User`s guide

G-8 DL3100 User’s Guide—November 1998
G
frame ground
A metallic layer acting as a shield, consisting of tape, braid, wire or sheath and
surrounding insulated conductors in cable. It may be the metallic sheath of the
cable or the metallic layer inside a nonmetallic sheath. It reduces stray
electrical Þelds, prevents outside electrical interference, drains off current
induced by lightning and provides for safety of personnel.
frequency
The number of repetitions per unit time of a complete waveform. The number
of complete cycles per unit of time, usually expressed in Hz.
full bandwidth DTE loopback
A loopback test that loops back the signal at the multiplexer. See also loopback.
H
HDLC (High Level Data Link Control)
Bit-oriented, data-link control protocol; any related control of data links by
speciÞed series of bits, rather than by control characters.
I
IP address
A unique, 32-bit identiÞer for a TCP/IP host on a network. IP addresses are
normally printed in dotted decimal form, such as
L
LBO (Line Build Out)
An adjustable value used to tune the attenuation between the DSU/CSU card
and the last repeater on the T1 circuit.
LED (Light emitting diode)
A device that accepts electrical signals and converts the energy to a light
signal.
LOF (Loss of Frame)
Occurs when a received digital signal loses frame synchronization.
LOFC (Loss of Frame Count)
A count of declared Loss of Frame events (ESF framing only).
loopback
A diagnostic test in which the transmitted signal is returned to the sending
device after passing through a data communications link or network. This
allows a technician (or built-in diagnostic circuit) to compare the returned
signal with the transmitted signal and get some sense of what's wrong.