BIDIR-PIM is designed to be used for many-to-many applications within individual PIM domains. Multicast groups in bidirectional PIM mode can scale to an arbitrary number of sources without incurring overhead due to the number of sources. https://www.cisco.com/c/dam/en/us/products/collateral/ios-nx-os-software/multicast- enterprise/prod_white_paper0900aecd80310db2.pdf