3com 1.024.1644-00 Manuel D’Utilisation

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Glossary 
 
56K Voice Faxmodem Internal - User’s Guide 
 
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V.42 
An 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 
This is similar to Ymodem, except it relies on the modem for error 
checking, which makes it faster. 
 
Zmodem 
This is 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.