Fibre channel over ethernet

• US 9,246,834 B2
• Filed: 09/15/2014
• Issued: 01/26/2016
• 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: Cafiero, Luca, Gai, Silvano
• Primary Examiner(s): Chou, Albert T
• Application Number:
  US14/486,371
• Publication Number:
  US 20150036499A1
• Time in Patent Office: 498 Days
• US Class Current: 1/1
• CPC Class Codes: H04L 12/4625 Single bridge functionality, e.g. connection of two networks over a single bridge
• CPC Class Codes: H04L 2101/622 Layer-2 addresses, e.g. medium access control [MAC] addresses
• CPC Class Codes: H04L 2101/645 Fibre channel identifiers
• CPC Class Codes: H04L 47/522 Dynamic queue service slot or variable bandwidth allocation
• CPC Class Codes: H04L 61/106 across networks, e.g. mapping telephone numbers to data network addresses

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 network device, comprising:

a plurality of Data Center Ethernet (“

DCE”

) ports, an individual DCE port in communication with another DCE port over a physical link that is configured as a plurality of virtual lanes, where each of the plurality of virtual lanes is dynamically assigned as either a drop lane or a no-drop lane with at least one virtual lane assigned as a drop lane while at least one other virtual lane is assigned as a no-drop lane; and

buffer space dynamically assigned to each virtual lane.

2. The networking device of claim 1 wherein the individual DCE port maintains a credit count for an individual virtual lane of the plurality of virtual lanes and only transmits a frame when the credit count equals or exceeds the frame length.

3. The network device of claim 1 wherein the drop lanes are managed according to a probabilistic drop function, which gradually increases the probability of dropping a packet from 0% to 100% over a period of time.

4. The network device of claim 1 wherein the network device is configured to perform a storage gateway function.

5. The network device of claim 1 wherein the network device transforms FC frames as Ethernet frames.

6. The network device of claim 1 wherein an individual virtual lane is assigned a guaranteed bandwidth on the physical link.

7. The network device of claim 6 wherein the guaranteed bandwidth is dynamically changed.

8. The network device of claim 1 wherein a virtual lane is identified in a header of a DCE frame carried by the virtual lane.

9. A method, comprising:

logically partitioning traffic by a network device on a physical link of a plurality of physical links into a plurality of virtual lanes, wherein each of the plurality of virtual lanes is dynamically assigned as a drop lane or a no-drop lane with at least one virtual lane assigned as a drop lane while at least one other virtual lane is assigned as a no-drop lane;

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

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

dynamically assigning buffer space to each virtual lane.

10. The method of claim 9, wherein the first traffic comprises Ethernet traffic.

11. The method of claim 9, wherein the second traffic comprises storage traffic.

12. The method of claim 9, wherein the first set of rules causes frames to be dropped in response to latency.

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

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

15. The method of claim 9, wherein each of the plurality of physical links corresponds to one of a plurality of Data Center Ethernet (“

DCE”

) ports.

16. The method of claim 15, wherein a header of a DCE frame carried by one of the plurality of virtual lanes comprises an identifier of the corresponding one of the plurality of lanes.