Optimal bridging over MPLS/IP through alignment of multicast and unicast paths

• US 8,169,924 B2
• Filed: 12/07/2005
• Issued: 05/01/2012
• Est. Priority Date: 08/01/2005
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Sajassi, Ali, Farinacci, Dino, Zwiebel, John M., Alvarez, Daniel
• Primary Examiner(s): GREY, CHRISTOPHER P
• Application Number:
  US11/296,550
• Publication Number:
  US 20070025277A1
• Time in Patent Office: 2,337 Days
• Field of Search: 370/432, 370/400, 370/408, 370/352, 370/390, 370/312, 370/396, 370/236.1, 370/236.2, 370241-251, 370254-256, 714/716, 714/717
• US Class Current: 370/249
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/26 Route discovery packet

Abstract

A provider edge (PE) node of a network operates to send a trace path message over the network to a receiver PE node, the trace path message recording a list of intermediate nodes of a unicast path from the PE node to the receiver PE node; and receive a join message initiated from the receiver PE node, the join message using the list to propagate to the source PE node through the intermediate nodes such that a branch of a multicast tree is aligned with the unicast path. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).

Claims

1. A method of operation for a provider edge (PE) node of a network, comprising:

sending a plurality of trace path messages over the network to a corresponding plurality of receiver PE nodes, each trace path message recording a corresponding list of intermediate nodes of an established unicast path from the PE node to a corresponding one of the receiver PE nodes; and

receiving a plurality of Protocol Independent Multicast (PIM) ioin messages, each PIM join message being initiated from the corresponding one of the receiver PE nodes, each PIM join message using the corresponding list to propagate to the PE node through the intermediate nodes to build a multicast distribution tree for multicast data transmission such that each branch of the multicast distribution tree is aligned with the established unicast path.

2. The method of claim 1 wherein the network comprises an Internet Protocol (IP) network.

3. A method of operation for a provider edge (PE) node of a network, comprising:

receiving a trace path message sent over the network hop-by-hop from a source PE node, the trace path message recording a list of intermediate nodes of an established unicast path from the source PE node to the PE node;

terminating the trace path message; and

issuing a Protocol Independent Multicast (PIM) join message to build a branch of a multicast distribution tree, the PIM join message using the list to propagate to the source PE node through the intermediate nodes such that the branch of the multicast distribution tree is built aligned with the established unicast path.

4. The method of claim 3 wherein the network comprises an Internet Protocol (IP) network.

5. The method of claim 3 wherein network comprises a Multi-protocol label switching (MPDS)/Internet Protocol (IP) network.

6. A provider edge (PE) node comprising:

a port for connection with a network; and

a processing unit coupled to theport and configured to send a plurality of trace path messages over the network to a corresponding plurality of receiver PE nodes, each trace path message recording a corresponding list of intermediate nodes of an established unicast path from the PE node to a corresponding one of the receiver PE nodes, the processing unit being further configured to receive a plurality of Protocol Independent Multicast (PIM) join messages, each PIM join message being initiated from the corresponding one of the receiver PE nodes, each PIM join message using the corresponding list to propagate to the PE node through the intermediate nodes to build a multicast distribution tree for multicast data transmission such that each branch of the multicast distribution tree is aligned with the established unicast path.

7. The PE node of claim 6 wherein the network comprises a Multi-protocol label switching (MPLS)/Internet Protocol (IP) network.

8. The PE node of claim 6 wherein the established unicast path comprises a point-to-point tunnel.

9. A provider edge (PE) node comprising:

a port for connection with a network; and

a processing unit coupled to the port and configured to receive a trace path message sent over the network hop-by-hop from a source PE node, the trace path message recording a list of intermediate nodes of an established unicast path from the source PE node to the PE node, the processing unit being further confiqured to terminate the trace path message and issue a Protocol Independent Multicast (PIM) join message to build a branch of a multicast distribution tree, the PIM join message using the list to propagate to the source PE node through the intermediate nodes such that the branch of the multicast distribution tree is built aligned with the established unicast path.

10. A computer program product comprising a non-transitory computer useable medium and computer readable code embodied on the non-transitory computer useable medium, execution of the computer readable code causing the computer program product to configure a provider edge (PE) node to:

send a plurality of trace path messages over the network to a corresponding plurality of receiver PE nodes, each trace path message recording a corresponding list of intermediate nodes of an established unicast path from the PE node to a corresponding one of the receiver PE nodes; and

receive a plurality of Protocol Independent Multicast (PIM) join messages, each PIM join message being initiated from the corresponding one of the receiver PE nodes, each PIM join message using the corresponding list to propagate to the PE node through the intermediate nodes to build a multicast distribution tree for multicast data transmission such that each branch of the multicast distribution tree is aligned with the established unicast path.

11. The computer program product of claim 10 wherein the network comprises a Multi-protocol label switching (MPLS)/Internet Protocol (IP) network.

12. A computer program product comprising a non-transitory computer useable medium and computer readable code embodied on the non-transitory computer useable medium, execution of the computer readable code causing the computer program product to configure a provider edge (PE) node to:

receive a trace path message sent over the network hop-by-hop from a source PE node, the trace path message recording a list of intermediate nodes of an established unicast path from the source PE node to the PE node;

terminate the trace path message; and

issue a Protocol Independent Multicast (PIM) join message to build a branch of a multicast distribution tree, the PIM join message using the list to propagate to the source PE node through the intermediate nodes such that the branch of the multicast distribution tree is built aligned with the established unicast path.

13. The computer program product of claim 12 wherein the network comprises an Internet Protocol (IP) network.

14. The computer program product of claim 12 wherein network comprises a Multi-protocol label switching (MPLS)/Internet Protocol (IP) network.

15. A system for alignment of multicast and unicast paths over a network, comprising:

a plurality of receiver provider edge (PE) nodes; and

a source provider edge (PE) node operable to send trace path messages over the network, each trace path message recording a corresponding list of intermediate nodes of an established unicast path from the source PE node to a corresponding one of the receiver PE nodes,

wherein each receiver PE node is operable to initiate a Protocol Independent Multicast (PIM) join message for building a multicast distribution tree for multicast data transmission, the PIM join message being sent back to the source PE node upon receiving the trace path message, the PIM join message using the corresponding list to propagate to the source PE node through the intermediate nodes such that each branch of the multicast distribution tree is built aligned with the unicast paths.

16. A method of operation for a service provider (SP) network, comprising:

creating a plurality of unicast paths from a source node to a corresponding plurality of receiver nodes;

sending, by the source node, trace path messages over the network, each trace path message recording a corresponding list of intermediate nodes of one of the unicast paths from the source node to a corresponding one of the receiver nodes; and

sending, by each receiver node, a Protocol Independent Multicast (PIM) join message for building a multicast distribution tree for multicast data transmission, the PIM join message being sent back to the source node upon receipt of the trace path message, the PIM join message using the corresponding list to propagate to the source node through the intermediate nodes such that each branch of the multicast distribution tree is built aligned with the unicast paths.