Dynamic configuration of cross-domain pseudowires

• US 8,422,514 B1
• Filed: 04/07/2010
• Issued: 04/16/2013
• Est. Priority Date: 02/09/2010
• Status: Active Grant

• Current Assignee: Juniper Networks Incorporated
• Original Assignee: Juniper Networks Incorporated
• Inventors: Kothari, Bhupesh, Sheth, Nischal
• Primary Examiner(s): Ho, Chuong T
• Application Number:
  US12/755,990
• Time in Patent Office: 1,105 Days
• Field of Search: 370/466, 370/467, 370/389, 370/401, 370351-356
• US Class Current: 370/466
• CPC Class Codes: H04L 12/4633 Interconnection of networks using encapsulation techniques, e.g. tunneling

Abstract

In general, techniques are described for dynamically configuring cross-domain pseudowires (PWs). A network device positioned between a first domain and a second domain of a computer network may implement the techniques. The intermediate network device comprises at least one interface and an LDP module, a transformation module and a routing protocol module. The interface receives a label distribution protocol (LDP) message that includes data for configuring a cross-domain PW from a first provider edge (PE) device of the first domain. The LDP module parses the received LDP message to extract the cross-domain PW configuration data. The translation module transforms the extracted data to conform to routing protocol extensions for advertising the cross-domain PW configuration data. The routing protocol module forms a routing protocol message that includes the transformed data. The interface outputs the routing protocol message to the second intermediate device of the second domain to establish the cross-domain PW.

Claims

1. A method comprising:

receiving, with a first border router, a label distribution protocol (LDP) message from a first provider edge device in accordance with the label distribution protocol (LDP), the first border router is positioned between a first domain and a second domain of a computer network and in communication with a second border router of the second domain, wherein the first provider edge device is located at an edge of the first domain of the computer network, and wherein the LDP message includes data for configuring a cross-domain pseudowire (PW) as a multi-segment pseudowire (MS-PW);

parsing, with the first intermediate device, the received LDP message to extract the data for configuring the cross-domain PW;

transforming, with the first intermediate device, the extracted data to conform to a format defined by a routing protocol different from the LDP that includes extensions for advertising the cross-domain PW configuration data;

forming, with the first intermediate device, a routing protocol message that includes the transformed data;

outputting, with the first intermediate device, the routing protocol message to the second intermediate device to establish the cross-domain PW from the first provider edge device to a second provider edge device located at an edge of the second domain of the computer network to span the first domain and the second domain;

receiving an encapsulated layer 2 (L2) data unit from the second border router, wherein the encapsulated L2 data unit comprises a header specifying a label stack containing a first label reserved by the first border router for use by a first segment of the MS-PW and a L2 data unit, and wherein the first segment of the MS-PW comprises a first pseudowire (PW) between the first and second border routers;

removing the label from the label stack of the header of the encapsulated L2 data unit;

pushing a second label reserved by the first provider edge device for use by a second segment of the MS-PW onto the label stack of the header of the encapsulated L2 data unit, wherein the second segment of the MS-PW comprises a second PW between the first provider edge device and the first border router; and

after pushing the second label onto the label stack, forwarding the encapsulated L2 data unit to the first provider edge device for delivery to a customer network.

2. The method of claim 1, wherein the routing protocol that includes extensions for advertising cross-domain PW configuration data comprises the BGP routing protocol that includes network layer reachability information (NLRI) fields defined to carry the data for configuring the cross-domain PW.

3. The method of claim 1, wherein receiving a LDP message comprises receiving a LDP message from a first provider edge device that does not implement extensions to the routing protocol that store the data for configuring the cross-domain PW.

4. The method of claim 1,

wherein the LDP message includes a forwarding equivalence class-128 (FEC-128) element that stores the data for configuring the cross-domain PW,

wherein the FEC-128 element includes a group identifier field that stores group identifier data defining a group identifier and a pseudowire (PW) identifier field that stores PW identifier data defining a PW identifier,

wherein parsing the received LDP message includes parsing the LDP message to extract the group identifier data and the PW identifier data from the FEC-128 element of the LDP message,

wherein transforming the extracted data comprises transforming the group identifier data and the PW identifier data to conform to one or more extensible fields of the routing protocol, and

wherein forming the routing protocol message includes forming the routing protocol message to include the one or more extensible fields to contain the group identifier data and PW identifier data extracted from the LDP message.

