Switch User's Manual

44 L
label edge router (LER)
Resides at the network edge to initiate and
terminate label switched paths and assign
packets to forward equivalence class (FEC) as
traffic enters the Multiprotocol Label Switching
(MPLS) network.
label information base (LIB)
A table of incoming labels, outgoing labels, and
interface mappings.
label retention mode
This mode (liberal or conservative) specifies
whether or not the interface retains label
bindings that it receives
label stack
MPLS uses a label stack, which can contain
multiple labels. For example, in a stack
containing two labels, the bottom label
represents the egress Peripheral Equipment
(PE) and the top label represents the next hop
along the LSP. To move a packet across the
network, LSRs swap out the top label to forward
the packet to the next hop.
label switched path (LSP)
An end-to-end unidirectional tunnel between
MPLS-enabled routers. Data travels through
the MPLS network over LSPs from the network
ingress to the network egress.
label switched router (LSR)
A core router that operates between the source
and destination LERs in an MPLS network.
LSRs strip off the existing label and applies a
new label that tells the next-hop LSR how to
forward the packet.
label use mode
This mode (immediate or not immediate)
specifies when the interface uses the label for
the next hop.
Nortel Ethernet Routing Switch 8600
Terminology
NN46205-102 01.01 Standard
30 May 2008
Copyright © 2008 Nortel Networks
.