Paradyne 3551 manual Doc

Glossary

Device Test	A test that uses an internal test pattern generator built into the DSU to verify that
(Devic)	the DSU (or DBM) is working properly. The generator sends a test message to the
	device's transmitter, where it is looped back to the device's receiver. The incoming
	message is then checked for errors, which are reported as Pass if there are no errors,
	and Fail if an error is found.
Diagnostic Control Panel	The face of the DSU that continuously provides status information about the DSU's
(DCP)	operation and allows an operator to manage its operation. This is a generic term
	used for both the standalone and carrier-mounted DSU models. See shared
	diagnostic control panel (SDCP) for the Model 3551.
Dial Backup Unit	An external digital or analog device, attached to the Model 3550 or 3551 DSU, that
(DBU)	is used for dial restoral (also see DBM).
dial string	A sequence of up to 36 characters that the DBM can send into the dial network to
	establish a call to a remote backup device. It consists of a telephone number and
	may include other information, such as a callback directory pointer.
Digital Loopback	A test used for manual testing of the remote end of a circuit. For example, a DL
(DL)	may be required to complete an external bit error rate test (BERT) from the remote
	DSU. The local DSU receives test data, loops it back to the transmitter, and returns
	it to the network.
Digital Test	A test used to test two DSUs and the circuit between them. Both DSUs must be
(DT)	connected to the network before this test is run.
DIP switch	Dual In-line Package switch.
DMI	Data Mode Idle. Refers to a sequence of 1s transmitted or received on the DDS
	network. When the General (Gen) branch configuration option RTS Cntrl is set to
	FrcOn, the DSU will transmit DMI whenever RTS is Off. Data Mode Idle operation
	is recommended for point-to-point applications.
DOC	Canadian Department of Communication.
drop	A tributary site.
DSR	The state of the Data Set Ready lead.
DTE Loopback	A test that allows you to test each port independently. This test loops the data path
(DTE)	at the DTE interface.
DTR	The state of the Data Terminal Ready lead.
EIA	Electronic Industries Association. This organization provides standards for the data
	communications industry to ensure uniformity of interface between DTEs and
	DCEs.
elastic store	A configuration option that is enabled in a tributary DSU to compensate for phase
	differences between DDS network timing and the received timing of an analog
	(dial) modem or DSU. It uses a buffer storage area of 16 bits.
End-to-End Test	A test used to analyze a control and tributary DSU, and the circuit between them in
(EE)	both directions independently. each DSU sends the same pattern and checks the
	incoming pattern for errors.

3550-A2-GB20-20 December 1996 Glossary-3