Method and apparatus for providing congruent multicast and unicast routing

• US 7,969,978 B2
• Filed: 11/25/2009
• Issued: 06/28/2011
• Est. Priority Date: 10/25/2006
• Status: Expired due to Fees

• Current Assignee: AT&T Corporation (AT&T, Inc.)
• Original Assignee: AT&T Intellectual Property II LP (AT&T, Inc.)
• Inventors: Napierala, Maria
• Primary Examiner(s): Phunkulh; Bob A
• Application Number:
  US12/626,049
• Publication Number:
  US 20100067528A1
• Time in Patent Office: 580 Days
• Field of Search: None
• US Class Current: 370/389
• CPC Class Codes: H04L 12/1836 with heterogeneous network architecture
• CPC Class Codes: H04L 12/4641 Virtual LANs, VLANs, e.g. virtual private networks [VPN] LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272
• CPC Class Codes: H04L 45/04 Interdomain routing, e.g. hierarchical routing
• CPC Class Codes: H04L 45/50 using label swapping, e.g. multi-protocol label switch [MPLS]

Abstract

A method and apparatus for enabling congruent multicast and unicast routing in a Virtual Private Network (VPN) are disclosed. For example, the present method receives a request to join a multicast group to receive multicast data traffic by a receiver behind a remote Provider Edge (PE) router. The method then discovers a multicast source to allow said remote PE router to use a direct path to receive said multicast data traffic from a source.

Claims

1. A method for enabling congruent multicast and unicast routing in a virtual private network, comprising:

receiving a request to join a multicast group to receive multicast data traffic from a receiver behind a router; and

discovering a multicast source to allow the router to use a direct path to receive the multicast data traffic from a source, wherein the discovering comprises;

receiving a join message by a first provider edge router with a customer rendezvous point behind the first provider edge router from the router;

sending the received join message by the first provider edge router to the customer rendezvous point without forwarding multicast traffic on an interface that leads toward the virtual private network; and

announcing the multicast source,

wherein the virtual private network is a multi-protocol label switching/border gateway protocol multicast virtual private network.

2. The method of claim 1, wherein the announcing comprises:

sending a prune message by the first provider edge router to the customer rendezvous point when a first multicast packet is received from the multicast source by the first provider edge router;

sending a source announcement message by the first provider edge router to indicate the multicast source and a location of the multicast source to all other provider edge routers in the virtual private network; and

signaling an existence of the multicast source and a tunnel identifier to be used for multicast traffic to the all other provider edge routers in the virtual private network by a second provider edge router with the multicast source behind the second provider edge router when the second provider edge router receives the source announcement message from the first provider edge router.

3. The method of claim 2, wherein the source announcement message comprises a source address of the first multicast packet extracted from the first multicast packet.

4. The method of claim 1, wherein the discovering further comprises:

translating a first join message to a second join message by each provider edge router with a multicast group receiver behind the each provider edge router;

sending the second join message by the each provider edge router to a best next hop router towards the multicast source; and

joining a tunnel for a distribution tree announced by the best next hop router.

5. The method of claim 1, wherein the router comprises a remote provider edge router.

6. The method of claim 1, wherein the router comprises a locally connected customer edge router.

7. A method for enabling congruent multicast and unicast routing in a virtual private network, comprising:

receiving a request to join a multicast group to receive multicast data traffic from a receiver behind a router; and

discovering a multicast source to allow the router to use a direct path to receive the multicast data traffic from a source, wherein the discovering comprises;

receiving a first join message by a provider edge router with a multicast source behind the provider edge router from the router;

announcing a tunnel to be used for multicast traffic to all remote provider edge routers in the virtual private network by the provider edge router; and

joining the tunnel for a distribution tree announced by a remote provider edge router with a multicast group receiver behind the remote provider edge router only if the provider edge router is a best next hop router from the remote provider edge router to the multicast source,

wherein the virtual private network is a multi-protocol label switching/border gateway protocol multicast virtual private network.

8. A non-transitory computer-readable medium having stored thereon a plurality of instructions, the plurality of instructions including instructions which, when executed by a processor, cause the processor to perform a method for enabling congruent multicast and unicast routing in a virtual private network, comprising:

receiving a request to join a multicast group to receive multicast data traffic from a receiver behind a router; and

discovering a multicast source to allow the router to use a direct path to receive the multicast data traffic from a source, wherein the discovering comprises;

receiving a join message by a first provider edge router with a customer rendezvous point behind the first provider edge router from the router;

sending the received join message by the first provider edge router to the customer rendezvous point without forwarding multicast traffic on an interface that leads toward the virtual private network; and

announcing the multicast source,

wherein the virtual private network is a multi-protocol label switching/border gateway protocol multicast virtual private network.

