Which multicast technology provides a large, many-to-many connectivity for a new application while minimizing load on the existing network infrastructure?

Bidir-PIM builds a single shared bidirectional tree for all sources and receivers, eliminating the need to maintain per-source (S,G) state entries on every router. This significantly reduces memory and processing load across the network infrastructure, making it optimal for large many-to-many deployments where numerous sources send to the same multicast group.

PIM Sparse Mode builds per-source (S,G) trees after initial shared tree use, generating higher router state load in many-to-many scenarios with multiple active sources.

Any-source Multicast (ASM) is a service model that encompasses PIM-SM behavior, not a distinct protocol mechanism that reduces infrastructure load for many-to-many communication.

Source Specific Multicast (SSM) is optimized for one-to-many delivery from a single known source and does not support many-to-many multicast applications.