P
ART
III: S
ECTION
C: G
LOSSARY
137
V.22 bis
An ITU-T standard for modem
communications at 2400 bps. The standard
includes an automatic link negotiation fallback to
1200 bps and compatibility with Bell 212A/V.22
modems.
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 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.
