Used in ISDN. This channel transmits call control information (out-of-band signaling) for B-channels. The D-channel is a logical, not a physical channel.

Modem system designed to handle a variety of real-time applications, process control and high-speed data. Individually tailored to meet specific user requirements.

Optional device that connects to Toshiba 2000-series digital telephones to provide the telephones with 20 flexible feature buttons that can be assigned individually for Direct Station Selection, System and Personal Speed ...

Fiber-optic cable leased from one carrier to another without accompanying transmission service support and opto-electronic connections. Sometimes used to bypass a local exchange carrier’s facilities.

A dB is a unit of measure of signal strength, usually the relation between a transmitted signal and a standard signal source. Every 3dB equals 50% of signal strength; therefore a ...

A peripheral hardware unit compatible with designated digital telephone circuits that supports optional door phone s(MDFBs) and provides door lock control.

A device that helps facilitate the processing of a heavy load of incoming calls. The DDSS connects only to designated digital telephone circuits, and is associated with a digital telephone.

Connection between a customer’s premises and an interexchange carrier (IXC). All transmissions on this dedicated line are automatically routed to the IXC. Provided by a local exchange carrier (LEC), alternate access ...

Permanently assigned path to specific data terminals which is not part of a switched network. Synonym: private line or dedicated transport.

The point of interconnection between telephone company terminal equipment and your building wiring. The protective apparatus or wiring at a subscriber’s premises.

In telecommunications, a “device” is the physical interconnection outlet. “Equipment” (a computer, phone, fax machine, etc.) then plugs into the device.

Incoming PBX or centrex calls completed to extensions without the assistance of an operator.

Digital Telephone

Period during which a computer, communications line or other device is not operating correctly because of mechanical or electronic failure.

Outside wire pair(s) from the telco plant (cable) to a house or building for connection to a protector.

A group of enhanced speed digital services that run on twisted pair wires. They carry both voice and data.

FCC-mandated interface device for direct connects between customer premises equipment (CPE) and a data-provisioned local exchange carrier (LEC) facility.

Type of signaling which combines two distinct frequencies for each indicated digit.