Digital Link DL3800 DS1, Руководство пользователя

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Glossary G-13
G
LOS (Loss of Signal)
Occurs when an input signal is detected as all zeros for 176 bit times.
loss
A reduction in signal strength, expressed in decibels.
LSC (Loopback Select Code)
An indicator describing a DSU loopback characteristic. LSC is a minimum of 35
LSC bytes of S11101F1 with secondary channel.
LT (Local Test)
A data port signal to DSU/CSU.
M
mask
Refer to subnet mask.
MIB (Management Information Base)
A structure that deÞnes what is obtainable from a network device and what
can be controlled. It has a directory listing the logical names of all information
resources residing in the network and pertinent to the network's management.
It is used to describe network management variables.
multiplexer
Any device that allows two or more users to share a common physical
transmission medium. Employed in pairs, where each device performs both
multiplexing of the multiple user inputs and demultiplexing of the channel
back into the separate user data streams.
multiplexing
The combining of multiple data channels onto a single transmission medium.
Typically, data streams are interleaved on a bit or byte basis (time division) or
separated by different carrier frequencies (frequency division).
multidrop
A communications arrangement where multiple devices share a common
transmission channel, though only one may transmit at a time.
N
NEBS
A network Equipment Building Systems requirement. A standard issued by
Bellcore that spells out central ofÞce standards for grounding, cabling and
power.