Which of the following about the signaling of multicast group information in an MVPN service is TRUE when MPLS P2MP tunnels are used?

In Next-Generation Multicast VPN (NG-MVPN) using MPLS P2MP tunnels, BGP is the sole control plane protocol used for inter-PE signaling. BGP is responsible for both auto-discovering remote PE routers participating in the MVPN and for signaling multicast information.

Specifically, BGP Auto-Discovery (A-D) routes, such as the Inclusive PMSI (I-PMSI) A-D route, are used to advertise the tunnel type (e.g., RSVP-TE P2MP, mLDP) and identifier for the multicast distribution tree. Concurrently, BGP C-multicast routes (Shared Tree Join and Source Tree Join) are used to signal customer-specific multicast group membership information between PEs. Therefore, BGP handles both the signaling for the PMSI and the customer multicast state.

A. mLDP and RSVP-TE P2MP are data plane tunneling technologies used to build the Provider Multicast Service Interface (PMSI) trees; they are not used for signaling customer multicast group membership between PEs.

B. PIM can be a PMSI tunnel type, but in the context of NG-MVPN with MPLS P2MP tunnels, BGP A-D is used for signaling. The second clause is also incorrect as explained for option A.

D. PIM is used for customer-to-provider (CE-to-PE) signaling within a VRF instance, not for signaling customer multicast group membership between PE routers in an NG-MVPN BGP control plane.

1. RFC 6513: Multicast in MPLS/BGP IP VPNs, Section 5, "BGP-Based Procedures", Page 8.

"This document specifies a set of BGP-based procedures for MVPNs. These procedures can be used for both auto-discovery and for exchanging C-multicast routing information among PE routers." This statement confirms BGP's dual role.

2. RFC 6514: BGP Encodings and Procedures for Multicast in MPLS/BGP IP VPNs, Section 4.3, "Inclusive PMSI A-D Route", Page 8 & Section 4.6, "C-Multicast Shared Tree Join Route", Page 13.

This RFC defines the specific BGP route types. The Inclusive PMSI A-D Route (Type 3) is used to signal the PMSI, while the C-Multicast Routes (Types 6 and 7) are used to signal customer group membership, demonstrating that BGP handles both functions.

3. Nokia 7750 SR OS R19.10.R1 VPRN Services Guide, Chapter: "Multicast in VPRN services (MVPN)", Section: "Next generation (NG) MVPN".

The guide states, "NG-MVPN uses BGP as the PE-PE control protocol to exchange C-multicast routing information." It further explains that the I-PMSI is instantiated by a BGP Intra-AS A-D route, confirming BGP's role in both PMSI signaling and C-multicast state exchange.