This document describes procedures for building inter-area
point-to-multipoint (P2MP) segmented service label switched paths
(LSPs) by partitioning such LSPs into intra-area segments and using
BGP as the inter-area routing and Label Distribution Protocol (LDP).
Within each IGP area, the intra-area segments are either carried over
intra-area P2MP LSPs, using P2MP LSP hierarchy, or instantiated using
ingress replication. The intra-area P2MP LSPs may be signaled using
P2MP RSVP-TE or P2MP multipoint LDP (mLDP). If ingress replication is
used within an IGP area, then (multipoint-to-point) LDP LSPs or
(point-to-point) RSVP-TE LSPs may be used in the IGP area. The
applications/services that use such inter-area service LSPs may be BGP
Multicast VPN, Virtual Private LAN Service (VPLS) multicast, or global
table multicast over MPLS.