Multicast redundancy in EVPN networks
A system and associated methods provide a scalable solution for managing multiple multicast flows within a multicast group of a multicast network. The system groups redundant sources of the multicast group according to their associated multicast flows, assigns flow identifiers to each redundant source indicative of their associated multicast flows, and facilitates Single Forwarder election to select a Single Forwarder that belongs to the appropriate multicast flow. The system provides control plane extensions that enable signaling of which redundant source belongs to which multicast flow.
1. A method, comprising:
determining, at a provider edge device, a flow identifier for a first source of a multicast group, the flow identifier indicating a multicast flow associated with the first source, and the first source being associated with a first virtual private network and one of a plurality of redundant sources that are commonly associated with the multicast flow and the flow identifier, wherein the plurality of redundant sources are each connected to a Multiprotocol Label Switching network; and
electing, at the provider edge device, a redundant source of the plurality of redundant sources and associated with a second virtual private network as a Single Forwarder from a tuple indicative of the plurality of redundant sources having common flow identifiers.
2. The method of claim 1 , the provider edge device being one of a plurality of provider edge devices connected over a multicast network, each respective provider edge device being in communication with a respective redundant source of the plurality of redundant sources.
3. The method of claim 2 , wherein the provider edge device determines the flow identifier based on a global policy across each provider edge device of the plurality of provider edge devices such that each redundant source commonly associated with the multicast flow exhibits a same value for the flow identifier, the flow identifier being unique to the multicast flow.
4. The method of claim 1 , further comprising:
grouping the plurality of redundant sources associated with the multicast flow, the plurality of redundant sources being a subset of a plurality of sources connected to a plurality of provider edge devices over a multicast network; and
assigning the flow identifier to each redundant source of the plurality of redundant sources.
5. The method of claim 1 , further comprising:
communicating the flow identifier to one or more provider edge devices of a plurality of provider edge devices connected over a multicast network.
6. The method of claim 5 , wherein the flow identifier of the first source is communicated to the plurality of provider edge devices within a flow identifier field using a Selective P-Multicast Service Interface (S-PMSI).
7. The method of claim 1 , further comprising:
communicating the tuple indicative of the plurality of redundant sources having common flow identifiers to one or more provider edge devices of a plurality of provider edge devices connected over a multicast network.
8. The method of claim 7 , wherein the tuple is communicated using a Selective P-Multicast Service Interface (S-PMSI).
9. The method of claim 1 , further comprising:
receiving, at the provider edge device in communication with the first source, a request for content of the multicast flow associated with the flow identifier;
forwarding, at the provider edge device, the request for content to the first source; and
responding, at the first source, to the request for content;
wherein the first source is the Single Forwarder associated with the flow identifier.
10. The method of claim 1 , further comprising:
receiving, at the provider edge device in communication with the first source, a request for content of the multicast flow associated with the flow identifier; and
dropping, at the provider edge device, the request for content;
wherein the first source is not the Single Forwarder associated with the flow identifier.
11. A system, comprising:
a provider edge device having a processor in communication with a memory, the memory including instructions executable by the processor to:
determine a flow identifier for a first source of a multicast group in communication with the provider edge device, the flow identifier indicating a multicast flow associated with the first source, and the first source being associated with a first virtual private network and one of a plurality of redundant sources that are commonly associated with the multicast flow and the flow identifier, wherein the plurality of redundant sources are each connected to a Multiprotocol Label Switching network; and
elect a redundant source of the plurality of redundant sources and associated with a second virtual private network as a Single Forwarder from a tuple indicative of the plurality of redundant sources having common flow identifiers.
12. The system of claim 11 , the provider edge device being one of a plurality of provider edge devices connected over a multicast network, each respective provider edge device being in communication with a respective redundant source of the plurality of redundant sources.
13. The system of claim 12 , wherein the provider edge device determines the flow identifier based on a global policy across each provider edge device of the plurality of provider edge devices such that each redundant source commonly associated with the multicast flow exhibits a same value for the flow identifier, the flow identifier being unique to the multicast flow.
14. The system of claim 11 , further comprising a second processor in communication with a second memory and in communication with the provider edge device, the second memory including instructions executable by the second processor to:
group the plurality of redundant sources associated with the multicast flow, the plurality of redundant sources being a subset of a plurality of sources connected to a plurality of provider edge devices over a multicast network; and
assign the flow identifier to each redundant source of the plurality of redundant sources.
15. The system of claim 14 , the second memory further including instructions executable by the second processor to:
communicate the flow identifier to one or more provider edge devices of a plurality of provider edge devices connected over a multicast network.
16. The system of claim 15 , wherein the flow identifier of the first source is communicated to the plurality of provider edge devices within a flow identifier field using a Selective P-Multicast Service Interface (S-PMSI).
17. The system of claim 14 , the second memory further including instructions executable by the second processor to:
communicate the tuple indicative of the plurality of redundant sources having common flow identifiers to one or more provider edge devices of a plurality of provider edge devices connected over a multicast network using a Selective P-Multicast Service Interface (S-PMSI).
18. The system of claim 11 , the memory further including instructions executable by the processor to:
receive a request for content of the multicast flow associated with the flow identifier; and
forward the request for content to the first source;
wherein the first source is the Single Forwarder associated with the flow identifier.
19. The system of claim 11 , the memory further including instructions executable by the processor to:
receive a request for content of the multicast flow associated with the flow identifier; and
drop the request for content;
wherein the first source is not the Single Forwarder associated with the flow identifier.
20. One or more non-transitory computer-readable media comprising computer-readable instructions, which when executed by one or more processors of a provider edge device, cause the provider edge device to:
determine a flow identifier for a first source of a multicast group, the flow identifier indicating a multicast flow associated with the first source, and the first source being associated with a first virtual private network and one of a plurality of redundant sources that are commonly associated with the multicast flow and the flow identifier, wherein the plurality of redundant sources are each connected to a Multiprotocol Label Switching network; and
elect a redundant source of the plurality of redundant sources and associated with a second virtual private network as a Single Forwarder from a tuple indicative of the plurality of redundant sources having common flow identifiers.