Digicom 3910 Return to Dial, RJ11, RJ21, Secondary channel, Select key, Serial transmission, Slot

Glossary

Return to Dial	A function available when in Dial Backup mode that allows the modem to switch to dial-line
	operation when currently on leased lines.
RJ11	A type of 6-position jack normally used with permissive dial networks and telephone sets.
RJ21	A type of 50-position jack normally used with permissive dial networks providing the appropriate
	conductors for up to eight telephone lines.
SDCP	Shared Diagnostic Control Panel. A feature that allows carrier-mounted devices to share the
	same diagnostic control panel. Installed into one COMSPHERE 3000 Series Carrier, it controls
	and monitors the devices in all the carriers in the cabinet. A single SDCP can control up to
	8 carriers, with a total of 128 devices.
SDU	Shared Diagnostic Unit. A circuit card installed in Slot 0 of the COMSPHERE 3000 Series
	Carrier that provides an interface between an optional SDCP or network management system
	and the devices in the carrier.
secondary channel	A data transmission channel with a lower signaling rate than the primary channel. It is mostly
	used for modem diagnostics.
Select key	An SDCP key that allows the selection of a specific card slot in the COMSPHERE 3000 Series
	Carrier.
serial transmission	A way of transmitting data in which bits are sent sequentially one at a time.
slot	A bay in the carrier into which a circuit card can be installed.
S-registers	Internal storage areas that contain information affecting the modem parameters.
SubHS	Sub-Network Health and Status. A display of alarm occurrences in downstream modems.
Sync Dial	A factory-preset configuration area containing configuration options most often used in
	synchronous dial networks.
synchronous	Transmission in which the data characters and bits are transmitted at a fixed rate with transmitter
transmission	and receiver synchronized. This eliminates the need for start and stop bits as used in
	asynchronous transmission, and is thus faster and more efficient.
TDM	Time Division Multiplexer. A device that enables the simultaneous transmission of multiple
	independent data streams into a single high-speed data stream by simultaneously sampling the
	independent data streams and combining these samples to form the high-speed stream.
TMp	Trellis Multipoint. A proprietary high speed, fast poll multipoint modulation scheme.
Top-Level menu	The starting point of the menu tree that displays second-level menu branches.
training	A process where two modems try to establish a connection over the telephone (voice frequency)
	line.
trellis-coded	Advanced error correction coding technique for primary data typically used on higher speed
modulation	modems. This modulation scheme uses Forward Error Correction for multipoint and high-speed
	point-to-point applications.
tributary unit	A unit that is under the control of another unit.
UL	Underwriter’s Laboratories, Inc. An organization which promotes product safety.
UNIX Dial	A factory-preset configuration area containing the configuration options most often used in a
	UNIX dial network.
upstream modem	A device connected logically closer to the host computer.
USOC	Universal Service Ordering Codes. Generic telephone company service ordering codes.
V.22	An ITU-T standard for modems operating full-duplex with asynchronous or synchronous data at
	1200 bps over the dial network (PSTN).

3910-A2-GN32-40 September 1998 Glossary-7