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
Extended tunnel ID
Sender template
Tunnel sender address
LSP ID
Subgroup ID originator
Subgroup ID
P2MP-TE
—point to multipoint traffic
engineering
P2MP
tree
—The ordered set of routers and TE links that
comprise the paths of P2MP TE sub-LSPs from the ingress router to all of the
egress routers.
P2MP
tunnel
—A group of one of more P2MP LSPs. A tunnel
has the following 3-tuple key:
P2MP ID
Tunnel ID
Extended tunnel ID.
PIM
—Protocol Independent Multicast
PIM-SM
—PIM Sparse Mode, see RFC 4601
PIM-SSM
—PIM Source Specific Multicast, a
subset of PIM-SM. See RFC 4601.
Pruning
—The process of removing a sub-LSP from
a a P2MP LSP.
Receiver
—A recipient of traffic carried on a
P2MP service supported by a P2MP sub-LSP. A receiver is not necessarily an
egress router of the P2MP LSP. Zero, one, or more receivers may receive data
through a given egress router.
Remerge
—A condition that occurs at an
intersecting node when two data streams belonging to the same P2MP LSP merge
into onto one data stream as they exit the intersecting node.
Sibling
LSP
—Two LSPs that belong to the same P2MP tunnel,
meaning that the session objects are the same for both LSPs.
Sibling
sub-LSP
—Two sub-LSPs that belong to the same P2MP
LSP, meaning that the session and sender template objects are the same for both
sub-LSPs.
Source
—The sender of traffic that is carried
on a P2MP service supported by a P2MP LSP. The sender is not necessarily the
ingress router of the P2MP LSP.
Tailend
router
—An egress PE router that is at the “tailend”
of a P2MP tunnel.