Read the two Cisco statements below and give me your opinion on which road to go down for a large scale multicast deployment utilizing MPLS VPN's(possible end-use use cases unknown because it is a provider environment...
From current Cisco TAC multicast training lab...
"Deploying IP multicast with PIM Dense Mode is not scalable enough for the production networks due to inherent features of the dense mode multicast protocols. Instead the PIM Sparse Mode is used in production IP multicast enabled networks.
This protocol is scalable and very appropriate for implementation in modern networks. Most current networks, whether enterprise or service provider networks, build their multicast solution on a sparse model of IP multicast."
From a currently published Cisco article...
"Cisco recommends using the Protocol Independent Module (PIM). Enabling PIM on an interface also enables IGMP operation on that interface. An interface can be configured to be in PIM dense mode, PIM sparse mode, or PIM sparse-dense mode. The mode determines how the router populates its multicast routing table and how the router forwards multicast packets it receives from its directly connected LANs ...Cisco recommends configuring an interface for sparse-dense mode."
...I have also read Cisco recommendations for PIM-SSM in MPLS VPN provider networks, because PIM Bidir (Sparse-Dense) isn't supported on all equipment. In my case, it is a 6509/3750 infrastructure.