Multicast Communication Deployment

PIM-SM/MSDP/MBGP
Current Inter-domain multicast routing protocols for IPv4
Any-Source Multicast (ASM) support (aka (*,G) join/leave)
Scalability
3rd-party dependency problem
Traffic concentration problem
Flood MSDP Source Active (SA) message
Complexity
Manage both RPT and SPT
Need MSDP peer RPF check