5. The method of claim 1,

wherein the LDP message includes a forwarding equivalence class-128 (FEC-128) element that stores the data for configuring the cross-domain PW,

wherein the FEC-128 element includes a group identifier field that stores group identifier data defining a group identifier, a pseudowire (PW) identifier field that stores PW identifier data defining a PW identifier and a provider edge (PE) device address field that stores PE address data defining a PE address assigned to the first provider edge device,

wherein parsing the received LDP message includes parsing the LDP message to extract the group identifier data, the PW identifier data and the PE address data from the FEC-128 element of the LDP message,

wherein transforming the extracted data comprises transforming the group identifier data, the PW identifier data and the PE address data to conform to one or more extensible fields of the routing protocol, and

wherein forming the routing protocol message includes forming the routing protocol message to include the one or more extensible fields to contain the group identifier data, the PW identifier data and the PE address data extracted from the LDP message.

6. The method of claim 5,

wherein the FEC-128 element further includes a nexthop field that stores nexthop data,

wherein parsing the received LDP message further includes parsing the LDP message to extract nexthop data,

wherein transforming the extracted data further includes transforming the nexthop data to conform to the one or more extensible fields of the routing protocol, and

wherein forming the routing protocol message further includes forming the routing protocol message to include the one or more extensible fields that contain nexthop data extracted from the LDP message.

7. The method of claim 1,

wherein the LDP message includes a forwarding equivalence class-129 (FEC-129) element that stores the data for configuring the cross-domain PW,

wherein the FEC-129 element includes an attachment group identifier (AGI) field that stores AGI data defining an AGI, a target attachment individual identifier (TAII) value field that stores TAII data defining a TAII value and a source attachment individual identifier (SAII) value field that stores SAII data defining a SAII value,

wherein parsing the received LDP message includes parsing the LDP message to extract the AGI, SAII and TAII data from the FEC-129 element of the LDP message,

wherein transforming the extracted data comprises transforming the AGI, TAII and SAII data to conform to one or more extensible fields of the routing protocol, and

wherein forming the routing protocol message includes forming the routing protocol message to include the one or more extensible fields to contain the AGI data, the TAII data and the SAII data.

8. The method of claim 7,

wherein the FEC-129 element further includes a nexthop field that stores nexthop data,

wherein parsing the received LDP message further includes parsing the LDP message to extract nexthop data,

wherein transforming the extracted data further includes transforming the nexthop data to conform to the one or more extensible fields of the routing protocol, and

wherein forming the routing protocol message further includes forming the routing protocol message to include the one or more extensible fields that contain nexthop data extracted from the LDP message.

9. The method of claim 1,

further comprising:

parsing a label from the received LDP message that the first provider edge device is assigned to the first segment of the MS-PW;

updating one or more entries within at least one label table to associate the parsed label with the first segment of the MS-PW; and

reserving a label in a label space maintained by the first network device for use by the second segment of the MS-PW,

wherein forming a routing protocol message includes forming the routing protocol message to signal the label reserved for use by the second segment of the MS-PW.

10. The method of claim 9, further comprising updating the one or more entries of the at least one label table to stitch the first segment of the MS-PW to the second segment of the MS-PW.

11. The method of claim 1,

wherein the LDP message includes a forwarding equivalence class (FEC) element comprising a PWid field that defines a type of the FEC element, and

wherein parsing the received LDP message comprises:

parsing the LDP message to extract data stored to the PWid field;

determining the type of the FEC element based on the extracted data stored to the PWid field; and

parsing the FEC element based on the determined type.

12. The method of claim 1, wherein each of the first and second provider edge devices comprise one of a router, a digital subscriber line access multiplexor (DSLAM), a cable modem termination system (CMTS), and a switch.

