Apparatus and method for enabling intelligent Fibre-Channel connectivity over transport

• US 7,706,294 B2
• Filed: 03/31/2003
• Issued: 04/27/2010
• Est. Priority Date: 03/31/2003
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Wang, Yanfeng, Deng, Yu, Natarajan, Sriram, Prasad, Sharat
• Primary Examiner(s): Juntima; Nittaya
• Application Number:
  US10/403,896
• Publication Number:
  US 20050074027A1
• Time in Patent Office: 2,584 Days
• Field of Search: 370/248, 370/249, 370/419, 370/252, 370/253, 370/235, 370/236, 370/242, 370/241, 370/216, 370/227, 370/228, 370/225, 370/389, 370/401, 370/465, 370/466, 709/223, 709/224, 710/306
• US Class Current: 370/252
• CPC Class Codes: H04L 12/4633 Interconnection of networks using encapsulation techniques, e.g. tunneling
• CPC Class Codes: H04L 43/00 Arrangements for monitoring or testing data switching networks
• CPC Class Codes: H04L 43/0811 by checking connectivity
• CPC Class Codes: H04L 49/357 Fibre channel switches

Abstract

The link status of a Fibre-Channel link interconnecting two Fibre-Channel ports may be determined by a third entity distinct from the two Fibre-Channel ports. The third entity may be a transport interface used to connect one of the Fibre-Channel ports to a transport network that carries the link. The transport interface may also learn the Fibre-Channel port types of the two ports.

Claims

1. A method comprising:

at a transport network interface apparatus associated with a first Fiber-Channel port that is to communicate over a transport network with a second Fiber-Channel port, monitoring link establishment frames originated by and communicated between said first Fibre-Channel port and said second Fibre-Channel port; and

at the transport network interface apparatus, based on said link establishment frames, determining said link status between said first Fibre-Channel port and said second Fibre-Channel port and port types among a plurality of possible port types of said first and second Fibre Channel ports using a state machine, wherein flow through states of the state machine depends on the link status and port types of the first Fibre-Channel port and the second Fibre-Channel port according to the link establishment frames exchanged between the first Fibre-Channel port and the second Fibre-Channel port.

2. The method of claim 1 wherein said determining comprises determining that said first Fibre-Channel port comprises an N_Port and said second Fibre-Channel port comprises an N_port.

3. The method of claim 1 wherein said determining comprises determining that said first Fibre-Channel port comprises an N_port and said second Fibre-Channel port comprises an F_port.

4. The method of claim 1 wherein said determining comprises determining that said first Fibre-Channel port comprises an E_port and said second Fibre-Channel port comprises an E_port.

5. The method of claim 1 wherein said determining comprises determining that a link establishment frame is expected from one of said first Fibre-Channel port and said second Fibre-Channel port.

6. The method of claim 1 wherein monitoring comprises monitoring link establishment frames formatted according to a protocol selected from the group consisting of Gigabit Ethernet, 2.5 Gigabit Ethernet, 10 Gigabit Ethernet, and SONET networks.

7. The method of claim 1, wherein determining comprises determining whether the link establishment frames comprise an exchange link parameter for a flow control scheme that is not supported, and further comprising blocking the exchange link parameter and generating a reject message to the first Fibre-Channel port when an unsupported flow control scheme is detected.

8. The method of claim 1, wherein determining comprises using the state machine that defines a plurality of states, including a link initialization state, a remote exchange link response state that persists until an exchange link response is received from a remote port corresponding to the second Fibre-Channel port, a local exchange link response state that persists until an exchange link response is received from a local port corresponding to the first Fibre-Channel port, a generate switch reject state, a local fabric login response state that persists until a fabric login response is received from the local port, a remote fabric login response state that persists until a fabric login response is received from the remote port, an exchange link parameter completion state that is reached from the remote local exchange link response state or remote exchange link response state, a remote/local port login state that persists until a local or remote port login frame is received, a local port login response state that persists until a local port login response is received, a remote port login state that persists until a remote port login response is received, and a login complete state upon completion of fabric login or port login, and wherein determining comprises determining transitions between the plurality of states based on detected link establishment frames.

9. An apparatus comprising:

an ingress block configured to connect to a local Fibre-Channel port and to encapsulate frames to be transmitted over a transport network to a remote Fibre-Channel port;

an egress block configured to connect to the local Fibre-Channel port and to deencapsulate frames from packets received over the transport network; and

a processor that is configured to monitor link establishment frames originated by and communicated between said local Fibre-Channel port and said remote Fibre-Channel port and, based on said link establishment frames, to determine a link status between said local Fibre-Channel port and said remote Fibre-Channel port and port types of said local Fibre-Channel port said remote Fibre-Channel port, wherein the processor is configured to determine link status and port types using a state machine, wherein flow through states of the state machine depends on the link status and the port types among a plurality of possible port types of the local Fibre-Channel port and the remote Fibre-Channel port according to the link establishment frames exchanged between the local Fibre-Channel port and the remote Fibre-Channel port.

