US Robotics SportsterVoice User Manual page 35

V.42
A ITU-T standard for modem communications that defines a two-stage process of detection and negotiation for
LAPM error control.
V.42 bis
An extension of ITU-T V.42 that defines a specific data compression scheme for use during V.42 connections.
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.
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.
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