A customer is using a service provider to provide a WAN backbone for a 30-site network. In establishing the network, the customer must work within these constraints: - The customer has a self-managed

Configuring static GRE tunnels over the VPLS backbone allows the customer to run its self-managed MPLS network inside those tunnels, so multicast VPN traffic is encapsulated as unicast GRE packets before entering the provider network. Because the provider only sees unicast GRE traffic, it routes rather than floods the packets, and multicast replication decisions remain under the customer's control within the MPLS/mVPN domain.

Label Switched Multicast using mLDP or RSVP-TE P2MP requires multicast-capable label switching in the provider core, which is not available in a VPLS-only backbone.

PIM-SSM with IETF Rosen Draft mVPN still relies on the provider network to replicate multicast traffic selectively, which requires PIM snooping support that the VPLS backbone explicitly lacks.

Configuring static multicast-to-MAC address mappings only affects local Layer 2 flooding decisions on a switch and does not control how the VPLS provider replicates multicast frames across the WAN.

GET VPN encrypts traffic but does not change how the VPLS provider handles multicast replication, so multicast packets would still be flooded to all VPLS sites.