3Com U.S. Robotics 56K Voice User Manual page 50

Glossary
character
A representation, coded in binary digits, of a letter, number, or other
symbol.
characters per second (CPS)
A data transfer rate generally estimated from the bit rate and the
character length. For example, at 2400 bps, 8-bit characters with start/
stop bits (for a total of ten bits per character) will be transmitted at a rate
of approximately 240 characters per second (cps). Some protocols, like
error-control protocols, employ advanced techniques such as longer
transmission frames and data compression to increase cps.
Class 1 and 2.0
International standards used between fax application programs and
faxmodems for sending and receiving faxes.
cyclic redundancy checking (CRC)
An error-detection technique consisting of a test performed on each block
or frame of data by both sending and receiving modems. The sending
modem inserts the results of its tests in each data block in the form of a
CRC code. The receiving modem compares its results with the received
CRC code and responds with either a positive or negative
acknowledgement.
data communications
A type of communications in which computers are able to exchange data
over an electronic medium.
data compression table
A table containing values assigned for each character during a call under
MNP5 data compression. Default values in the table are continually
altered and built during each call: the longer the table, the more efficient
throughput gained.
data mode
The mode in which the faxmodem is capable of sending and receiving
data files. A standard modem without fax capabilities is always in data
mode.
44 56K Voice Faxmodem Internal - User's Guide