13. A first border router positioned between a first domain and a second domain of a computer network and in communication with a second border router of the second domain, the first border router comprising:

at least one interface that receives a label distribution protocol (LDP) message from a first provider edge device in accordance with a label distribution protocol (LDP), wherein the first provider edge device is located at an edge of the first domain of the computer network, and wherein the LDP message includes data for configuring a cross-domain pseudowire (PW) as a multi-segment pseudowire (MS-PW);

a control unit that includes;

an LDP module that parses the received LDP message to extract the data for configuring the cross-domain PW;

a translation module that transforms the extracted data to conform to a format defined by a routing protocol different from the LDP that includes extensions for advertising the cross-domain PW configuration data; and

a routing protocol module that forms a routing protocol message that includes the transformed data,

wherein the at least one interface outputs the routing protocol message to the second intermediate device to establish the cross-domain PW from the first provider edge device to a second provider edge device located at an edge of the second domain of the computer network to span the first domain and the second domain,

wherein the at least one interface receives an encapsulated layer 2 (L2) data unit from the second border router, wherein the encapsulated L2 data unit comprises a header specifying a label stack containing a first label reserved by the first border router for use by a first segment of the MS-PW and a L2 data unit, and

wherein the first segment of the MS-PW comprises a first pseudowire (PW) between the first and second border routers;

wherein the LDP module removes the label from the label stack of the header of the encapsulated L2 data unit, pushes a second label reserved by the first provider edge device for use by a second segment of the MS-PW onto the label stack of the header of the encapsulated L2 data unit, wherein the second segment of the MS-PW comprises a second PW between the first provider edge device and the first border router, and

wherein, after pushing the second label onto the label stack, the at least one interface forwards the encapsulated L2 data unit to the first provider edge device for delivery to a customer network.

14. The first border router of claim 13, wherein the routing protocol that includes extensions for advertising cross-domain PW configuration data comprises the BGP routing protocol that includes network layer reachability information (NLRI) fields defined to carry the data for configuring the cross-domain PW.

15. The first border router of claim 13, wherein the at least one interface receives an LDP message from a first provider edge device that does not implement extensions to the routing protocol that store the data for configuring the cross-domain PW.

16. The first border router of claim 13,

wherein the LDP message includes a forwarding equivalence class-128 (FEC-128) element that stores the data for configuring the cross-domain PW,

wherein the FEC-128 element includes a group identifier field that stores group identifier data defining a group identifier and a pseudowire (PW) identifier field that stores PW identifier data defining a PW identifier,

wherein the LDP module parses the LDP message to extract the group identifier data and the PW identifier data from the FEC-128 element of the LDP message,

wherein the translation module transforms the group identifier data and the PW identifier data to conform to one or more extensible fields of the routing protocol, and

wherein the routing protocol module forms the routing protocol message to include the one or more extensible fields to contain the group identifier data and PW identifier data extracted from the LDP message.

17. The first border router of claim 13,

wherein the LDP message includes a forwarding equivalence class-128 (FEC-128) element that stores the data for configuring the cross-domain PW,

wherein the FEC-128 element includes a group identifier field that stores group identifier data defining a group identifier, a pseudowire (PW) identifier field that stores PW identifier data defining a PW identifier and a provider edge (PE) device address field that stores PE address data defining a PE address assigned to the first provider edge device,

wherein the LDP module parses the LDP message to extract the group identifier data, the PW identifier data and the PE address data from the FEC-128 element of the LDP message,

wherein the translation module transforms the group identifier data, the PW identifier data and the PE address data to conform to one or more extensible fields of the routing protocol, and

wherein the routing protocol module forms the routing protocol message to include the one or more extensible fields to contain the group identifier data, the PW identifier data and the PE address data extracted from the LDP message.

18. The first border router of claim 17,

wherein the FEC-128 element further includes a nexthop field that stores nexthop data,

wherein the LDP module parses the LDP message to extract nexthop data,

wherein the translation module transforms the nexthop data to conform to the one or more extensible fields of the routing protocol, and

wherein the routing protocol module forms the routing protocol message to include the one or more extensible fields that contain nexthop data extracted from the LDP message.

19. The first border router of claim 13,

wherein the LDP message includes a forwarding equivalence class-129 (FEC-129) element that stores the data for configuring the cross-domain PW,

wherein the FEC-129 element includes an attachment group identifier (AGI) field that stores AGI data defining an AGI, a target attachment individual identifier (TAII) value field that stores TAII data defining a TAII value and a source attachment individual identifier (SAII) value field that stores SAII data defining a SAII value,

wherein the LDP module parses the LDP message to extract the AGI, SAII and TAII data from the FEC-129 element of the LDP message,

wherein the translation module transforms the AGI, TAII and SAII data to conform to one or more extensible fields of the routing protocol, and

wherein the routing protocol module forms the routing protocol message to include the one or more extensible fields to contain the AGI data, the TAII data and the SAII data.

