DYNAMIC UPDATE OF A MULTICAST TREE

• US 20090067348A1
• Filed: 09/11/2007
• Published: 03/12/2009
• Est. Priority Date: 09/11/2007
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Novello, Stefano, Previdi, Stefano Benedetto, Vasseur, Jean-Philippe Marcel
• Granted Patent: US 8,077,713 B2
• Time in Patent Office: Days
• US Class Current: 370/256
• CPC Class Codes: H04L 45/04 Interdomain routing, e.g. hierarchical routing
• CPC Class Codes: H04L 45/16 Multipoint routing
• CPC Class Codes: H04L 45/48 Routing tree calculation
• CPC Class Codes: H04L 45/50 using label swapping, e.g. multi-protocol label switch [MPLS]

Abstract

In an example embodiment, a multicast tree is accessed. The multicast tree defines one or more destination label switch routers and paths from a source label switch router to the destination label switch routers. Multicast addresses are then transmitted to the destination label switch routers. In an example embodiment, upon receipt of the multicast addresses, a request to update the multicast tree is transmitted. The request includes the identifier of the label switch router that originated the request.

Claims

1. A method comprising:

accessing a multicast tree that defines a destination label switch router and a path from a source label switch router to the destination label switch router; and

transmitting a multicast address to the destination label switch router.

2. The method of claim 1, further comprising:

receiving a request to join a multicast group associated with the multicast address, the request including an identifier of a new label switch router; and

adding the new label switch router to the multicast tree.

3. The method of claim 2, further comprising:

receiving a cost associated with a transmission of data between the destination label switch router and the new label switch router; and

computing a path to the new label switch router based on the cost.

4. The method of claim 1, further comprising:

receiving a request to leave a multicast group associated with the multicast address, the request including an identifier of the destination label switch router; and

deleting the destination label switch router from the multicast tree.

5. The method of claim 1, wherein the multicast tree is a multicast control tree that defines a plurality of destination label switch routers, each of the plurality of destination label switch routers being associated with a different domain.

6. The method of claim 5, wherein the different domain is from a list of a plurality of predefined domains.

7. The method of claim 1, wherein the multicast tree is a multicast data tree that defines a plurality of destination label switch routers, each of the plurality of destination label switch routers being associated with a domain.

8. An apparatus comprising:

a processor; and

a memory in communication with the processor, the memory comprising instructions executable by the processor, when executed the processor being operable to;

receive a multicast address; and

transmit a request to update a multicast tree, the request including an identifier of a label switch router that originated the request.

9. The apparatus of claim 8, wherein the request is transmitted to a source label switch router.

10. The apparatus of claim 8, wherein the request is to join a multicast group associated with the multicast address, the request being transmitted by way of an interior gateway protocol.

11. The apparatus of claim 8, wherein the request is to leave a multicast group associated with the multicast address.

12. The apparatus of claim 8, wherein the multicast tree is a multicast control tree that defines a plurality of destination label switch routers and a plurality of paths from a source label switch router to the plurality of destination label switch routers, each of the plurality of destination label switch routers defined in the multicast control tree being associated with a different domain.

13. The apparatus of claim 8, wherein the multicast tree is a multicast data tree that defines a plurality of destination label switch routers and a plurality of paths from a source label switch router to the plurality of destination label switch routers, each of the plurality of destination label switch routers defined in the multicast data tree being associated with a domain.

14. An apparatus comprising:

a processor; and

a memory in communication with the processor, the memory comprising instructions executable by the processor, when executed the processor being operable to;

access a multicast tree that defines a plurality of destination label switch routers and a plurality of paths from a source label switch router to the plurality of destination label switch routers; and

transmit a multicast address to the plurality of destination label switch routers.

15. The apparatus of claim 14, wherein when executed the processor being further operable to:

receive a request to join a multicast group associated with the multicast address, the request including an identifier of a new label switch router; and

add the new label switch router to the multicast tree.

16. The apparatus of claim 15, wherein when executed the processor being further operable to:

receive a cost associated with a transmission of data between a destination label switch router from the plurality of destination label switch routers and the new label switch router; and

compute a path to the new label switch router based on the cost.

17. The apparatus of claim 14, wherein when executed the processor being further operable to:

receive a request to leave a multicast group associated with the multicast address, the request including an identifier of a destination label switch router from the plurality of destination label switch routers; and

delete the destination label switch router from the multicast tree.

18. The apparatus of claim 14, wherein the multicast tree is a multicast control tree, each of the plurality of destination label switch routers defined in the multicast control tree being associated with a different domain.

19. The apparatus of claim 18, wherein the different domain is from a list of a plurality of predefined domains.

20. The apparatus of claim 14, wherein the multicast tree is a multicast data tree, each of the plurality of destination label switch routers defined in the multicast data tree being associated with a domain.

21. An apparatus comprising:

a first means for accessing a multicast tree that defines a destination label switch router and a path from a source label switch router to the destination label switch router; and

a second means for transmitting a multicast address to the destination label switch router.