if I understand very well, Bidirectional PIM maske sure that the multicast traffic always flow through the RP. Also the Multicast router will always ue (*,G) instead of (S,G).
Thanks for your input. [:)]
Yes exactly, it suits best with many sources and so avoid maintaining lots of source-specific states. In upstream you have your traffic from the sources to the RP (the DF avoids loops) and on downstream this the traffic from the RP to the receivers (like SM).