DYNAMIC DETERMINATION OF THE ROOT NODE OF AN MLDP TUNNEL

1 . An apparatus, comprising:

a processor and a memory communicatively connected to the processor, the processor configured to:

receive a request to join a multicast group supported by a multicast source;

determine a route to the multicast source;

determine, based on the route, a next-hop node associated with the route and a routing protocol used to advertise the route to the next-hop node; and

determine, based on the routing protocol and the next-hop node, an advertising node that used the routing protocol to advertise the route to the next-hop node.

2 . The apparatus of claim 1 , wherein the request to join the multicast group is received via a Protocol Independent Multicast (PIM) protocol.

3 . The apparatus of claim 1 , wherein the processor is configured to determine the route to the multicast source based on an identifier of the multicast source.

4 . The apparatus of claim 1 , wherein the processor is configured to determine the route to the multicast source by querying a routing table using an identifier of the multicast source to identify a routing table entry comprising route information associated with the route to the multicast source.

5 . The apparatus of claim 1 , wherein the processor is configured to determine the next-hop node and the routing protocol from a routing table entry comprising route information associated with the route.

6 . The apparatus of claim 1 , wherein the processor is configured to determine the advertising node by querying the routing protocol based on an identifier of the next-hop node.

7 . The apparatus of claim 1 , wherein the routing protocol comprises at least one of an Open Shortest Path First (OSPF) protocol, an Intermediate System to Intermediate System (ISIS) protocol, or a Border Gateway Protocol (BGP) protocol.

8 . The apparatus of claim 1 , wherein the processor is configured to:

determine information identifying the multicast source and the multicast group (multicast SG);

encode the information identifying the multicast SG into a Multicast Label Distribution Protocol (MLDP) Forwarding Equivalence Class (FEC); and

initiate a request for the MLDP to establish, based on the MLDP FEC, an MLDP tunnel rooted at the advertising node.

9 . The apparatus of claim 8 , wherein the processor is configured to:

initiate propagation of the MLDP FEC toward the advertising node.

10 . The apparatus of claim 1 , wherein the processor is configured to support a Protocol Independent Multicast (PIM) protocol and a Multicast Label Distribution Protocol (MLDP).

11 . A method, comprising:

using a processor and a memory for:

receiving a request to join a multicast group supported by a multicast source;

determining a route to the multicast source;

determining, based on the route, a next-hop node associated with the route and a routing protocol used to advertise the route to the next-hop node; and

determining, based on the routing protocol and the next-hop node, an advertising node that used the routing protocol to advertise the route to the next-hop node.

12 . The method of claim 11 , wherein the request to join the multicast group is received via a Protocol Independent Multicast (PIM) protocol.

13 . The method of claim 11 , wherein the route to the multicast source is determined based on an identifier of the multicast source.

14 . The method of claim 11 , wherein determining the route to the multicast source comprises:

querying a routing table using an identifier of the multicast source to identify a routing table entry comprising route information associated with the route to the multicast source.

15 . The method of claim 11 , wherein the next-hop node and the routing protocol are determined from a routing table entry comprising route information associated with the route.

16 . The method of claim 11 , wherein determining the advertising node comprises:

querying the routing protocol based on an identifier of the next-hop node.

17 . The method of claim 11 , wherein the routing protocol comprises at least one of an Open Shortest Path First (OSPF) protocol, an Intermediate System to Intermediate System (ISIS) protocol, or a Border Gateway Protocol (BGP) protocol.

18 . The method of claim 11 , further comprising:

determining information identifying the multicast source and group (multicast SG);

encoding the information identifying the multicast SG into a Multicast Label Distribution Protocol (MLDP) Forwarding Equivalence Class (FEC); and

initiating a request for the MLDP to establish, based on the MLDP FEC, an MLDP tunnel rooted at the advertising node.

19 . The method of claim 18 , further comprising:

initiating propagation of the MLDP FEC toward the advertising node.

20 . The method of claim 11 , wherein the processor is configured to support a Protocol Independent Multicast (PIM) protocol and a Multicast Label Distribution Protocol (MLDP).