Asynchronous Communication

A form of data transmission in which bits are transmitted without the use of a synchronising clock signal. Instead, each character is delivered with a start and stop bit surrounding it to indicate the beginning and end of the information. This is in contrast to synchronous communication, when data is delivered in blocks utilising a […]

Audio Menu

A verbal option provided by a phone recording. Audio selection menus are common in automated attendant, interactive voice response, and fax-on-demand systems. They are caller input prompts. Audio menus can direct you to speak commands or press keys on a touch-tone keypad.

Audio Response Unit (ARU)

A computer telephony system that uses voice storage and forwarding technology. ARUs can be passive or interactive. Passive ARUs simply play messages, whereas interactive ARUs play messages based on caller input.

Audio Teleconferencing or Audio Conferencing

Today’s PC-based systems allow for the use of conference bridges. You can set up, attend, and manage your own conferences over any touch-tone telephone by installing a conference server on your voice networks. Users can also schedule meetings using desktop software from their e-mail systems or a web browser.

Conference Bridge

A device that allows multiple parties to communicate over the phone. Conference bridges can be manned by a proctor or operator, or they can be supervised. Some PBXs (Private Branch Exchange) include standalone conference bridges as well as conference bridge functions These systems include circuitry that sums and balances the energy (noise) on each channel […]

Digital Subscriber Line (DSL)

A high-speed digital switched service that connects subscriber CPE (customer premises equipment) to the CO via existing copper pairs (central office). DSL handles more data downstream (data flowing towards the subscriber) than upstream (data flowing away from the subscriber) (flowing towards the network).


The designation for the 2.048 Mbps ITU standard for Europe’s 30-channel digital telephone service. It is the European version of T-1 (DS-1). The bandwidth is divided into 2 signaling channels (channels 15 and 31 starting from 0) and 30 bearer channels (voice channels). A&B bit signaling (robbed bit signaling) is not used here. E-1 uses […]

Full Duplex

Full duplex refers to the ability of both ends of a communication to send and receive information at the same time without degrading the quality of the content.

Frame Relay

Frame Relay is a packet switching method used in data communications that uses available bandwidth only when it is required. With proper network management, this fast packet switching method is efficient enough to transmit voice communications.

Fax Server

A fax machine that is computer-based. Fax servers are “shared use” devices that are typically installed on a local area network (LAN). Clients on the LAN can access the fax server from their PCs in the same way that they access a network-based (shared) printer. Users can generate faxes at their workstations and have them […]