ADTRAN Express 6100 Manual page 146

Glossary
jitter
The slight movement of a transmission signal in time or phase that can
introduce errors and loss of synchronization for high-speed synchro-
nous communications. See phase jitter.
LATA
Local Access and Transport Area. One of 161 local telephone serving
areas in the United States, generally encompassing the largest stan-
dard statistical metropolitan areas. Subdivisions established as a re-
sult of the AT&T divestiture that now distinguish local from long
distance service. Circuits with both end-points within the LATA (in-
traLATA) are generally the sole responsibility of the local telephone
company, while circuits that cross outside the LATA (interLATA) are
passed on to an interexchange carrier.
loopback
A diagnostic procedure where data is sent to the device being tested,
and the output of the device is fed directly back to its input, looped
around, and the returning data is checked against that which was sent.
Media Access Control (MAC)
As defined by the IEEE, the lower of the two sublayers of the OSI ref-
erence model data link layer. The MAC sublayer is concerned with
media access issues, such as whether token passing or contention is
used.
message
The Layer 3 information that is passed between the CPE and SPCS for
signalling.
multipoint line
A communications line having multiple cable access points.
Glossary-6 Express 6100/6120 User Manual 61200176L1-1