Interworking between MPLS/IP and Ethernet OAM mechanisms

1. A method comprising:

receiving, by a provider edge (PE) device, a transport layer status message indicative of a defect on a pseudowire (PW) running across a Multi-Protocol Label Switching/Internet Protocol (MPLS/IP) core of a service provider (SP) network;

identifying the defect at least in part by examining the transport layer status message;

selecting, based at least in part on the defect, a service layer message indicative of the defect, the service layer message comprising an Ethernet Operations Administration, and Maintenance (OAM) message; and

sending, by the PE device, the service layer message to a customer edge (CE) device over an Ethernet access domain of the SP network.

2. The method of claim 1 further comprising receiving, by the PE device, a Virtual Circuit Connectivity Verification (VCCV)/Bidirectional Forwarding Detection (BFD) transport layer status notification.

3. The method of claim 1 wherein the receiving of the transport layer status message comprises receiving a Label Distribution Protocol (LDP) status message from an upstream PE device, the LDP status message indicating a reverse defect.

4. The method of claim 1 wherein the receiving of the transport layer status message comprises receiving a Label Distribution Protocol (LDP) status message from an upstream PE device, the LDP status message indicating a forward defect.

5. The method of claim 1 wherein the sending of the service layer message comprises sending an Ethernet Local Management Interface (E-LMI) message on an attachment circuit of the access domain.

6. The method of claim 1 wherein the sending of the service layer message comprises sending a Connectivity Fault Management (CFM) Alarm Indication Signal (AIS) message on an attachment circuit of the access domain.

7. The method of claim 1 further comprising stopping the sending of Connectivity Fault Management (CFM) connectivity check messages on an attachment circuit of the access domain.

8. A method comprising:

detecting, by a provider edge (PE) device, a Connectivity Fault Management (CFM) Alarm Indication Signal (AIS) message on an attachment circuit of an Ethernet access domain of a Service Provider (SP) network using a native Ethernet Operations, Administration, and Maintenance (OAM) mechanism; the CFM AIS message being indicative of a local defect;

identifying the local defect at least in part by examining the CFM AIS message;

selecting, based at least in part on the local defect, a transport layer pseudowire (PW) status message indicative of the local defect, the transport layer PW status message comprising a Label Distribution Protocol (LDP) status message; and

sending, by the PE device, the LDP status message to a remote PE device over a Multi-protocol Label Switching (MPLS) control channel of the SP network.

9. The method of claim 8 wherein the sending of the LDP status message comprises sending the LDP status message with a pseudowire forwarding code to a remote PE device.

10. The method of claim 8 further comprising clearing the AIS message on the attachment circuit of the Ethernet access domain.

11. The method of claim 8 wherein the native Ethernet OAM mechanism comprises an Ethernet Connectivity Fault Management (CFM) mechanism.

12. The method of claim 8 wherein the native Ethernet OAM mechanism comprises an IEEE 802.3ah link OAM message.

13. The method of claim 8 wherein the native Ethernet OAM mechanism comprises an Ethernet Local Management Interface (E-LMI) message.

14. An apparatus comprising:

a first port to receive a Connectivity Fault Management (CFM) Alarm Indication Signal (AIS) message indicative of a fault on an attachment circuit in an Ethernet access domain of a service provider (SP) network;

a second port for connection to a Multi-Protocol Label Switching/Internet Protocol (MPLS/IP) core of the SP network; and

at least one processor operable to:

identify the fault at least in part by examining the CFM AIS message;

generate, based at least in part on the fault, a Label Distribution Protocol (LDP) pseudowire (PW) status message indicative of the fault;

send the LDP PW status message via the second port to a remote peer device responsive to receiving the CFM AIS message;

generate an Ethernet CFM Remote Defect Indicator (RDI) message responsive to a different LDP pseudowire (PW) status message indicative of a defect received at the second port; and

transmit the Ethernet CFM RDI message across the Ethernet access domain.

15. The apparatus of claim 14 wherein the LDP PW status message is sent over a PW of the MPLS core.

16. The apparatus of claim 14 wherein the at least one processor is further operable to clear the CFM AIS message on the attachment circuit.

17. An apparatus comprising:

a first port to receive a pseudowire (PW) transport layer status message transmitted over a Multi-Protocol Label Switching/Internet Protocol (MPLS/IP) core of a service provider (SP) network, the PW transport layer status message being indicative of a remote defect;

at least one processor operable to:

identify the remote defect at least in part by examining the PW transport layer status message;

generate, based at least in part on the remote defect, an Ethernet Operations, Administration, and Maintenance (OAM) service layer message; and

transmit the Ethernet OAM service layer message across an Ethernet access domain;

a second port to receive an Ethernet OAM service layer message indicative of a local defect in the Ethernet access domain of the SP network; and

wherein the at least one processor is further operable to:

identify the local defect at least in part by examining the PW Ethernet OAM service layer message;

generate, based at least in part on the local defect, a Label Distribution Protocol (LDP) status message; and

transmit the LDP status message to a remote peer over the MPLS/IP core.

18. The apparatus of claim 17 wherein the Ethernet OAM service layer message comprises an Ethernet Local Management Interface (E-LMI) message.

19. The apparatus of claim 17 wherein the Ethernet OAM service layer message comprises a Connectivity Fault Management (CFM) message.