AT&T DataPort PCX Modem User Manual page 84

Glossary
V.32
A CCITT standard for modems operating full-duplex with
asynchronous or synchronous data at 9600 or 4800 bps over
dial or leased telephone lines.
V.32bis
A CCITT standard for modems operating full-duplex with
asynchronous or synchronous data over dial or leased
telephone lines at 14,400, 12,000, 9600, 7200, or 4800 bps.
V.42
A CCITT standard for error control protocol.
V.42bis
A CCITT standard for data compression.
X
XOFF
A character that tells the computer or modem to stop
transmitting data.
XON
A character that tells the computer or modem to resume
transmitting data.
GL-12
Issue 2 July 1995