20. The first border router of claim 19,

wherein the FEC-129 element further includes a nexthop field that stores nexthop data,

wherein the LDP module parses the LDP message to extract nexthop data,

wherein the translation module transforms the nexthop data to conform to the one or more extensible fields of the routing protocol, and

wherein the routing protocol module forms the routing protocol message to include the one or more extensible fields that contain nexthop data extracted from the LDP message.

21. The first border router of claim 13,

wherein the LDP module parses a label from the received LDP message that the first provider edge device assigned to a first LDP segment of the MS-PW, updates one or more entries within at least one label table to associate the parsed label with the first LDP segment of the MS-PW and reserves a label in a label space maintained by the first network device for use by a second routing protocol segment of the MS-PW, and

wherein the routing protocol module forms the routing protocol message to signal the label reserved for use by the second routing protocol segment of the MS-PW.

22. The first border router of claim 21, wherein the LDP module updates the one or more entries of the at least one label table to stitch the first LDP segment of the MS-PW to the second routing protocol segment of the MS-PW.

23. The first border router of claim 13,

wherein the LDP message includes a forwarding equivalence class (FEC) element comprising a PWid field that defines a type of the FEC element, and

wherein the LDP module parses the LDP message to extract data stored to the PWid field, determines the type of the FEC element based on the extracted data stored to the PWid field and parses the FEC element based on the determined type.

24. The first border router of claim 13, wherein each of the first and second provider edge devices comprise one of a router, a digital subscriber line access multiplexor (DSLAM), a cable modem termination system (CMTS), and a switch.

25. A network system comprising:

a first customer network that includes a first customer edge device positioned at the edge of the first customer network;

a second customer network that includes a second customer edge device positioned at the edge of the second customer network;

a first domain that includes;

a first network device positioned at a border of the first domain; and

a first provider edge device positioned at an edge of the first domain that is communicatively coupled to the first network device and the first customer edge device; and

a second domain that includes;

a second network device positioned at a border of the second domain that is communicatively coupled to the first network device; and

a second provider edge device positioned at an edge of the second domain that is communicatively coupled to the second network device and the second customer edge device,

wherein the first network device includes;

at least one interface that receives a label distribution protocol (LDP) message from the first provider edge device in accordance with a label distribution protocol (LDP),

wherein the LDP message includes a forwarding equivalence class-128 (FEC-128) element that stores data for configuring a cross-domain pseudowire (PW) including a group identifier field that stores group identifier data defining a group identifier, a pseudowire (PW) identifier field that stores PW identifier data defining a PW identifier and a provider edge (PE) device address field that stores PE address data defining a PE address assigned to the first provider edge device,

wherein the first provider edge device only supports a forwarding equivalence class-128 (FEC-128) element of LDP to define the data for configuring the cross-domain PW, and

wherein the second provider edge device only supports a FEC-129 element of LDP to define the data for configuring the cross-domain PW;

a control unit that includes;

an LDP module that parses the received LDP message to extract the group identifier data, the PW identifier data and the PE address data from the FEC-128 element of the LDP message;

a translation module that transforms the group identifier data, the PW identifier data and the PE address data to conform to one or more extensible fields for advertising the cross-domain PW configuration data of a routing protocol different from the LDP; and

a routing protocol module that forms a routing protocol message to include the one or more extensible fields to contain the group identifier data, the PW identifier data and the PE address data extracted from the LDP message,

wherein the at least one interface outputs the routing protocol message to the second network device to establish the cross-domain PW from the first provider edge device to the second provider edge device located at an edge of the second domain of the computer network to span the first domain and the second domain; and

wherein the second network device includes;

at least one interface that receives the routing protocol message; and

a control unit that includes;

a routing protocol module that parses the received routing protocol message to extract the group identifier data, the PW identifier data and the PE address data stored to the one or more extensible fields;

a translation module that transforms the extracted group identifier data, the extracted PW identifier data and the extracted PE address data to generate transformed data that conforms to the FEC-129 element; and

an LDP module that generates an LDP message having a FEC-129 element that stores the transformed data,

wherein the at least one interface of the second network device outputs the LDP message having the FEC-129 element to the second provider edge device.

