Multicast dual join for ring network topologies
A network node includes a primary incoming interface, a secondary incoming interface and a data flow control unit. The primary incoming interface is operable to receive traffic associated with a particular source and multicast group. The secondary incoming interface is operable to serve as a backup interface if the primary incoming interface or a transmission path coupled to the primary incoming interface is inoperative. The data flow control unit is operable to determine whether the network node is part of a ring topology and if so, forward traffic received on the primary incoming interface associated with the source and multicast group to both a host which joined the multicast group and the secondary incoming interface and forward traffic received on the secondary incoming interface associated with the source and multicast group to the primary incoming interface.
1. A network node for deployment in a packet-switched network, the network node comprising:
a primary incoming interface operable to receive traffic associated with a particular source and multicast group;
a secondary incoming interface operable to serve as a backup interface if the primary incoming interface or a transmission path coupled to the primary incoming interface is inoperative; and
a data flow control unit operable to determine whether the network node is part of a ring topology and if so, forward traffic received on the primary incoming interface associated with the source and multicast group to both a host which joined the multicast group and the secondary incoming interface and forward traffic received on the secondary incoming interface associated with the source and multicast group to the primary incoming interface.
2. The network node of claim 1 , wherein the data flow control unit is operable to multicast the traffic received on the primary incoming interface to the host over one or more outgoing interfaces of the network node and to the secondary incoming interface.
3. The network node of claim 1 , wherein the data flow control unit is operable to determine the network node is part of a ring topology responsive to a multicast message received on the primary incoming interface, the multicast message indicating a plurality of incoming interfaces per route.
4. The network node of claim 3 , wherein the multicast message is a protocol independent multicast dual join message.
5. The network node of claim 1 , wherein the data flow control unit is operable to determine whether the network node is part of a ring topology responsive to control signaling received from an operator of the network.
6. The network node of claim 1 , wherein the network node is a router.
7. The network node of claim 1 , wherein the data flow control unit is further operable to determine if the primary incoming interface or a transmission path coupled to the primary incoming interface is inoperative when the network node is part of a ring topology, and if so forward the traffic received on the secondary incoming interface to the host.
8. The network node of claim 7 , wherein the data flow control unit is operable to forward the traffic received on the secondary incoming interface to the host when the primary incoming interface or a transmission path coupled to the primary incoming interface is inoperative and the network node is part of a ring topology by multicasting the traffic received on the secondary incoming interface to the host over one or more outgoing interfaces of the network node.
9. The network node of claim 7 , wherein the data flow control unit is operable to forward the traffic received on the secondary incoming interface to the host when the primary incoming interface or a transmission path coupled to the primary incoming interface is inoperative and the network node is part of a ring topology without control plane notification.
10. The network node of claim 7 , wherein the data flow control unit is operable to determine if the primary incoming interface or a transmission path coupled to the primary incoming interface is inoperative responsive to control plane signaling received at the network node.
11. The network node of claim 7 , wherein the data flow control unit is operable to determine the primary incoming interface or a transmission path coupled to the primary incoming interface is inoperative by detecting a physical link failure on the primary incoming interface.
12. The network node of claim 1 , wherein the data flow control unit is further operable to drop the traffic received on the secondary incoming interface when the network node is not part of a ring topology.
13. A method of operating a network node deployed in a packet-switched network, the method comprising:
receiving traffic associated with a particular source and multicast group on a primary incoming interface of the network node;
using a secondary incoming interface of the network node as a backup interface if the primary incoming interface or a transmission path coupled to the primary incoming interface is inoperative;
determining whether the network node is part of a ring topology; and
if the network node is part of a ring topology, forwarding traffic received on the primary incoming interface associated with the source and multicast group to both a host which joined the multicast group and the secondary incoming interface and forwarding traffic received on the secondary incoming interface associated with the source and multicast group to the primary incoming interface.
14. The method of claim 13 , comprising multicasting the traffic received on the primary incoming interface to the host over one or more outgoing interfaces of the network node and to the secondary incoming interface.
15. The method of claim 13 , comprising:
receiving a multicast message on the primary incoming interface, the multicast message indicating a plurality of incoming interfaces per route; and
determining the network node is part of a ring topology responsive to the primary incoming interface receiving the multicast message.
16. The method of claim 15 , wherein the multicast message is a protocol independent multicast dual join message.
17. The method of claim 13 , comprising determining whether the network node is part of a ring topology responsive to control signaling received from an operator of the network.
18. The method of claim 13 , further comprising determining whether the primary incoming interface or a transmission path coupled to the primary incoming interface is inoperative when the network node is part of a ring topology, and if so forward the traffic received on the secondary incoming interface to the host.
19. The method of claim 18 , comprising multicasting the traffic received on the secondary incoming interface to the host over one or more outgoing interfaces of the network node when the primary incoming interface or a transmission path coupled to the primary incoming interface is inoperative and the network node is part of a ring topology.
20. The method of claim 18 , comprising forwarding the traffic received on the secondary incoming interface to the host when the primary incoming interface or a transmission path coupled to the primary incoming interface is inoperative and the network node is part of a ring topology without control plane notification.
21. The method of claim 18 , comprising determining whether the primary incoming interface or a transmission path coupled to the primary incoming interface is inoperative responsive to control plane signaling received at the network node.
22. The method of claim 18 , comprising determining the primary incoming interface or a transmission path coupled to the primary incoming interface is inoperative by detecting a physical link failure on the primary incoming interface.
23. The method of claim 13 , further comprising dropping the traffic received on the secondary incoming interface when the network node is not part of a ring topology.