Question

A service provider is deploying Multicast VPN (MVPN) for a customer using the profile that leverages Multicast LDP (mLDP) in-band or default MDT signaling over an MPLS core, avoiding the need for PIM in the provider core. During validation, the network engineer must confirm how customer (C-) multicast traffic is carried across the core between PE routers when the default MDT is used with mLDP. Which statement correctly describes the behavior of the default MDT in this design?

Accepted Answer

The default MDT builds a single multipoint LSP rooted at each PE that carries all C-multicast control traffic and low-rate data streams to every PE in the MVPN, regardless of whether receivers are present.

Answer

The default MDT establishes a separate point-to-point pseudowire between each PE pair to unicast-replicate customer multicast packets across the core.

Answer

The default MDT is used only after a data MDT threshold is exceeded, at which point it forwards the high-bandwidth stream exclusively to PEs with interested receivers.

Answer

The default MDT requires PIM sparse mode in the provider core with a rendezvous point to build the shared tree that delivers customer multicast between PEs.