26. A non-transitory computer-readable storage medium comprising instructions for causing a processor to:

receive, with a first border router, a label distribution protocol (LDP) message from a first provider edge device in accordance with a label distribution protocol, the first border router is positioned between a first domain and a second domain of a computer network and in communication with a second intermediate device of the second domain, wherein the first provider edge device is located at an edge of the first domain of the computer network, and wherein the LDP message includes data for configuring a cross-domain pseudowire (PW) as a multi-segment pseudowire (MS-PW);

parse, with the first border router, the received LDP message to extract the data for configuring the cross-domain PW;

transform, with the first border router, the extracted data to conform to a format defined by a routing protocol that includes extensions for advertising the cross-domain PW configuration data, wherein the routing protocol is different than the LDP;

form, with the first border router, a routing protocol message that includes the transformed data; and

output, with the first border router, the routing protocol message to the second border router to establish the cross-domain PW from the first provider edge device to a second provider edge device located at an edge of the second domain of the computer network to span the first domain and the second domain;

receive an encapsulated layer 2 (L2) data unit from the second border router, wherein the encapsulated L2 data unit comprises a header specifying a label stack containing a first label reserved by the first border router for use by a first segment of the MS-PW and a L2 data unit, and wherein the first segment of the MS-PW comprises a first pseudowire (PW) between the first and second border routers;

remove the label from the label stack of the header of the encapsulated L2 data unit;

push a second label reserved by the first provider edge device for use by a second segment of the MS-PW onto the label stack of the header of the encapsulated L2 data unit, wherein the second segment of the MS-PW comprises a second PW between the first provider edge device and the first border router; and

after pushing the second label onto the label stack, forward the encapsulated L2 data unit to the first provider edge device for delivery to a customer network.

27. A method comprising:

receiving, with a first-route reflector, a label distribution protocol (LDP) message from a first provider edge device in accordance with the label distribution protocol (LDP), the first route reflector is positioned between a first domain and a second domain of a computer network and in communication with a second route reflector of the second domain, wherein the first provider edge device is located at an edge of the first domain of the computer network, and wherein the LDP message includes data for configuring a cross-domain pseudowire (PW) as a single-segment pseudowire (SS-PW);

parsing, with the first route reflector, the received LDP message to extract the data for configuring the cross-domain PW, the data including a label assigned to the SS-PW by the first provider edge device;

transforming, with the first route reflector, the extracted data to conform to a format defined by a routing protocol different from the LDP that includes extensions for advertising the cross-domain PW configuration data;

forming, with the first route reflector, a routing protocol message to include the transformed data so as to signal the label reserved for use by the SS-PW; and

outputting, with the first route reflector, the routing protocol message to the second intermediate device to establish the cross-domain PW from the first provider edge device to a second provider edge device located at an edge of the second domain of the computer network to span the first domain and the second domain;

wherein the second route reflector is positioned between the first route reflector and the second provider edge device,

wherein the first route reflector is positioned between the first provider edge device and the second route reflector.

28. The method of claim 27, wherein the routing protocol that includes extensions for advertising cross-domain PW configuration data comprises the BGP routing protocol that includes network layer reachability information (NLRI) fields defined to carry the data for configuring the cross-domain PW.

29. The method of claim 27, wherein receiving a LDP message comprises receiving a LDP message from a first provider edge device that does not implement extensions to the routing protocol that store the data for configuring the cross-domain PW.

30. The method of claim 27,

wherein the LDP message includes a forwarding equivalence class-128 (FEC-128) element that stores the data for configuring the cross-domain PW,

wherein the FEC-128 element includes a group identifier field that stores group identifier data defining a group identifier and a pseudowire (PW) identifier field that stores PW identifier data defining a PW identifier,

wherein parsing the received LDP message includes parsing the LDP message to extract the group identifier data and the PW identifier data from the FEC-128 element of the LDP message,

wherein transforming the extracted data comprises transforming the group identifier data and the PW identifier data to conform to one or more extensible fields of the routing protocol, and

wherein forming the routing protocol message includes forming the routing protocol message to include the one or more extensible fields to contain the group identifier data and PW identifier data extracted from the LDP message.

