NG-MVPN multicast source geo-redundancy

Multicast source geo-redundancy is targeted primarily for MVPN deployments for multicast delivery services like IPTV. The solutions allows operators to configure a list of geographically dispersed redundant multicast sources (with different source IPs) and then, using configured BGP policies, ensure that each Receiver PE (a PE with receivers in its C-instance) selects only a single, most-preferred multicast source for a specific group from the list. Although the data may still be replicated in P-instance (each multicast source sends (C-S, C-G) traffic onto its I-PMSI tree or S-PMSI tree), each Receiver PE only forwards data to its receivers from the preferred multicast source. This allows operators to support multicast source geo-redundancy without the replication of traffic for each (C-S, C-G) in the C-instance while allowing fast recovery of service when an active multicast source fails.

Figure: Preferred source selection for multicast source geo-redundancy shows an operational example of multicast source geo-redundancy:

Figure: Preferred source selection for multicast source geo-redundancy

Operators can configure a list of prefixes for multicast source redundancy per MVPN on Receiver PEs:

A Receiver PE selects a single, most-preferred multicast source from the list of pre-configured sources for a specific MVPN during (C-*, C-G) processing as follows:

BGP policy on Type-5 SA advertisements is used to determine the most preferred multicast source based on the best local preference as following:

Operators can change redundant source list or BGP policy affecting source selection in service. If such a change of the list/policy results in a new preferred multicast source election, make-before-break is used to join the new source and prune the previously best source.

For the correct operations, MVPN multicast source geo-redundancy requires the router:

MVPN multicast source redundancy solutions is supported for the following configurations only. Enabling the feature in unsupported configuration must be avoided.