3Com 005683-00 Manual page 91

V.42 bis
An extension of ITU-T V.42 that defines a
specific data compression scheme for use
during V.42 connections.
2
X
A technology that uses the digital telephone
network to increase the bit rate of the receive
channel by eliminating the analog to digital
conversion commonly found in modem
connections. 2 connections require an
X
capable modem calling a digitally connected
2 capable host.
X
Xmodem
The first of a family of error control software
protocols used to transfer files between
modems. These protocols are in the public
domain and are available from many bulletin
board services.
G
LOSSARY
XON/XOFF
Standard ASCII control characters used to
tell an intelligent device to stop/resume
transmitting data.
Ymodem
An error-checking protocol that can send
several files of data at a time in 1024-byte
(1K) blocks. This protocol can use either
checksums or CRC for error checking.
2
X
Ymodem G
Similar to Ymodem, except it includes no error
checking, which makes it faster.
Zmodem
Similar to Xmodem and Ymodem, except it
includes batch transfer, the ability to recover
from a partially complete transfer, an autostart
feature, and improved efficiency
87