Fibre channel over ethernet

• US 20060251067A1
• Filed: 04/06/2006
• Published: 11/09/2006
• 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: DeSanti, Claudio, Gai, Silvano, Baldini, Andrea
• Granted Patent: US 8,238,347 B2
• Time in Patent Office: Days
• US Class Current: 370/389
• CPC Class Codes: H04L 12/462 LAN interconnection over a bridge based backbone
• CPC Class Codes: H04L 12/4633 Interconnection of networks using encapsulation techniques, e.g. tunneling
• CPC Class Codes: H04L 2101/604 Address structures or formats
• CPC Class Codes: H04L 2101/622 Layer-2 addresses, e.g. medium access control [MAC] addresses
• CPC Class Codes: H04L 2212/00 Encapsulation of packets
• CPC Class Codes: H04L 49/351 for local area network [LAN], e.g. Ethernet switches
• CPC Class Codes: H04L 49/357 Fibre channel switches

Abstract

A Data Center Ethernet (“DCE”) network and related methods and device are provided. A DCE network simplifies the connectivity of data centers and provides a high bandwidth, low latency network for carrying Ethernet, storage and other traffic. A Fibre Channel (“FC”) frame, including FC addressing information, is encapsulated in an Ethernet frame for transmission on a Data Center Ethernet (“DCE”) network. The Ethernet address fields may indicate that the frame includes an FC frame, e.g., by the use of a predetermined Organization Unique Identifier (“OUI”) code in the D_MAC field, but also include Ethernet addressing information. Accordingly, the encapsulated frames can be forwarded properly by switches in the DCE network whether or not these switches are configured for operation according to the FC protocol. Accordingly, only a subset of Ethernet switches in the DCE network needs to be FC-enabled. Only switches so configured will require an FC Domain_ID.

Claims

1. A network, comprising:

a first plurality of switches configured for operation according to the Fibre Channel (“

FC”

) protocol; and

a second plurality of switches configured for operation according to the Ethernet protocol but not configured for operation according to the FC protocol, wherein each of the first plurality of switches and each of the second plurality of switches are configured to carry traffic according to multiple protocols on virtual lanes of the same physical link.

2. The network of claim 1, wherein at least some of the traffic on the network comprises FC frames that are encapsulated as Ethernet frames.

3. The network of claim 1, wherein each switch of the first plurality of switches is assigned an FC Domain_ID and wherein each switch of the second plurality of switches is not assigned an FC Domain_ID.

4. The network of claim 1, wherein each of the second plurality of switches is configured to forward any encapsulated FC frame to a predetermined switch of the first plurality of switches.

5. The network of claim 1, wherein each virtual lane carries traffic according to a predetermined protocol.

6. The network of claim 1, wherein the multiple protocols include at least the Ethernet protocol and the FC protocol.

7. The network of claim 1, wherein the multiple protocols include a clustering protocol.

8. The network of claim 2, wherein each of the Ethernet frames has an Ethertype field that indicates the Ethernet frame encapsulates an FC frame.

9. The network of claim 2, wherein each device in the network that is configured to encapsulate an FC frame in an Ethernet frame is also configured to perform the following steps:

determine whether the Ethernet frame has a minimum size required by an Ethernet protocol; and

pad the Ethernet frame when it is determined that the Ethernet frame does not have a minimum size required by the Ethernet protocol.

10. The network of claim 4, wherein any FC frame is encapsulated in an Ethernet frame.

11. The network of claim 10, further comprising a third plurality of host devices, wherein an FC frame is formed and encapsulated in an Ethernet frame by one of a host device of third plurality of host devices or a switch of the first plurality of switches.

12. The network of claim 11, wherein the Ethernet frame comprises:

a destination media access control address (“

D_MAC”

) field having a first portion with an Organization Unique Identifier (“

OUI”

) value indicating that the DMAC address is mapping an FC D_ID and a second portion that is the mapped FC destination identification (“

D_ID”

) information corresponding to the D_ID of the encapsulated FC frame; and

a source MAC (S_MAC) field that indicates the MAC address of the device that generated the FC frame.

13. The network of claim 12, wherein the predetermined switch of the first plurality of switches is configured to perform the following steps:

receive the Ethernet frame;

determine that the Ethernet frame contains an FC frame;

decapsulate the FC frame;

either forward or locally process the decapsulated FC frame.

14. The network of claim 13, wherein the decapsulated FC frame is locally processed and wherein the processing implies a response, and wherein the predetermined switch is further configured to perform the following steps:

form an appropriate response;

encapsulate the response in an additional Ethernet frame having a D_MAC field indicating the device that sent the received frame; and

transmit the additional Ethernet frame to the device that sent the received frame.

15. The network of claim 13, wherein the determining step is based on at least one of the Ethertype value and the information in the D_MAC field.

16. The network of claim 14, wherein the predetermined switch is further configured to perform the following steps:

determine whether the additional Ethernet frame has a minimum size required by an Ethernet protocol; and

pad the additional Ethernet frame when it is determined that the additional Ethernet frame does not have a minimum size required by the Ethernet protocol.

