3Com 3C900B Installation And Operating Instructions Manual page 116

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.
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.
112
G
LOSSARY
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.