Glossary
Issue 3 June 2000
GL-11
L
LAN
Local Area Network
LAPD
Link Access Procedure "D"
LBO
Line Build Out — An equalizer network between the DDM-2000 OC-3 and OC-12 Multiplexers and
the DSX panel. It guarantees the proper signal level and shape at the DSX panel.
LCN
Local Communications Network
LEC
Local Exchange Carrier
LED
Light Emitting Diode — Used on a circuit pack faceplate to show failure (red) or service state. It is
also used to show the alarm and status condition of the system.
Line Timing
The capability to directly derive clock timing from an incoming OC-N signal while providing the user
the capability to provision whether switching to an alternate OC-N from a different source (as
opposed to entering holdover) will occur if the OC-N currently used as the timing reference for that
NE becomes unsuitable as a reference. For example, intermediate nodes in a linear network are
line timed. See Loop Timing.
Local
See NE (Near-End).
Locked Cross-Connection
This is a variation of the ring cross-connection that allows the user to lock the path selector to a
specified rotation of the ring. Any signal received from the other rotation of the ring is ignored.
LOF
Loss of Frame — A failure to synchronize to an incoming signal.
Loop Timing
Loop timing is a special case of line timing. It applies to NEs that have only one OC-N interface. For
example, terminating nodes in a linear network are loop timed. See Line Timing.
LOP
Loss of Pointer — A failure to extract good data from an STS-1 payload.
LOS
Loss of Signal — The complete absence of an incoming signal.
LR
Long Reach — A term used to describe distances of 40 km or more between optical transmitter and
receiver without regeneration. See IR (Intermediate Reach).
To Next Page
Loading...
Need help?
General