9. The non-transitory computer-readable medium of claim 8, wherein the announcing comprises:

sending a prune message by the first provider edge router to the customer rendezvous point when a first multicast packet is received from the multicast source by the first provider edge router;

sending a source announcement message by the first provider edge router to indicate the multicast source and a location of the multicast source to all other provider edge routers in the virtual private network; and

signaling an existence of the multicast source and a tunnel identifier to be used for multicast traffic to the all other provider edge routers in the virtual private network by a second provider edge router with the multicast source behind the second provider edge router when the second provider edge router receives the source announcement message from the first provider edge router.

10. The non-transitory computer-readable medium of claim 9, wherein the source announcement message comprises a source address of the first multicast packet extracted from the first multicast packet.

11. The non-transitory computer-readable medium of claim 8, wherein the discovering further comprises:

translating a first join message to a second join message by each provider edge router with a multicast group receiver behind the each provider edge router;

sending the second join message by the each provider edge router to a best next hop router towards the multicast source; and

joining a tunnel for a distribution tree announced by the best next hop router.

12. The non-transitory computer readable medium of claim 8, wherein the router comprises a remote provider edge router.

13. The non-transitory computer readable medium of claim 8, wherein the router comprises a locally connected customer edge router.

14. A non-transitory computer-readable medium having stored thereon a plurality of instructions, the plurality of instructions including instructions which, when executed by a processor, cause the processor to perform a method for enabling congruent multicast and unicast routing in a virtual private network, comprising:

receiving a request to loin a multicast group to receive multicast data traffic from a receiver behind a router; and

discovering a multicast source to allow the router to use a direct path to receive the multicast data traffic from a source, wherein the discovering comprises;

receiving a first join message by a provider edge router with a multicast source behind the provider edge router from the router;

announcing a tunnel to be used for multicast traffic to all remote provider edge routers in the virtual private network by the provider edge router; and

joining the tunnel for a distribution tree announced by a remote provider edge router with a multicast group receiver behind the remote provider edge router only if the provider edge router is a best next hop router from the remote provider edge router to the multicast source, wherein the virtual private network is a multi-protocol label switching/border gateway protocol multicast virtual private network.

15. An apparatus for enabling congruent multicast and unicast routing in a virtual private network, comprising:

means for receiving a request to join a multicast group to receive multicast data traffic from a receiver behind a router; and

means for discovering a multicast source to allow the router to use a direct path to receive the multicast data traffic from a source, wherein the discovering means comprises;

means for receiving a join message by a first provider edge router with a customer rendezvous point behind the first provider edge router from the router;

means for sending the received join message by the first provider edge router to the

customer rendezvous point without forwarding multicast traffic on an interface that leads toward the virtual private network; and

means for announcing the multicast source,

wherein the virtual private network is a multi-protocol label switching/border gateway protocol multicast virtual private network.

16. The apparatus of claim 15, wherein the announcing means comprises:

means for sending a prune message by the first provider edge router to the customer rendezvous point when a first multicast packet is received from the multicast source by the first provider edge router;

means for sending a source announcement message by the first provider edge router to indicate the multicast source and a location of the multicast source to all other provider edge routers in the virtual private network; and

means for signaling an existence of the multicast source and a tunnel identifier to be used for multicast traffic to the all other provider edge routers in the virtual private network by a second provider edge router with the multicast source behind the second provider edge router when the second provider edge router receives the source announcement message from the first provider edge router.

17. The apparatus of claim 16, wherein the source announcement message comprises a source address of the first multicast packet extracted from the first multicast packet.

18. The apparatus of claim 15, wherein the discovering means further comprises:

means for translating a first join message to a second join message by each provider edge router with a multicast group receiver behind the each provider edge router;

means for sending the second join message by the each provider edge router to a best next hop router towards the multicast source; and

means for joining a tunnel for a distribution tree announced by the best next hop router.

19. The apparatus of claim 15, wherein the router comprises a remote provider edge router.

20. The apparatus of claim 15, wherein the router comprises a locally connected customer edge router.