17. A data networking method, comprising:

forming a first Fibre Channel (“

FC”

) frame; and

encapsulating the first FC frame to form a first Ethernet frame, the encapsulation step comprising;

including FC addressing information with the encapsulated FC frame;

inserting a MAC address of a first device performing the forming and encapsulating steps into a source MAC (“

S_MAC”

) field of the first Ethernet frame; and

inserting a code in an Ethertype field of the first Ethernet frame, the code indicating that the first Ethernet frame includes the first FC frame.

18. The method of claim 17, further comprising the step of determining whether the first Ethernet frame has a minimum size required by an Ethernet protocol.

19. The method of claim 17, wherein the first FC frame comprises an FLOGI request frame.

20. The method of claim 18, further comprising the step of padding the first Ethernet frame when it is determined that the first Ethernet frame does not have a minimum size required by the Ethernet protocol.

21. The method of claim 19, wherein the encapsulation step further comprises:

inserting an Organization Unique Identifier (“

OUI”

) code into a first portion of a destination media access control (“

MAC”

) field of the first Ethernet frame, the OUI code indicating that the first Ethernet frame contains FC information; and

inserting FC destination identification (“

D_ID”

) information from the first FC frame in a second portion of the destination MAC field of the first Ethernet frame.

22. The method of claim 19, further comprising:

receiving, by a first switch that is not operating according to the FC protocol, the first Ethernet frame; and

forwarding the first Ethernet frame to a predetermined second switch that is operating according to the FC protocol.

23. The method of claim 19, further comprising:

receiving, by a switch that is operating according to the FC protocol, the first Ethernet frame;

determining that the first Ethernet frame comprises an FLOGI request;

decapsulating the first Ethernet frame;

determining an address responsive to the FLOGI request;

forming an FLOGI ACCEPT frame that includes the address;

encapsulating the FLOGI ACCEPT frame as a second Ethernet frame; and

transmitting the second Ethernet frame to the first device.

24. The method of claim 23, wherein the step of encapsulating the FLOGI ACCEPT frame comprises inserting the MAC address of the first device into a D_MAC field of the second Ethernet frame.

25. The method of claim 23, further comprising:

receiving, by the first device, the second Ethernet frame;

decapsulating the second Ethernet frame;

reading the address in the FLOGI ACCEPT frame; and

using the address as an S_ID for subsequent transmissions that originate from the first device.

26. A gateway configured to enable communication between a storage network and a Data Center Ethernet (“

DCE”

) network, the DCE network comprising switches configured to carry traffic according to multiple protocols on virtual lanes of the same physical link, the gateway comprising;

means for receiving a first Fibre Channel (“

FC”

) frame from the storage network; and

means for encapsulating the first FC frame as a first Ethernet frame; and

means for transmitting the first Ethernet frame on a predetermined virtual lane of the DCE network.

27. The gateway of claim 26, further comprising:

means for receiving a second Ethernet frame comprising an encapsulated second FC frame;

means for decapsulating the second Ethernet frame; and

means for transmitting the second FC frame to the storage network.

28. A gateway configured to enable communication between a storage network and a Data Center Ethernet (“

DCE”

) network, the DCE network comprising switches configured to carry traffic according to multiple protocols on virtual lanes of the same physical link, the gateway comprising;

a plurality of Fibre Channel (“

FC”

) ports configured for communication with an FC network;

a plurality of Ethernet ports configured for communication with the DCE network; and

at least one logic device configured to perform the following steps;

receive a first FC frame from one of the plurality of FC ports;

encapsulate the first FC frame as a first Ethernet frame; and

forward the Ethernet frame to one of the plurality of Ethernet ports for transmission on a virtual lane of the DCE network, wherein the encapsulation step comprises;

inserting a MAC address of a first device performing the forming and encapsulating steps into a source MAC (“

S_MAC”

) field of the first Ethernet frame;

inserting a code in an Ethertype field of the first Ethernet frame, the code indicating that the first Ethernet frame includes the first FC frame; and

including FC addressing information with other encapsulated fields of the FC frame.

29. The gateway of claim 28, wherein at least one logic device is configured to perform the following steps:

receive a second Ethernet frame from one of the plurality of Ethernet FC ports, the second Ethernet frame encapsulating a second FC frame;

decapsulate the second Ethernet frame; and

forward the second FC frame to one of the plurality of FC ports for transmission on the storage network.

30. A network, comprising:

a first plurality of switches configured for operation according to the Fibre Channel (“

FC”

) protocol; and

a second plurality of switches configured to carry traffic according to multiple protocols on virtual lanes of the same physical link, the second plurality of switches comprising;

a first portion of switches that are FCoE switches configured to process FCoE frames, which are FC frames encapsulated in Ethernet frames; and

a second portion of switches that are not FCoE switches.

31. The network of claim 30, wherein the FCoE switches are configured as logical neighbors by E_Port to E_Port operation through MAC-in-MAC tunnels.

32. The network of claim 30, wherein the FCoE switches that are topologically in the network'"'"'s core are configured to be at logical edges of the network.

33. The network of claim 30, wherein at least some of the first portion of switches are configured to encapsulate FC frames as Ethernet frames, thereby forming FCoE frames, and further configured to decapsulate FCoE frames and extract the FC frames.

34. The network of claim 31, wherein only a MAC-in-MAC destination address is used to forward packets between logical neighbors.

35. The network of claim 32, wherein FCoE encapsulation is performed only by switches configured to be at logical edges of the network.