BGP C-multicast signaling must be enabled for an MVPN instance to use P2MP RSVP-TE or LDP as I-PMSI (equivalent to ‛Default MDT’, as defined in draft Rosen MVPN) and S-PMSI (equivalent to ‛Data MDT’, as defined in draft Rosen MVPN).
By default, all PE nodes participating in an MVPN receive data traffic over I-PMSI. Optionally, (C-*, C-*) wildcard S-PMSI can be used instead of I-PMSI. See section Wildcard (C-*, C-*) P2MP LSP S-PMSI for more information. For efficient data traffic distribution, one or more S-PMSIs can be used, in addition to the default PMSI, to send traffic to PE nodes that have at least one active receiver connected to them. For more information, see P2MP LSP S-PMSI.
Only one unique multicast flow is supported over each P2MP RSVP-TE or P2MP LDP LSP S-PMSI. Number of S-PMSI that can be initiated per MVPN instance is restricted by CLI command maximum-p2mp-spmsi. P2MP LSP S-PMSI cannot be used for more than one (S,G) stream (that is, multiple multicast flow) as number of S-PMSI per MVPN limit is reached. Multicast flows that cannot switch to S-PMSI remain on I-PMSI.