COMSPHERE 3800 Series Modems

automatic dial backup

When leased-line operation fails, this function forces the modem to dial the telephone

 

number stored in directory location 1; communication over the dial network continues

 

with the remote modem. For a 3800 Series modem to perform this properly, the

 

telephone number in directory location 1 must be the telephone number at the remote

 

site. Also, the Auto Dial Backup configuration option in one modem must be enabled

 

while the other modem must have the Auto Answer Ring Number configuration option

 

enabled.

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.

backbone network

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

 

network contains extended controls.

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 IBM 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.

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.

Call Setup

Top-Level menu branch that contains all the functions necessary to dial telephone

 

numbers stored in directory locations, answer incoming calls, disconnect calls, and save

 

telephone numbers to directory locations.

carrier

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

 

See data carrier.

carrier-mounted

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

 

used at central-site operations. Up to 16 modems can be installed per carrier, with 6

 

carriers per cabinet.

CCITT

An advisory committee (Consultative Committee on International Telephone and

 

Telegraph) established by the United Nations to recommend communications standards

 

and policies.

Glossary-2

November 1996

3810-A2-GB30-20

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Paradyne 3810 manual Ccitt