31. The method of claim 27,

wherein the LDP message includes a forwarding equivalence class-128 (FEC-128) element that stores the data for configuring the cross-domain PW,

wherein the FEC-128 element includes a group identifier field that stores group identifier data defining a group identifier, a pseudowire (PW) identifier field that stores PW identifier data defining a PW identifier and a provider edge (PE) device address field that stores PE address data defining a PE address assigned to the first provider edge device,

wherein parsing the received LDP message includes parsing the LDP message to extract the group identifier data, the PW identifier data and the PE address data from the FEC-128 element of the LDP message,

wherein transforming the extracted data comprises transforming the group identifier data, the PW identifier data and the PE address data to conform to one or more extensible fields of the routing protocol, and

wherein forming the routing protocol message includes forming the routing protocol message to include the one or more extensible fields to contain the group identifier data, the PW identifier data and the PE address data extracted from the LDP message.

32. The method of claim 31,

wherein the FEC-128 element further includes a nexthop field that stores nexthop data,

wherein parsing the received LDP message further includes parsing the LDP message to extract nexthop data,

wherein transforming the extracted data further includes transforming the nexthop data to conform to the one or more extensible fields of the routing protocol, and

wherein forming the routing protocol message further includes forming the routing protocol message to include the one or more extensible fields that contain nexthop data extracted from the LDP message.

33. The method of claim 27,

wherein the LDP message includes a forwarding equivalence class-129 (FEC-129) element that stores the data for configuring the cross-domain PW,

wherein the FEC-129 element includes an attachment group identifier (AGI) field that stores AGI data defining an AGI, a target attachment individual identifier (TAII) value field that stores TAII data defining a TAII value and a source attachment individual identifier (SAII) value field that stores SAII data defining a SAII value,

wherein parsing the received LDP message includes parsing the LDP message to extract the AGI, SAII and TAII data from the FEC-129 element of the LDP message,

wherein transforming the extracted data comprises transforming the AGI, TAII and SAII data to conform to one or more extensible fields of the routing protocol, and

wherein forming the routing protocol message includes forming the routing protocol message to include the one or more extensible fields to contain the AGI data, the TAII data and the SAII data.

34. The method of claim 33,

wherein the FEC-129 element further includes a nexthop field that stores nexthop data,

wherein parsing the received LDP message further includes parsing the LDP message to extract nexthop data,

wherein transforming the extracted data further includes transforming the nexthop data to conform to the one or more extensible fields of the routing protocol, and

wherein forming the routing protocol message further includes forming the routing protocol message to include the one or more extensible fields that contain nexthop data extracted from the LDP message.

35. A first route reflector positioned between a first domain and a second domain of a computer network and in communication with a second route reflector of the second domain, the first route reflector comprising:

at least one interface that receives a label distribution protocol (LDP) message from a first provider edge device in accordance with a label distribution protocol (LDP), wherein the first provider edge device is located at an edge of the first domain of the computer network, and wherein the LDP message includes data for configuring a cross-domain pseudowire (PW) as a single-segment pseudowire (SS-PW);

a control unit that includes;

an LDP module that parses the received LDP message to extract the data for configuring the cross-domain PW, the data including a label assigned to the SS-PW by the first provider edge device;

a translation module that transforms the extracted data to conform to a format defined by a routing protocol different from the LDP that includes extensions for advertising the cross-domain PW configuration data; and

a routing protocol module that forms a routing protocol message that includes the transformed data so as to signal the label reserved for use by the SS-PW, wherein the at least one interface outputs the routing protocol message to the second intermediate device to establish the cross-domain PW from the first provider edge device to a second provider edge device located at an edge of the second domain of the computer network to span the first domain and the second domain;

wherein the second route reflector is positioned between the first route reflector and the second provider edge device,

wherein the first route reflector is positioned between the first provider edge device and the second route reflector.

36. The first route reflector of claim 35, wherein the routing protocol that includes extensions for advertising cross-domain PW configuration data comprises the BGP routing protocol that includes network layer reachability information (NLRI) fields defined to carry the data for configuring the cross-domain PW.

37. The first route reflector of claim 35, wherein the at least one interface receives an LDP message from a first provider edge device that does not implement extensions to the routing protocol that store the data for configuring the cross-domain PW.

