3Com Courier, Reference

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G
LOSSARY
13
3Com modems can be set with the B0 command so that they use the
V.25 2100 Hz tone when answering overseas calls
V.25 bis An ITU-T standard for synchronous communications between th
mainframe or host and the modem using the HDLC or
character-oriented protocol. Modulation depends on the serial port rate
and setting of the transmitting clock source, &X.
V.27 ter An ITU-T standard for facsimile operations that specifies modulation at
4800 bps, with fallback to 2400 bps.
V.29 An ITU-T standard for facsimile operations that specifies modulation at
9600 bps, with fallback to 7200 bps.
V.32 An ITU-T standard for modem communications at 9600 bps and 480
bps. V.32 modems fall back to 4800 bps when line quality is impaired,
and fall forward again to 9600 bps when line quality improves.
V.32 bis An ITU-T standard that extends the V.32 connection range: 4800, 7200,
9600, 12K and 14.4 Kbps. V.32
bis
modems fall back to the next lower
speed when line quality is impaired, and fall back further as necessary.
They fall forward to the next higher speed when line quality improves.
V.32 terbo Modulation scheme that extends the V.32 connection range: 4800,
7200, 9600, 12K, 14.4K, 16.8K, 19.2K, and 21.6 Kbps. V.32
terbo
modems fall back to the next lower speed when line quality is
impaired, and fall back further as necessary. They fall forward to the
next higher speed when line quality improves.
V.34 An ITU-T standard that allows data rates as high as 28.8 Kbps.
V.42 An ITU-T standard for modem communications that defines a two-stage
process of detection for LAPM error control.
V.42
bis
An extension of ITU-T V.42 that defines a specific data compressio
scheme for use with V.42 error control
V.Fast Class (V.FC) Proprietary modulation scheme developed by Rockwell International for
data communication speeds up to 28.8 Kbps.
word length The number of bits in a data character without parity, start or stop bits.
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.