10. The apparatus of claim 9 wherein said processor determines that said local Fibre-Channel port comprises an N_Port and said remote Fibre-Channel port comprises an N_port.

11. The apparatus of claim 9 wherein said processor determines that said local Fibre-Channel port comprises an N_port and said remote Fibre-Channel port comprises an F_port.

12. The apparatus of claim 9 wherein said processor determines that said local Fibre-Channel port comprises an E_port and said remote Fibre-Channel port comprises an E_port.

13. The apparatus of claim 9 wherein said processor determines that a link establishment frame is expected from one of said local Fibre-Channel port and said remote Fibre-Channel port.

14. The apparatus of claim 9 wherein said processor is configured to monitor link establishment frames formatted according to a protocol selected from the group consisting of Gigabit Ethernet, 2.5 Gigabit Ethernet, 10 Gigabit Ethernet, and SONET networks.

15. The apparatus of claim 9, wherein the processor is configured to determine whether the link establishment frames comprise an exchange link parameter for a flow control scheme that is not supported, and to block the exchange link parameter and generate a reject message to the first Fibre-Channel port when an unsupported flow control scheme is detected.

16. The apparatus of claim 9, wherein the processor is configured to determine link status and port types using the state machine that defines a plurality of states, including a link initialization state, a remote exchange link response state that persists until an exchange link response is received from the remote Fibre-Channel port, a local exchange link response state that persists until an exchange link response is received from the local Fibre-Channel port, a generate switch reject state, a local fabric login response state that persists until a fabric login response is received from the local Fibre-Channel port, a remote fabric login response state that persists until a fabric login response is received from the remote Fibre-Channel port, an exchange link parameter completion state that is reached from the remote local exchange link response state or remote exchange link response state, a remote/local port login state that persists until a local or remote port login frame is received, a local port login response state that persists until a local port login response is received, a remote port login state that persists until a remote port login response is received, and a login complete state upon completion of fabric login or port login, and wherein the processor is configured to determine transitions between the plurality of states based on detected link establishment frames.

17. A tangible computer readable memory storing code that, when executed by a processor, causes the processor to:

monitor link establishment frames originated by and communicated between a first Fibre-Channel port and a second Fibre-Channel port that communicate with each other over a transport network; and

based on said link establishment frames, determine link status between said first Fibre-Channel port and said second Fibre-Channel port and port types of said first Fibre-Channel port and said second Fibre-Channel port using a state machine, wherein flow through states of the state machine depends on the link status and the port types among a plurality of possible port types of the first Fibre-Channel port and the second Fibre-Channel port according to the link establishment frames exchanged between the first Fibre-Channel port and the second Fibre-Channel port.

18. The tangible computer readable memory of claim 17 wherein said code that causes the processor to determine said link status comprises code that, when executed by the processor, causes the processor to determine that a link establishment frame is expected from one of said first Fibre-Channel port and said second Fibre-Channel port.

19. The tangible computer readable memory of claim 17, wherein the code that causes the processor to determine comprises code that, when executed by the processor, causes the processor to determine whether the link establishment frames comprise an exchange link parameter for a flow control scheme that is not supported, and to block the exchange link parameter and generate a reject message to the first Fibre-Channel port when an unsupported flow control scheme is detected.

20. The tangible computer readable memory of claim 17, wherein the code that causes the processor to determine comprises code that, when executed by the processor, causes the processor to determine link status and port types using the state machine that defines a plurality of states, including a link initialization state, a remote exchange link response state that persists until an exchange link response is received from a remote port corresponding to the second Fibre-Channel port, a local exchange link response state that persists until an exchange link response is received from a local port corresponding to the first Fibre-Channel port, a generate switch reject state, a local fabric login response state that persists until a fabric login response is received from the local port, a remote fabric login response state that persists until a fabric login response is received from the remote port, an exchange link parameter completion state that is reached from the remote local exchange link response state or remote exchange link response state, a remote/local port login state that persists until a local or remote port login frame is received, a local port login response state that persists until a local port login response is received, a remote port login state that persists until a remote port login response is received, and a login complete state upon completion of fabric login or port login, and code that, when executed the processor, causes the processor to determine transitions between the plurality of states based on detected link establishment frames.