38. The first route reflector of claim 35,

wherein the LDP message includes a forwarding equivalence class-128 (FEC-128) element that stores the data for configuring the cross-domain PW,

wherein the FEC-128 element includes a group identifier field that stores group identifier data defining a group identifier and a pseudowire (PW) identifier field that stores PW identifier data defining a PW identifier,

wherein the LDP module parses the LDP message to extract the group identifier data and the PW identifier data from the FEC-128 element of the LDP message,

wherein the translation module transforms the group identifier data and the PW identifier data to conform to one or more extensible fields of the routing protocol, and

wherein the routing protocol module forms the routing protocol message to include the one or more extensible fields to contain the group identifier data and PW identifier data extracted from the LDP message.

39. The first route reflector of claim 35,

wherein the LDP message includes a forwarding equivalence class-128 (FEC-128) element that stores the data for configuring the cross-domain PW,

wherein the FEC-128 element includes a group identifier field that stores group identifier data defining a group identifier, a pseudowire (PW) identifier field that stores PW identifier data defining a PW identifier and a provider edge (PE) device address field that stores PE address data defining a PE address assigned to the first provider edge device,

wherein the LDP module parses the LDP message to extract the group identifier data, the PW identifier data and the PE address data from the FEC-128 element of the LDP message,

wherein the translation module transforms the group identifier data, the PW identifier data and the PE address data to conform to one or more extensible fields of the routing protocol, and

wherein the routing protocol module forms the routing protocol message to include the one or more extensible fields to contain the group identifier data, the PW identifier data and the PE address data extracted from the LDP message.

40. The first route reflector of claim 39,

wherein the FEC-128 element further includes a nexthop field that stores nexthop data,

wherein the LDP module parses the LDP message to extract nexthop data,

wherein the translation module transforms the nexthop data to conform to the one or more extensible fields of the routing protocol, and

wherein the routing protocol module forms the routing protocol message to include the one or more extensible fields that contain nexthop data extracted from the LDP message.

41. The first route reflector of claim 35,

wherein the LDP message includes a forwarding equivalence class-129 (FEC-129) element that stores the data for configuring the cross-domain PW,

wherein the FEC-129 element includes an attachment group identifier (AGI) field that stores AGI data defining an AGI, a target attachment individual identifier (TAII) value field that stores TAII data defining a TAII value and a source attachment individual identifier (SAII) value field that stores SAII data defining a SAII value,

wherein the LDP module parses the LDP message to extract the AGI, SAII and TAII data from the FEC-129 element of the LDP message,

wherein the translation module transforms the AGI, TAII and SAII data to conform to one or more extensible fields of the routing protocol, and

wherein the routing protocol module forms the routing protocol message to include the one or more extensible fields to contain the AGI data, the TAII data and the SAII data.

42. The first route reflector of claim 41,

wherein the FEC-129 element further includes a nexthop field that stores nexthop data,

wherein the LDP module parses the LDP message to extract nexthop data,

wherein the translation module transforms the nexthop data to conform to the one or more extensible fields of the routing protocol, and

wherein the routing protocol module forms the routing protocol message to include the one or more extensible fields that contain nexthop data extracted from the LDP message.

43. A non-transitory computer-readable storage medium comprising instructions for causing a processor of a first route reflector to:

receive a label distribution protocol (LDP) message from a first provider edge device in accordance with the label distribution protocol (LDP), the first route reflector is positioned between a first domain and a second domain of a computer network and in communication with a second route reflector of the second domain, wherein the first provider edge device is located at an edge of the first domain of the computer network, and wherein the LDP message includes data for configuring a cross-domain pseudowire (PW) as a single-segment pseudowire (SS-PW);

parse the received LDP message to extract the data for configuring the cross-domain PW, the data including a label assigned to the SS-PW by the first provider edge device;

transform the extracted data to conform to a format defined by a routing protocol different from the LDP that includes extensions for advertising the cross-domain PW configuration data;

form a routing protocol message to include the transformed data so as to signal the label reserved for use by the SS-PW; and

output the routing protocol message to the second intermediate device to establish the cross-domain PW from the first provider edge device to a second provider edge device located at an edge of the second domain of the computer network to span the first domain and the second domain;

wherein the second route reflector is positioned between the first route reflector and the second provider edge device,

wherein the first route reflector is positioned between the first provider edge device and the second route reflector.