Glossary - Cisco ASR 920 Series Configuration

Glossary

Glossary
Branch router —A router that has more than one directly connected downstream routers. A router where
packet replication occurs.
Bud router —An egress router that has one or more directly connected downstream routers. A bud node can
be a branch node and a destination.
Crossover —A condition that occurs at an intersecting node when two or more incoming sub-LSPs that
belong to the same LSP have different input interfaces and different output interfaces.
Egress router —One of potentially many destinations of the P2MP TE sub-LSP. Egress routers may also be
referred to as tailend routers, leaf nodes, or leaves.
Data duplication —A condition that occurs when an egress router receives duplicate packets. The condition
can happen as a result of re-optimization of LSPs, remerge, or crossover. It causes network bandwidth to be
wasted and should be minimized.
Grafting —The process of adding a new sub-LSP to a P2MP TE tunnel.
Headend router —An ingress PE router that is at the "headend" of a P2MP tunnel.
Ingress router —The router that initiates the signaling messages that set up the P2MP TE LSP. Also known
as the headend router.
MDT —A Multicast Domain/Distribution tree in the core that carries traffic and/or control messages for a
given VPN. An MDT implicitly implies that we are discussing the Domain-Model. And MDT can have
multiple types of encapsulation in the core, for example, GRE, IP-in-IP or MPLS.
MFI —MPLS forwarding infrastructure.
mLDP —Multicast signaling extensions to LDP
P2MP ID (P2ID) —A unique identifier of a P2MP TE LSP, which is constant for the whole LSP regardless
of the number of branches and/or leaves.
P2MP LSP —One or more source to leaf sub-LSPs. It is identified by 5-tuple key:
Session
• P2MP ID
• Tunnel ID
• Extended Tunnel ID
Sender Template
• Tunnel sender address
• LSP ID
P2MP Sub-LSP —A segment of a P2MP TE LSP that runs from the headend router to one destination. A
sub-LSP is identified by the following 7-tuple key:
P2MP session
• P2MP ID
• Tunnel ID
MPLS Traffic Engineering Path Calculation and Setup Configuration Guide, Cisco IOS XE Release 3S (Cisco
ASR 920 Series)
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MPLS Point-to-Multipoint Traffic Engineering