• Inventors: Vobbilisetty, Suresh, Arumilli, Subbarao
• Application Number:
  US11/958,325
• Publication Number:
  US 20080181243A1
• Time in Patent Office: Days
• US Class Current: 370/406
• 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 45/20 Hop count for routing purposes, e.g. TTL
• CPC Class Codes: H04L 45/24 Multipath
• CPC Class Codes: H04L 49/351 for local area network [LAN], e.g. Ethernet switches
• CPC Class Codes: H04L 49/70 Virtual switches

Abstract

As switching device forwards frames through a fabric using high performance routing protocols without requiring changes in receiving and transmitting Ethernet end stations communicating through the fabric. Each frame received by an edge point of a high performance fabric is modified to support a high performance routing protocol while the frame is within the fabric and is restored to its original format when leaving the fabric. Within the fabric, virtual L2 addressing, assigned and maintained by the fabric, is applied to the frame to accommodate the high performance routing.

Claims

1. A method of forwarding an Ethernet frame through a fabric that supports multi-path routing, wherein the Ethernet frame has addressing that includes a physical L2 source address of a source end station and a physical L2 destination address of a destination end station, the method comprising:

determining a virtual L2 destination address for the Ethernet frame, wherein the virtual L2 destination address includes information used for multi-path routing the frame to the destination end station;

modifying the addressing of the Ethernet frame to include the determined virtual L2 destination address;

forwarding the modified Ethernet frame through the fabric to the destination end station using a multi-path routing protocol based on the addressing of the modified Ethernet frame.

2. The method of claim 1 wherein the virtual L2 destination address identifies a domain identifier of an edge switch receiving the Ethernet frame from the source end station.

3. The method of claim 1 wherein the virtual L2 destination address identifies a port identifier of a port of an edge switch receiving the Ethernet frame from the source end station.

4. The method of claim 1 wherein the virtual L2 destination address identifies a time-to-live value associated with the modified Ethernet frame.

5. The method of claim 1 wherein the determining operation comprises:

determining the virtual L2 destination address based the physical L2 destination address of the destination end station.

6. The method of claim 1 further comprising:

determining a virtual L2 source address based on a port of an ingress edge switch through which the Ethernet frame is received from the source end station.

7. The method of claim 6 wherein the modifying operation comprises:

encapsulating the Ethernet frame in a frame shell having the virtual L2 destination address as a destination address of the encapsulated frame and the virtual L2 source address as a source address of the encapsulated frame.

8. The method of claim 1 wherein the modifying operation comprises:

replacing the physical L2 destination address with the virtual L2 destination address in the Ethernet frame.

9. A switching device for forwarding an Ethernet frame through a fabric that supports multi-path routing, wherein the Ethernet frame has addressing that includes a physical L2 source address of a source end station and a physical L2 destination address of a destination end station, the switching device comprising:

an address translation module that determines determining a virtual L2 destination address for the Ethernet frame, wherein the virtual L2 destination address includes information used for multi-path routing the Ethernet frame to the destination end station;

a frame translation module that modifies the addressing of the Ethernet frame to include the determined virtual L2 destination address;

a transmission module that forwards the modified Ethernet frame through the fabric to the destination end station using a multi-path routing protocol based on the addressing of the modified Ethernet frame.

10. The switching device of claim 9 wherein the virtual L2 destination address identifies a domain identifier of an edge switch receiving the Ethernet frame from the source end station.

11. The switching device of claim 9 wherein the virtual L2 destination address identifies a port identifier of a port of an edge switch receiving the Ethernet frame from the source end station.

12. The switching device of claim 9 wherein the virtual L2 destination address identifies a time-to-live value associated with the modified Ethernet frame.

13. The switching device of claim 9 wherein the address translation module determines the virtual L2 destination address based the physical L2 destination address of the destination end station.

14. The switching device of claim 9 wherein the address translation module further determines a virtual L2 source address based on a port of an ingress edge switch through which the Ethernet frame is received from the source end station.

15. The switching device of claim 14 wherein the frame translation module encapsulates the Ethernet frame in a frame shell having the virtual L2 destination address as a destination address of the encapsulated Ethernet frame and the virtual L2 source address as a source address of the encapsulated Ethernet frame.

16. The switching device of claim 9 wherein the frame translation module replaces the physical L2 destination address with the virtual L2 destination address in the Ethernet frame.

17. A method of forwarding an Ethernet frame through a fabric that supports multi-path routing, wherein the Ethernet frame has addressing that includes a physical L2 source address of a source end station and a physical L2 destination address of a destination end station, the method comprising:

determining a virtual L2 destination address for the Ethernet frame, wherein the virtual L2 destination address includes information used for multi-path routing the frame to the destination end station;

modifying the addressing of the Ethernet frame to include the determined virtual L2 destination address, the determined virtual L2 destination address including a domain identifier of an edge switch receiving the Ethernet frame from the source end station and a port identifier of a port of an edge switch receiving the Ethernet frame from the source end station;

forwarding the modified Ethernet frame through the fabric to the destination end station using a multi-path routing protocol based on the addressing of the modified Ethernet frame.

18. The method of claim 17 further comprising:

determining a virtual L2 source address based on a port of an ingress edge switch through which the Ethernet frame is received from the source end station.

19. The method of claim 18 wherein the modifying operation comprises:

encapsulating the Ethernet frame in a frame shell having the virtual L2 destination address as a destination address of the encapsulated frame and the virtual L2 source address as a source address of the encapsulated frame.

20. The method of claim 17 wherein the modifying operation comprises:

replacing the physical L2 destination address with the virtual L2 destination address in the Ethernet frame.