User guide

G-6 Encore Multi-port DSU/CSU User GuideÑJuly, 1997
G
DCE (Data Circuit-Terminating Equipment)
Equipment that is either a part of the network, an access point to the network,
a network node, or equipment at which a network circuit terminates.
dial-up
Describing the process of, or the equipment or facilities involved in,
establishing a temporary connection via the switched telephone network.
digital loopback
A technique for testing the digital processing circuitry of a communications
device; may be initiated locally or remotely via a telecommunications circuit.
The device being tested returns a received test message, the results of which
are compared to the original message.
DS-0 (Digital Signal Level 0)
A 64kbit/s standard digital telecommunications signal or channel.
DS-1 (Digital Signal Level 1)
The 1.544Mbit/s digital signal carried on a T1 facility.
DS-3 (Digital Signal Level 3)
The 44.736Mbit/s digital signal carried on a T3 facility.
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.
DSU (Data Service Unit)
A device designed to connect a DTE to a digital phone line. The DSU transmits
and receives the signal and provides buffering and ßow control. The DSU and
CSU are often in the same unit. Also called a Digital Service Unit.
DSR (Data Set Ready)
A data port signal.