Refer to the exhibit. This enterprise customer wants to stream one-way video from their head office to eight branch offices using multicast. Their current service provider provides a Layer 3VPN soluti

C1 and C4 may not represent the correct customer CPE endpoints for this topology, and a tunnel between those nodes would not address the head-office-to-branch multicast path.

CE1 and CE2 are managed by the service provider, so the customer cannot configure tunnels on those devices without SP involvement.

C2 and C4 are customer-controlled routers sitting behind the SP-managed CE devices. By building a GRE tunnel between these two nodes, the customer encapsulates multicast packets inside unicast GRE, allowing them to traverse the SP's L3VPN without requiring any SP multicast support. This approach is quick to deploy and scales to additional spokes by adding more GRE tunnels or migrating to DMVPN later.

2547oDMVPN is a valid scalable solution but requires significant MPLS and DMVPN configuration changes on the SP side, making it not a quick deployment.

The Draft Rosen (mVPN) solution requires the service provider to configure multicast on their PE routers, which contradicts the premise that the SP does not currently support multicast.