Procedures At Egress Ler Node - Alcatel-Lucent 7450 Manual

Forwarding Multicast Packets over RSVP P2MP LSP in the Base Router

Procedures at Egress LER Node

Procedures with a Primary Tunnel Interface
The user configures a tunnel interface and associates it with a terminating P2MP LSP leaf using
the command: config>router>tunnel-interface rsvp-p2mp lsp-name sender sender-address.
The configure>router>pim>tunnel-interface command has been discontinued.
The tunnel interface identifier consists of a couple of string of characters representing the LSP
name for the RSVP P2MP LSP followed by the system address of the ingress LER. The LSP name
must correspond to a P2MP LSP name configured by the user at the ingress LER and must not
contain the special character ":" 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.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 egress LER accepts multicast packets the following methods:
1. The regular RPF check on unlabeled IP multicast packets, which is based on routing table
2. The static assignment which specifies the receiving of a multicast group <*,G> or a
One or more primary tunnel interfaces in the base router instance can be configured. In other
words, the user will be able to receive different multicast groups, <*,G> or specific <S,G>, from
different P2MP LSPs. This assumes that the user configured static joins for the same multicast
groups at the ingress LER to forward over a tunnel interface associated with the same P2MP LSP.
A multicast info policy CLI option allows the user to define a bundle and specify channels in the
bundle that must be received from the primary tunnel interface. The user can apply the defined
multicast info policy to the base router instance.
At any given time, packets of the same multicast group can be accepted from either the primary
tunnel interface associated with a P2MP LSP or from a PIM interface. These are mutually
exclusive options. As soon as a multicast group is configured against a primary tunnel interface in
the multicast info policy, it is blocked from other PIM interfaces.
However, if the user configured a multicast group to be received from a given primary tunnel
interface, there is nothing preventing packets of the same multicast group from being received and
accepted from another primary tunnel interface. However, an ingress LER will not allow the same
multicast group to be forwarded over two different P2MP LSPs. The only possible case is that of
Page 166
lookup.
specific <S,G> from a primary tunnel-interface associated with an RSVP P2MP LSP.
7450 ESS MPLS Guide