3Com U.S. Robotics 56K Voice User Manual page 55

Glossary
ROM
Read Only Memory is permanent memory, which is not user-
programmable.
serial transmission
The consecutive flow of data in a single channel. Compare to parallel
transmissions where data flows simultaneously in multiple channels.
start/stop bits
These signalling bits attached to a character before and after the
character is transmitted during asynchronous transmission.
terminal
A device whose keyboard and display are used for sending and receiving
data over a communications link. This device differs from a microcomputer
or a mainframe in that it has little or no internal processing capabilities.
terminal mode
A software mode that allows direct communication with the modem. This
is also known as command mode.
throughput
The amount of actual user data transmitted per second without the
overhead of protocol information such as start/stop bits or frame
headers and trailers. Compare it with characters per second.
V.8
The ITU-T standard specification that covers the initial handshaking
process.
V.17 Fax
An ITU-T standard for making facsimile connections at 14400 bps,
12000 bps, 9600 bps, and 7200 bps.
V.21
An ITU-T standard for modems operating in asynchronous mode at
speeds up to 300 bps, full-duplex, on public switched telephone
networks.
56K Voice Faxmodem Internal - User's Guide 49