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 |
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 |
| 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 |
| |
| 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. |
| A modem that is designed for installation in a COMSPHERE 3000 Series Carrier and |
| used at |
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. |
November 1996 |