Method for establishing multi segment pseudowire across domains having different pseudowire signaling protocol

1. A method of establishing a multi-segment pseudowire (MS-PW) across two domains, the two domains being coupled by an edge device, the method including the step of:

forwarding a label mapping message to a first edge device coupled to a first domain of the two domains using a first pseudowire signaling protocol, the label mapping message including an MS-PW element including fields associated with a second pseudowire signaling protocol.

2. The method according to claim 1 , wherein the first domain of the two domains establishes pseudowires using the first pseudowire signaling protocol, and wherein a second domain of the two domains establishes pseudowires using the second pseudowire signaling protocol.

3. The method according to claim 2 , wherein the second domain is coupled by a second edge device, further comprising a third domain coupled to the second edge device, wherein at least one of the first domain, the second domain and the third domain uses a pseudowire signaling protocol that is different from at least one of the first domain and the second domain.

4. The method according to claim 1 , wherein at least one of the first pseudowire signaling protocol and the second pseudowire signaling protocol is a Label distribution Protocol.

5. The method according to claim 4 , wherein the label mapping message includes a Forwarding Equivalency Class (FEC) pseudowire identifier (PWid) element, and wherein a MS-PW Type-Length-Value (TLV) element includes at least one of FEC Generalized PWid information, Layer 2 Tunneling Protocol (L2TP) information and Resource Reservation Protocol-Traffic Engineering (RSVP-TE) information.

6. The method according to claim 5 , wherein the label mapping message includes a Forwarding Equivalency Class (FEC) Generalized pseudowire ID (PWid) element, and wherein the MS-PW TLV element includes at least one of FEC PWid element information, the Layer 2 Tunneling Protocol (L2TP) information and the Resource Reservation Protocol-Traffic Engineering (RSVP-TE) information.

7. The method according to claim 4 , wherein the label mapping message includes a Forwarding Equivalency Class (FEC) pseudowire identifier (PWid) element, and wherein a Source Attachment Individual Identifier (SAII) of a MS-PW Type-Length-Value (TLV) element is equal to a PWID value of the FEC PWid element.

8. The method according to claim 1 wherein the MS-PW element includes Attachment Information.

9. The method according to claim 8 wherein the Attachment Information includes at least one of an Attachment Group Identifier, a Source Attachment Individual Identifier and a Target Attachment Individual Identifier (TAII).

10. The method according to claim 9 , wherein the first domain of the two domains uses a Forwarding Equivalency Class (FEC) pseudowire identifier (PWid) signaling protocol, and wherein the TAII of the MS-PW element is equal to a PWID field in the FEC PWid.

11. The method according to claim 1 wherein the MS-PW element includes pseudowire signaling protocol information from a third domain.

12. A method of establishing a multi-segment pseudowire includes the steps of:

receiving an upstream label message from an upstream edge device using a first pseudowire signaling protocol, the upstream label message including a Forwarding Equivalency Class (FEC) element including information associated with the first pseudowire signaling protocol and a multi-segment pseudowire (MS-PW) element including information associated with a second pseudowire signaling protocol;

determining that a downstream edge device uses the second pseudowire signaling protocol; and

modifying the upstream label message to provide a downstream label message, including the step of extracting information from the MS-PW element to include in a downstream FEC element of the downstream label message; and

forwarding the downstream label message to the downstream edge device.

13. An edge device comprising:

a label map for associating labels with pseudowires;

label modification logic, coupled to the label map, for generating a label mapping message including a Forwarding Equivalency Class (FEC) element for storing information related to a first pseudowire signaling protocol and a multi-segment pseudowire (MS-PW) element for storing information related to a second pseudowire signaling protocol; and

forwarding logic for forwarding the label mapping message to a domain-coupled edge device.

14. The edge device of claim 13 disposed between a first domain and a second domain of a packet switched network (PSN), wherein the first domain establishes pseudowires using the first pseudowire signaling protocol, and wherein the second domain establishes pseudowires using the second pseudowire signaling protocol.

15. The edge device according to claim 14 wherein the MS-PW element includes pseudowire signaling protocol information from a third domain.

16. The edge device of claim 13 , wherein at least one of the first pseudowire signaling protocol and the second pseudowire signaling protocol is a Label distribution Protocol.

17. The edge device according to claim 16 , wherein the label mapping message includes a Forwarding Equivalency Class (FEC) pseudowire ID (PWid) element, and wherein a MS-PW Type-Length-Value (TLV) element includes at least one of FEC Generalized PWid information, Layer 2 Tunneling Protocol (L2TP) information and Resource Reservation Protocol-Traffic Engineering (RSVP-TE) information.

18. The edge device according to claim 17 , wherein the label mapping message includes a Forwarding Equivalency Class (FEC) Generalized pseudowire ID (PWid) element, and wherein the MS-PW TLV element includes at least one of FEC PWid element information, Layer 2 Tunneling Protocol (L2TP) information and Resource Reservation Protocol-Traffic Engineering (RSVP-TE) information.

19. The edge device according to claim 13 wherein the MS-PW element includes Attachment Information.

20. The edge device according to claim 19 wherein the Attachment Information includes at least one of an Attachment Group Identifier, a Source Attachment Individual Identifier and a Target Attachment Individual Identifier (TAII).

21. The edge device according to claim 20 , wherein a first domain uses an FEC pseudowire identifier (PWid) signaling protocol, and wherein the TAII of the MS-PW element is equal to a PWID field in the FEC PWid.

22. The edge device according to claim 13 , wherein the label mapping message includes a Forwarding Equivalency Class (FEC) pseudowire ID (PWid) element, and wherein a Source Attachment Individual Identifier (SAII) of a MS-PW Type-Length-Value (TLV) element is equal to a PWID value of the FEC PWid element.

23. The edge device according to claim 13 , wherein the label modification logic includes:

receiving logic, for receiving an upstream label mapping message from an upstream edge device;

logic for determining that a downstream edge device uses the second pseudowire signaling protocol; and

logic for extracting information from a multi-segment pseudowire (MS-PW) element to generate a downstream label mapping message for the downstream edge device in the second pseudowire signaling protocol.

24. A non-transitory computer readable medium storing a label map for associating labels with pseudowires and instructions comprising:

a step for generating a label message comprising a label Type-Length-Value (TLV), a Forwarding Equivalency Class (FEC) TLV element for storing information related to a first pseudowire signaling protocol and a multi-segment pseudowire (MS-PW) TLV element for storing information related to a second pseudowire signaling protocol; and

a step for forwarding the label message to a domain-coupled edge device.