Ethernet extension for the data center

• US 20060101140A1
• Filed: 03/18/2005
• Published: 05/11/2006
• Est. Priority Date: 10/22/2004
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Edsall, Thomas, Bergamasco, Davide, Gai, Silvano, Bonomi, Flavio, Cafiero, Luca, Dutt, Dinesh
• Granted Patent: US 7,969,971 B2
• Time in Patent Office: Days
• US Class Current: 709/224
• CPC Class Codes: H04L 12/4633 Interconnection of networks using encapsulation techniques, e.g. tunneling
• CPC Class Codes: H04L 12/4641 Virtual LANs, VLANs, e.g. virtual private networks [VPN] LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/13 in a LAN segment, e.g. ring or bus
• CPC Class Codes: H04L 47/24 Traffic characterised by specific attributes, e.g. priority or QoS
• CPC Class Codes: H04L 47/266 Stopping or restarting the source, e.g. X-on or X-off
• CPC Class Codes: H04L 47/32 by discarding or delaying data units, e.g. packets or frames
• CPC Class Codes: H04L 47/39 Credit based
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers

Abstract

The present invention provides methods and devices for implementing a Low Latency Ethernet (“LLE”) solution, also referred to herein as a Data Center Ethernet (“DCE”) solution, which simplifies the connectivity of data centers and provides a high bandwidth, low latency network for carrying Ethernet and storage traffic. Some aspects of the invention involve transforming FC frames into a format suitable for transport on an Ethernet. Some preferred implementations of the invention implement multiple virtual lanes (“VLs”) in a single physical connection of a data center or similar network. Some VLs are “drop” VLs, with Ethernet-like behavior, and others are “no-drop” lanes with FC-like behavior. Some preferred implementations of the invention provide guaranteed bandwidth based on credits and VL. Active buffer management allows for both high reliability and low latency while using small frame buffers. Preferably, the rules for active buffer management are different for drop and no drop VLs.

Claims

1. A method for carrying more than one type of traffic on a single physical link, the method comprising:

logically partitioning traffic on a physical link into a plurality of virtual lanes;

applying a first set of rules to first traffic on a first virtual lane; and

applying a second set of rules to second traffic on a second virtual lane.

2. The method of claim 1, further comprising the step of differentiating service per virtual lane.

3. The method of claim 1, further comprising the steps of applying third through sets of rules to traffic on third through N^th virtual lanes.

4. The method of claim 1, wherein the first traffic comprises Ethernet traffic.

5. The method of claim 1, wherein the second traffic comprises storage traffic.

6. The method of claim 1, wherein the second traffic comprises Inter Process Communication traffic.

7. The method of claim 1, wherein the first set of rules causes frames to be dropped in response to latency.

8. The method of claim 1, wherein the second set of rules does not cause frames to be dropped in response to latency.

9. The method of claim 1, wherein the first set of rules causes an explicit congestion notification to be transmitted in response to latency.

10. The method of claim 1, wherein the second set of rules causes an explicit congestion notification to be transmitted in response to latency.

11. The method of claim 1, wherein the second set of rules causes frames to be dropped to avoid deadlocks.

12. The method of claim 1, wherein the first set of rules applies a probabilistic drop function in response to latency.

13. The method of claim 1, further comprising the step of implementing flow control per virtual lane by using one or more of a buffer-to-buffer crediting scheme and PAUSE frames.

14. The method of claim 2, wherein service is differentiated according to one or more of quality of service and access control.

15. The method of claim 9, wherein the explicit congestion notification is sent to one of a source device or an edge device.

16. The method of claim 9, wherein the explicit congestion notification is sent via one of a data frame or a control frame.

17. The method of claim 13, wherein the buffer-to-buffer crediting scheme comprises crediting according to one of frame size and a number of frames.

18. The method of claim 13, wherein buffer-to-buffer credits are indicated via one of a data frame or a control frame.

19. A network device, comprising:

means for logically partitioning traffic on a physical link into a plurality of virtual lanes;

means for applying a first set of rules to first traffic on a first virtual lane; and

means for applying a second set of rules to second traffic on a second virtual lane.

20. The network device of claim 19, wherein the first traffic comprises Ethernet traffic.

21. The network device of claim 19, wherein the second traffic comprises storage traffic.

22. The network device of claim 19, further comprising means for differentiating service per virtual lane.

23. The network device of claim 19, further comprising means for implementing flow control per virtual lane, the flow control comprising one or more of a buffer-to-buffer crediting scheme and the use of PAUSE frames.

24. The network device of claim 19, wherein the second traffic comprises Inter Process Communication traffic.

25. The network device of claim 23, wherein the buffer-to-buffer crediting scheme comprises crediting according to one of frame size and a number of frames.

26. The network device of claim 23, wherein buffer-to-buffer credits are indicated via one of a data frame or a control frame.

27. A method of transporting a plurality of traffic types on a single virtual link, the method comprising:

receiving a first frame on a physical link;

inspecting one or more fields of the first frame;

determining, based on the one or more fields, that first virtual lane rules should apply to the first frame; and

applying the first virtual lane rules to the first frame.

28. The method of claim 27, further comprising:

receiving a second frame on a physical link;

inspecting one or more fields of the second frame;

determining, based on the one or more fields, that second virtual lane rules should apply to the second frame; and

applying the second virtual lane rules to the second frame.

29. The method of claim 27, wherein the determining step comprises parsing explicit virtual lane identification information.

30. The method of claim 27, wherein the determining step comprises:

parsing implicit virtual lane identification information; and

mapping the implicit virtual lane identification information with a corresponding virtual lane.

31. The method of claim 27, wherein the first virtual lane rules comprise a first set of active buffer management rules and wherein the second virtual lane rules comprise a second set of active buffer management rules.

32. The method of claim 27, wherein the first virtual lane rules and the second virtual lane rules differentiate service per virtual lane.

33. A method of transporting a plurality of traffic types on a single virtual link, the method comprising:

initializing a physical link between a first switch port and a second switch port; and

determining whether the frame contains information required for establishing virtual lanes on the physical link.

34. The method of claim 33, further comprising the step of logically partitioning traffic on the physical link into a plurality of virtual lanes when it is determined that the frame contains information required for establishing virtual lanes on the physical link.

35. The method of claim 33, further comprising the step of establishing a standard Ethernet connection on the physical link when it is determined that the frame does not contain information required for establishing virtual lanes on the physical link.

36. An apparatus for transporting a plurality of traffic types on a single virtual link, the apparatus comprising:

means for initializing a physical link between a first switch port and a second switch port; and

means for determining whether the frame contains information required for establishing virtual lanes on the physical link.

37. The apparatus of claim 36, further comprising means for logically partitioning traffic on the physical link into a plurality of virtual lanes when it is determined that the frame contains information required for establishing virtual lanes on the physical link.

38. The apparatus of claim 36, further comprising means for establishing a standard Ethernet connection on the physical link when it is determined that the frame does not contain information required for establishing virtual lanes on the physical link.

39. A network device, comprising:

a plurality of ports, each port configured for communication on one of a plurality of physical links; and

a plurality of line cards, each line card configured to do the following;

logically partition traffic on a physical link into a plurality of virtual lanes;

apply a first set of rules to first traffic on a first virtual lane; and

apply a second set of rules to second traffic on a second virtual lane.