Forwarding Multicast Packets Over Rsvp P2Mp Lsp In The Base Router; Procedures At Ingress Ler Node - Alcatel-Lucent 7450 Manual

Forwarding Multicast Packets over RSVP P2MP LSP in the Base
Router
Multicast packets are forwarded over the P2MP LSP at the ingress LER based on a static join
configuration of the multicast group against the tunnel interface associated with the originating
P2MP LSP. At the egress LER, packets of a multicast group are received from the P2MP LSP via
a static assignment of the specific <S,G> to the tunnel interface associated with a terminating LSP.

Procedures at Ingress LER Node

The forwarding of multicast packets over a P2MP LSP follows the following procedures:
1. The user creates a tunnel interface associated with the P2MP LSP:
2. The user adds static multicast group joins to the PIM interface, either as a specific <S,G>
The tunnel interface identifier consists of a string of characters representing the LSP name for the
RSVP P2MP LSP. Note that MPLS will actually pass to PIM a more structured tunnel interface
identifier. The structure will follow the one BGP uses to distribute the PMSI tunnel information in
BGP multicast VPN as specified in draft-ietf-l3vpn-2547bis-mcast-bgp, Multicast in MPLS/BGP
IP VPNs.The format is: <extended tunnel ID, reserved, tunnel ID, P2MP ID> as encoded in the
RSVP-TE P2MP LSP session_attribute object in RFC 4875.
The user can create one or more tunnel interfaces in PIM and associate each to a different RSVP
P2MP LSP. The user can then assign static multicast group joins to each tunnel interface. Note
however that a given <*,G> or <S,G> can only be associated with a single tunnel interface.
A multicast packet which is received on an interface and which succeeds the RPF check for the
source address will be replicated and forwarded to all OIFs which correspond to the branches of
the P2MP LSP. The packet is sent on each OIF with the label stack indicated in the NHLFE of this
OIF. The packets will also be replicated and forwarded natively on all OIFs which have received
IGMP or PIM joins for this <S,G>.
The multicast packet can be received over a PIM or IGMP interface which can be an IES interface,
a spoke SDP-terminated IES interface, or a network interface.
In order to duplicate a packet for a multicast group over the OIF of both P2MP LSP branches and
the regular PIM or IGMP interfaces, the tap mask for the P2MP LSP and that of the PIM based
interfaces will need to be combined into a superset MCID.
7450 ESS MPLS Guide
configure>router>tunnel-interface rsvp-p2mp lsp-name. The
configure>router>pim>tunnel-interface command has been discontinued.
or as a <*,G>: configure>router>igmp>tunnel-interface>static>group>source ip-
address and configure>router>igmp>tunnel-interface>static>group>starg.
MPLS and RSVP
Page 165