User`s guide

GLOSSARY
56
V.23
An ITU-T standard for modem communication at
1200 bps with a 75 bps back channel. This standard
is used in the U.K.
V.27ter
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 4800 bps. V.32 modems fall back to
4800 bps when line quality is impaired.
V.32 bis
An ITU-T standard that extends the V.32
connection range: 4800, 7200, 9600, 12,000, and
14,400 bps. V.32 bis modems fall back to the next
lower speed when line quality is impaired, fall back
further as necessary, and also fall forward (switch
back up) when line conditions improve.
See online fall back/fall forward.
V.34
An ITU-T standard that currently allows data rates
as high as 28,800 bps.
V.34+
An enhancement to V.34 that enables data transfer
rates as high as 33,600 bps.
V.42
An ITU-T standard for modem communications
that defines a two-stage process of detection and
negotiation for LAPM error control.