COMSPHERE 392xPlus Modems

automatic dial standby

When operating in Dial Backup mode, this function forces the modem to periodically

 

check the quality of the leased line. If the leased line is found to be at normal operating

 

condition, the modem disconnects from the dial network and continues normal operation

 

over the leased-line network.

automatic rate control

Modems adjust their signaling rate based on current line conditions.

backbone network

The primary route from a control modem to its first tributary when the communications

 

network contains extended control modems.

backplane

A common bus at the rear of the COMSPHERE 3000 Series Carrier connecting each

 

circuit card slot to the SDCP and/or SDU. It also distributes low-voltage ac power to

 

each slot.

baud

A unit of signaling speed that is equal to the number of symbols per second. This is not

 

necessarily the same as bits per second, although the terms are frequently interchanged.

Bisync

Binary Synchronous Communications. An IBMr communications protocol that has

 

become an industry standard. It uses a defined set of control characters and

 

control-character sequences for synchronized transmission of binary-coded data between

 

stations in a data communications system.

bit

A contraction of binary digit. A bit, which is the smallest unit of information, represents

 

the choice between a one or a zero (sometimes called mark or space).

bps

Bits per second. Indicates the speed at which bits are transmitted across a data

 

connection.

broadcast

A method of transmission. The simultaneous transmission to two or more

 

communicating devices.

buffer

A storage device used to compensate for differences in the data flow rate when

 

transmitting data from one device to another.

byte

A sequence of successive bits (usually eight) handled as a unit in data transmission.

carrier

The rack mounting that contains 17 slots: 1 control slot for an SDU and 16 modem slots.

 

See data carrier.

carrier-mount

A modem that is designed for installation in a COMSPHERE 3000 Series Carrier and

 

used at central-site operations.

CCITT

An advisory committee (Consultative Committee on International Telephone and

 

Telegraph) established by the United Nations to recommend communications standards

 

and policies.

channel

A path for electrical transmission between two or more points. Also called a circuit, line,

 

link, path, or facility.

character

A letter, figure, number, punctuation, or other symbol.

character echo

A way to check the accuracy of data transmission by sending to the monitor (displaying)

 

all the characters being transmitted.

Glossary-2

November 1996

3920-A2-GN31-30

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Paradyne 392xPLUS Automatic dial standby, Automatic rate control, Backbone network, Backplane, Baud, Bisync, Bit, Bps