Digital Link DL3800 DS1, Руководство пользователя

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G-10 DL3800 DS1 Inverse Multiplexer User Guide—February 1999
G
DSU/CSU (Data Service Unit/Channel Service Units)
The pair of communications devices that connect an in-house line to an
external digital circuit. At the customer's end of the telephone connection, the
DSU/CSU takes data from terminals and computers, encodes it, and transmits
it down the link. At the receive end, another DSU/CSU equalizes the received
signal, Þlters it, and decodes it for interpretation by the end-user.
DSX-1 (Digital Signal Cross Connect Level 1)
Parameters set used when DS-1 signals are cross connected.
DTE (Data Terminal Equipment)
Terminal equipment connected to the DSU and used for communication over
digital networks. May be a terminal, computer, printer or multiplexer.
DTE loopback
An EIA-232-D signal which indicates that the DTE is ready for operation.
DTR (Data Terminal Ready)
Signal from DTE to DSU/CSU.
E
EER (Excessive Error Rate)
Determined by counting the number of T1/T3 code violations during a time
interval.
EFS (Error Free Seconds)
Occurs when a second is free of CRC-6 violations or Out of Frame (OOF) events
or one or more BPV or OOF events.
EIA (Electronic Industries Association)
An organization which sets data communication industry standards.
encoding/decoding
The process of reformatting information into a format suitable for
transmission, and then recovering it after transmission.
equalization
The spacing and operation of ampliÞers so that the gain provided by the
ampliÞer, per transmission frequency, coincides with the signal loss at the same
frequency; circuitry that compensates for the differences in attenuation at
different frequencies.
ES (Errored Second)
Occurs when a second has one or more OOF events or CRC violations or with
one or more BPV or OOF events.