During the analaysis of one of our client network running MPLS in the core and having lot of customers which are on MVPN. Core is using sparse-dense mode but with no RP and customers are using static RP mapping. The main disadvantages of using this type of topology is that if the core wonot be able to find the RP then it will fall back to the dense mode. So in the scenarios where no RP is defined will alwasy fall back to the dense mode which means unnecessary flooding of stream to each and every vrf which is the part of that VPN. By using this the main problem is that data mdt can never converge in the VPN, it it means if you are using data mdt then there is no use of that becasue your tree is *,G and data mdt is for S,G; It means never S,G entry will come and data mdt will never converge. To overcome the problem need to define the RP address in the core & RP should be specifically for the data MDT groups. RP can be defined by using AUTO-RP or BSR.