Quick Eagle Networks DL3800E - Manual (Page 151)

Glossary G-5
G
data link
Any serial data communication transmission path, generally between two
adjacent nodes or devices and without any intermediate switching nodes.
data link layer
In the OSI model, the network processing entity that establishes, maintains and
releases data link connections between adjacent elements in the network.
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, filters 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 flow 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.