The Segment Routing (SR) Point-to-Multipoint (P2MP) policy removes the need for the traditional underlay signaling layers like multipoint LDP (mLDP) and P2MP RSVP-TE. A P2MP policy can be instantiated statically using the CLI on the Path Computation Element Client (PCC), or instantiated dynamically using a Path Computation Element (PCE). The PCE uses the Path Computation Element Protocol (PCEP) to program the PCC.
The P2MP policy datapath and forwarding plane use MPLS instructions, similar to mLDP and P2MP RSVP-TE, and are programmed using a replication segment object. The replication segment is a forwarding entity with an incoming label and a set of Outgoing Interfaces (OIF) and labels. A P2MP policy can be used in a Next-Generation Multicast VPN (NG-MVPN) as a provider tunnel.
This functionality is described in the following IETF drafts:
draft-voyer-pim-sr-p2mp-policy
draft-voyer-spring-sr-replication-policy
draft-dhs-spring-sr-p2mp-policy-yang
draft-hsd-pce-sr-p2mp-policy
draft-hb-idr-sr-p2mp-policy