METHOD TO TRANSPORT BIDIR PIM OVER A MULTIPROTOCOL LABEL SWITCHED NETWORK

• US 20130177018A1
• Filed: 03/04/2013
• Published: 07/11/2013
• Est. Priority Date: 05/29/2007
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Wijnands, Jacob Ijsbrand, Boers, Arjen
• Granted Patent: US 9,083,632 B2
• Time in Patent Office: Days
• US Class Current: 370/390
• CPC Class Codes: H04L 12/18 for broadcast or conference , e.g. multicast
• CPC Class Codes: H04L 12/185 with management of multicast group membership
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04L 45/16 Multipoint routing
• CPC Class Codes: H04L 45/50 using label swapping, e.g. multi-protocol label switch [MPLS]

Abstract

A method, system and an apparatus to transport bidir PIM over a multiprotocol label switched network are provided. The method may comprise receiving a multicast packet at a network element, the multicast packet including an upstream label. The method may further comprise identifying, from the upstream label, a Multicast Distribution Tree (MDT) rooted at a rendezvous point. The packet may be forwarded along the MDT towards the RP based on the upstream label. The MDT may be identified from a downstream label and the packet may be forwarded along the MDT away from the RP based on the downstream label.

Claims

1. A method comprising:

receiving a multicast packet at a network element of a plurality of network elements in a network;

performing a route lookup at each of a plurality of edge router elements of the network;

selecting, based on the lookup, one of the plurality of edge router elements as a root of a Label Switched Path (LSP) of a Multicast Distribution Tree (MDT) rooted at a rendezvous point (RP); and

forwarding the packet along the MDT towards the RP via the root edge router element.

2. The method of claim 1, further comprising:

identifying the MDT based on an upstream label included in the multicast packet; and

forwarding the packet the along the MDT towards the RP based on the upstream label.

3. The method of claim 1, further comprising:

identifying the MDT based on a downstream label included in the multicast pack; and

forwarding the packet the along the MDT away from the RP based on the downstream label.

4. The method of claim 1, wherein the MDT tree extends from the root edge router element to the RP to form a segmented MDT.

5. The method of claim 1, further comprising creating one downstream state and multiple upstream states at provider edge router elements of the network, wherein each provider edge router element acts as a label switched router configured to forward packets based on the upstream label and downstream labels.

6. The method of claim 1, further comprising aggregating Multiple Virtual Private Networks (VPNs) over the MDT, and wherein an ingress provider edge router element of the network allocates a label per VPN.

7. The method claim 1, further comprising:

identifying a multipoint-to-multipoint tree identifier based on a Border Gateway Protocol (BGP) advertisement from the root edge router element; and

using the multipoint-to-multipoint tree identifier as a Forwarding Equivalence Class (FEC).

8. The method of claim 1, wherein the multicast packet is a bidirectional Protocol Independent Multicast (bidir PIM) packet.

9. The method of claim 1, wherein the LSP is a point-to-multipoint (P2MP) LSP or a multipoint-to-multipoint (MP2MP) LSP.

10. An apparatus comprising:

memory to store instructions; and

a processor configured to execute the instructions to;

receive a multicast packet at a network element of a plurality of network elements in a network;

perform a route lookup at each of a plurality of edge router elements of the network;

select, based on the lookup, one of the plurality of edge router elements as a root of a Label Switched Path (LSP) of a Multicast Distribution Tree (MDT) rooted at a rendezvous point (RP); and

forward the packet along the MDT towards the RP via the root edge router element.

11. The apparatus of claim 10, wherein the MDT is identified based on an upstream label included in the multicast packet and the packet is forwarded the along the MDT towards the RP based on the upstream label.

12. The apparatus of claim 10, wherein the MDT is identified based on a downstream label included in the multicast packet and the packet is forwarded the along the MDT away from the RP based on the downstream label.

13. The apparatus of claim 10, wherein the MDT tree extends from the root edge router element to the RP to form a segmented MDT.

14. The apparatus of claim 10, wherein the instructions cause the processor to create one downstream state and multiple upstream states at provider edge router elements of the network, wherein each provider edge router element acts as a label switched router configured to forward packets based on the upstream label and downstream labels.

15. The apparatus of claim 10, wherein the instructions cause the processor to aggregate Multiple Virtual Private Networks (VPNs) over the MDT, and wherein an ingress provider edge router element of the network allocates a label per VPN.

16. The apparatus claim 10, wherein the instructions cause the processor to:

identify a multipoint-to-multipoint tree identifier based on a Border Gateway Protocol (BGP) advertisement from the root edge router element; and

use the multipoint-to-multipoint tree identifier as a Forwarding Equivalence Class (FEC).

17. The apparatus of claim 10, wherein the multicast packet is a bidirectional Protocol Independent Multicast (bidir PIM) packet.

18. The apparatus of claim 10, wherein the LSP is a point-to-multipoint (P2MP) LSP or a multipoint-to-multipoint (MP2MP) LSP.

19. An apparatus comprising:

means for receiving a multicast packet at a network element of a plurality of network elements in a network;

means for performing a route lookup at each of a plurality of edge router elements of the network;

means for selecting, based on the lookup, one of the plurality of edge router elements as a root of a Label Switched Path (LSP) of a Multicast Distribution Tree (MDT) rooted at a rendezvous point (RP); and

means for forwarding the packet along the MDT towards the RP via the root edge router element.

20. The apparatus claim 19, wherein the LSP is a point-to-multipoint (P2MP) LSP or a multipoint-to-multipoint (MP2MP) LSP.