363-206-295
Glossary
Issue 1
December 1997
GL-11
J
Jitter
Timing jitter is defined as short-term variations of the significant instants of a digital signal
from their ideal positions in time.
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 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.