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Admission control
|
Accounting mechanism that tracks resource information. Prevents
requests from being accepted if sufficient resources are not available.
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BGP
|
Border Gateway Protocol, which provides loop-free interdomain
routing between autonomous systems (ASs) and can act as a label distribution
protocol for MPLS.
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Branch node
|
An LSR in a point-to-multipoint LSP that is not an ingress node
or an egress node. A branch node can be connected to other branch
nodes, an ingress node, or an egress node.
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Constraint-based routing
|
A mechanism to establish paths based on certain criteria (explicit
route, QoS parameters). The standard routing protocols can be enhanced
to carry additional information to be used when running the route
calculation.
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E-LSP
|
EXP-inferred-PSC LSP. The EXP field of the MPLS Shim Header
is used to determine the per-hop behavior applied to the packet.
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Explicit routing
|
A subset of constraint-based routing where the constraint is
an explicit route
|
|
FEC
|
Forwarding equivalence class—Group of IP packets forwarded
over the same path with the same path attributes applied
|
|
Label Distribution Protocol
|
- A particular label distribution protocol used for label
distribution among the routers in an MPLS domain; represented by the
acronym LDP
- In lowercase—label distribution protocol—a
generic term for any of several protocols that distribute labels among
the routers in an MPLS domain, including BGP, LDP, and RSVP-TE. This
usage is not represented in this text by
the acronym, LDP.
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|
Leaf
|
Egress LSRs in a point-to-multipoint LSP. It is also referred
as a leaf node.
|
|
LDP
|
Label Distribution Protocol—A particular protocol used
for label distribution among the routers in an MPLS domain
This text does not use LDP to refer
to the generic class of label distribution protocols.
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|
LER
|
Label edge router—A label-switching router serving as
an ingress or egress nodes
|
|
LSP
|
Label-switched path—The path traversed by a packet that
is routed by MPLS. Some LSPs act as tunnels.
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|
LSP priority level
|
A priority that indicates the importance of one LSP relative
to another LSP. LSPs having higher priorities can preempt LSPs having
lower priorities. Priorities range from 0 through 7 in order of decreasing priority.
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|
L-LSP
|
Label-only-inferred-PSC LSP. The label value, and possibly the
EXP-bits, are used to determine the per-hop behavior applied to the
packet.
|
|
LSR
|
Label-switching router—An MPLS node that can forward layer
3 packets based on their labels
|
|
MPLS
|
Multiprotocol Label Switching—Set of techniques enabling
forwarding of traffic using layer 2 and layer 3 information
|
|
MPLS edge node
|
MPLS node that connects an MPLS domain with a node outside the
domain that either does not run MPLS or is in a different domain
|
|
MPLS egress node
|
MPLS edge node in the role of handling traffic as it leaves
an MPLS domain
|
|
MPLS ingress node
|
MPLS edge node in the role of handling traffic as it enters
an MPLS domain
|
|
MPLS label
|
Label carried in a packet header that represents a packet’s
forwarding equivalence class
|
|
MPLS node
|
A router running MPLS. An MPLS node is aware of MPLS control
protocols, operates one or more L3 routing protocols, and is capable
of forwarding packets based on labels. Optionally, an MPLS node can
be capable of forwarding native L3 packets.
|
|
Point-to-multipoint tunnel
|
The series of LSRs and links that form the path from an ingress
LSR to all of its egress LSRs. Each tunnel is uniquely identified
by a session object.
|
|
Point-to-multipoint LSP
|
An RSVP-TE LSP with a single ingress LSR and one or more egress
LSRs. Incoming data is replicated at the branch nodes.
|
|
Provider edge router
|
PE—An LER at the edge of a service provider core that
provides ingress to or egress from a VPN
|
|
Provider core router
|
P—An LSR within a service provider core that carries traffic
for a VPN
|
|
RSVP
|
Resource Reservation Protocol; E-series routers do not support
RSVP
|
|
RSVP-TE
|
Resource Reservation Protocol enhanced to support MPLS traffic
engineering; E-series routers support RSVP-TE
|
|
Sub-LSP
|
The portion of the LSP from one LSR to another LSR in a point-to-multipoint
tunnel.
|
|
Traffic engineering
|
The ability to control the path taken through a network or portion
of a network based on a set of traffic parameters (bandwidth, QoS
parameters, and so on). Traffic engineering (TE) enables performance
optimization of operational networks and their resources.
|
|
Tunnel
|
LSP that is used by an IGP to reach a destination, or an LSP
that uses traffic engineering
|
